REVIEW
Hayes Dominion A4 Brakes - Three Years Later
Dominion
I've been working on the introduction to this piece 'forever'. How long is forever? I've been riding this same brake system since November 2019, so I'm almost half a year late for our three-year anniversary.
I want to both say that Hayes Dominion A4 brakes are rad and also explain why they're not everywhere all the time, and you might not have even seen them once. I want to justify the fact that they're ugly and celebrate the fact that the lever blades are as smooth and play-free as the day I installed them.
The rear caliper pistons still move freely, which is strange in my experience.
The lever is as smooth and play-free as the day I installed them, on original bearings.
The only service they've seen is the odd brake bleed when I'm installing fresh pads.
When Hayes stepped up to make their first truly relevant brakes since the champagne Mag in the late '90s, they compromised nothing. They're not light, they're not pretty, and they're not cheap. Not that 250 USD per wheel for aftermarket brakes is on another planet, but there's simply not the huge difference between OE cost and SRP that's built into some other brake systems.
I commend Hayes for sticking to their guns here since it's fair to say that chasing OE spec is what first drove their brake systems into mediocrity ages ago. They're earning Dominion customers one rider at a time by making a great product that's intuitive to use and easy to support after the sale.
I generally bleed the Dominions when changing pads. The fluid always comes out clean and clear so I could certainly stretch it much longer.
A Hayes bleed is always a one-and-done process. I bleed them the same way as any SRAM brake.
Compounding
My friend Mechanic-Mark and I were out in the woods the other day when I noted that maybe, just maybe, I was due a fresh set of pads on these Hayes Dominion brakes. It’s the darndest thing though because despite having as much bite as anything I’ve ever used the pads just seem to run forevermore.
“They must be loud,” said Mark. I don’t know about that, they don’t howl any more than my other brakes when they’re wet and cold. But actually, after he said it, in regular dry conditions, they do present more metallically, more sintered-noisily, than other pads I’ve tried.
Now, Mark has been wrenching in his family’s automotive shop longer than I’ve been alive, and over the years I've picked up lots of interesting bicycle-and-car comparables from him, but suffice it to say that generally there's friction, wear, and noise and companies have to choose what they optimize.
When there's less than a dime, it's replacement time!
The T100 Dominion pads bite hard and last a long time.
I know that Hayes put a lot of effort into testing different brake systems - including having staff and athletes ride Magura's excellent MT7 brakes extensively as a comparable - and pad compounds and I understand why the T100 was the winner. I'll trade a bit of noise for consistent, excellent braking bite and long life.
For folks that prefer a silent setup, I've also run their T106 semi-metallic pads. The braking bite is still good and pad life is similar to other resin and semi-metallic pads I've used from Shimano, SRAM and Magura. I'd recommend the T100 pads to everyone, but for Dominion owners riding the T106, I'd be curious to hear about your preference.
Looking back at my teardown piece from November 2019 was a funny reminder that I've been on these brakes longer than I've owned my Walt V2.
I miss taking things apart and putting them back together with BikeRoom-Jeff. He's still teaching wrenching and shop management, but out in Kaslo, BC.
DOT v. DOT
A quick aside about DOT fluid and the interchangeability of DOT 4 and DOT 5.1. In their Ultimate series brakes, SRAM is using DOT 5.1 and in all their other brakes the specification is for DOT 4. I just bled these Dominions with DOT 5.1 (which is what they are shipped with), because it's what I had on hand, and the last time I bled them I used DOT 4 for the same reason. I certainly don't notice a difference.
I reached out to SRAM about the spec choice and was surprised that it doesn't come down to an OE cost difference in fluids, but rather a performance choice.
DOT 5.1 has a higher boiling point and they feel it's the superior option for riders pushing their brakes to the limit and more regularly servicing their bikes to maintain optimum performance. DOT 4 is less hygroscopic so it will perform consistently and longer between brake bleeds.
The Hayes Pro Bleeder kit includes DOT 5.1 brake fluid, which is what comes installed in the Dominion brakes.
I used 5.1 for this bleed, as it's what was on hand, but the less hygroscopic DOT 4 is likely a better choice for my use case.
LOFI
Hayes refers to the Dominion A4 as being Low Input and High Fidelity (LOFI), by which they mean the brake system requires very little effort at the lever blade to deliver a "predictable, progressive ramp-up and a crisp bite point." It's not just marketing. These brakes have a very light lever action that Cam & I covered in our paired reviews.
I'm not going to go out and claim that any system is "the best" on the market, but for any rider managing hand cramping or fatigue, I recommend trying these brakes. I'm still thrilled with the performance on long steep descents and now that I'm used to that feathery action, from initialization all the way through full-stop, every other brake I've ridden takes some recalibration.
I've received a bit of criticism for testing World Cup DH lever brakes on my rigid single-speed. All I can really say in response is that folks have to choose how much salt to sprinkle (or dump) on any review they read.
From my viewpoint, these are the easiest brakes I've ridden in terms of maintaining grip down steep, greasy, janky North Shore trails without the benefit of suspension. It's a bonus that they still work like new.
There aren't many bicycle products and certainly no other brakes I can think of that feel like new after this much trail time with this little maintenance. The only thing that comes to mind is my Chris King bottom bracket - and that takes longer to regrease than it takes me to bleed these brakes.
I had considered doing another teardown piece, but really what's the point if they work like new after a basic bleed? Hayes even offered to send a rebuild kit for the calipers, but all eight pistons still move freely.
They're not sexy, but they're smooth, strong, and ultra-reliable. Plus, they are a fast favourite of everyone who gives them a shot and they still seem fresh almost three-and-a-half years into our relationship.
If you're Dominion A4 curious, there's much more information available at Hayes Bicycle.
Comments
Generalist Grant
1 year, 1 month ago
This comment has been removed.
Andrew Major
1 year, 1 month ago
Thank you Grant. If you’d ever seen me ride you’d know I’m definitely an average mountain biker! Ha.
Since my earliest days working in shops I’ve had a serious hang up about spending other peoples’ money for them (I’m a shitty up-sales person) and I take that approach to writing too.
The bite difference should be very notable; I would recommend cleaning and lightly sanding your rotors before bedding in the new pads if it’s not something already on your to-do list.
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Generalist Grant
1 year, 1 month ago
This comment has been removed.
Ripbro
1 year, 1 month ago
Andrew, do you rough up new rotors or do you only do this for new pads?
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Andrew Major
1 year, 1 month ago
I don't. Brand new rotors I just bed in the pads. When I'm changing pads for exactly the same pads I don't usually touch the rotors either - just a quick wipe down with some ISO.
But if I'm changing pad compounds on my own brakes or if I'm working on a bike at the shop where the pads I'm changing out are squealing/potentially contaminated/different then I'll ISO and sand the rotors just to give the new pads their best chance.
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Ripbro
1 year, 1 month ago
Thanks. That’s the way I have done things in the past as well.
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Andrew Major
1 year, 1 month ago
I don’t know that there’s a right way or best practice but that’s always done me right at home and in the shop.
Duncan Wright
1 year, 1 month ago
Re: big brakes on the singlespeed
Obviously you don't need me to tell you this, but for the life of me I don't understand why anyone save perhaps world-cup level XC riders would ride anything less than the most powerful brake they can reasonably afford on every bike they own.
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Andrew Major
1 year, 1 month ago
I understand folks who count grams wanting to get the most power for a given amount of weight but I don't count grams so I'm bought in.
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gubbinalia
1 year, 1 month ago
This well-and-truly-long-term review feels timely to me as I just last night bled a fresh set of the T2 levers into my three-year-old Dominion A2 brakeset (purchased not long after the original Major/McRae dual review back in 2020!) Prior to Hayes I was a longtime pro-Shimano, anti-ServoWave brake-selector, which meant a lot of $$ dumped into old-stock XTR Race levers paired with XT or SLX 2- or 4-pot calipers. I was hesitant to jump ship, but the meteorically rising cost of all things Shimano, and the funky ergonomics of the 9100 levers, had me looking for something else. The original NSMB review, coupled with feedback from one of Hayes's early brake testers on the Path Podcast, validated trying the Dominions... which, without a doubt, have been the most reliable brakeset I've ever been on.
I will sing the praises of the A2 system all day long, for pretty much any XC/trail/all-mountain-ish bike, but I know many (almost all) the folks I've seen move to Hayes in the past 2-3 years have gone to the A4s, "because it weighs the same but gives you more power, ya know?" Having briefly tried the A4 system (on a Stumpy Evo) as well, however, I'm not sure the gains in outright power make up for the increased difficulty modulating the brake to not grab too hard at slow speeds -- at least, for more XC-oriented riders like myself, rather than someone who's running these on a full winch-and-plummet rig. The A2s still have phenomenal top-end power once they're bedded in (and I'm 6'3", 215lbs, so not exactly a flyweight.) The A2's added modulation at lower speeds, e.g. on a rolling section over some off camber wet roots, in not fearing that I'll lock up the rear wheel and start swapping ends is noticeable.
Re. T106 semi-metallic pads, I pretty much never run the full metallic pads because I'm just not on long enough descents here in central VT to heat up the metallic compound to a point where it grabs as smoothly and equally as the semi-metal. Maybe it's something wrong with my bedding technique on the metallics, but I've found that the super-grabby initial bite of the metallics doesn't feel nearly as good as the consistent pull of the semi-metals, at least until I've been descending for 10-15mins (which is relatively rare around here). I also think the semi-metals are pretty darn good in the wet, at least for XC/trail-ish applications, compared with any of the traditional organic pads from Shimano, etc. (Also, if you're running the Dominion T2 system, the ever-so-slightly lesser piston retraction in that slimmed-down caliper means that the T100s are a fraction too draggy and loud for my preference.)
Thanks AM for the great review and thorough (multi-part, even) follow-up!
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Ripbro
1 year, 1 month ago
Thanks for posting your thoughts on the A2s. My wife has guides that are due for replacement, the A2 seem like the perfect fit.
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gubbinalia
1 year, 1 month ago
@Ripbro, highly recommended -- I had a number of customers at the LBS where I worked who went that route (Guides/G2s --> Dominion A2s). If your wife uses 180mm rotors on the current SRAM setup she could likely even downsize to a 160mm rear rotor for the A2s, to keep modulation high on the rear wheel.
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Andrew Major
1 year, 1 month ago
Cheers!
I’ve not ridden the A2 but I have a lot of compare/contrast time on Formula’s Cura 2 vs. Cura 4 and there are certainly situations, weight aside, where the Cura 2 would be the superior choice.
I’d certainly be curious to try the 2-piston setup, though generally in the steep/janky local terrain more power is always better.
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gubbinalia
1 year, 1 month ago
The Cura 2 vs. Cura 4 comparison makes sense -- I have a friend with a set of each and it sounds like he notices a pretty big advantage to the 2's when modulation is at a premium. It also sounds like the power differential is bigger between the Cura 2/Cura 4 as it is between the Dominion A2/A4, perhaps?
Knowing you are also a sedulous surveyor of semi-slicks, I feel like the A2 with semi-metal pads is the natural choice for a rear wheel when running a not-so-grippy rear tire.
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Andrew Major
1 year, 1 month ago
It's funny you should mention mounting more lubricious loafers - I have a fresh Purgatory to go on my single-speed and I was thinking this morning that the semi-metallic pads may have been the more palatable pairing on the back.
Neither Cura model are comparable to Shimano's light switches, but the Cura 2 has a more positive feeling at the lever. That said, I haven't ridden the new Cura 4 master cylinder assemblies with the slightly updated geometry. The Cura 2 does have a lot of bite, I'd put them ahead of any 2-piston system I've ridden BUT, I haven't been on the A2.
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Steven Hambleton
1 year, 1 month ago
Not to mention the Cura 2 has seen downhill race action (and podium places?). I've heard the Cura 4 suffers from sticky pistons whereas the Cura 2 is virtually fault free.
Oh and Formula brakes are available in polished silver ;)
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Andrew Major
1 year, 1 month ago
I've worked on a fair few Cura 4 systems including mine, my brothers, and at the shop. I haven't seen any particular issues with pistons sticking.
The Cura 2 certainly feels more positive at the lever - I was out on my commuter today running errands and it's one of the nicest feeling brakes around certainly. But the Cura 4 clearly has more stopping power.
Actually, as crappy as they are for actual stopping, the other brakes I'd compare to the Cura 2 in terms of the lever engagement are the classic XTR M975 brakes and the current Level Ultimates. Neither of those are winning any DH races though.
They do look awesome in silver.
danimaniac
1 year, 1 month ago
AND! You get the Cura2 as a Flatmount Brakecaliper.
As first MTB manufacturers started to incorporate rear FM mounts that's a USP for MTB brakes.
danimaniac
1 year, 1 month ago
The power differential is quite big on the Curas!
The Cura 4 has two paris of 18mm diamter pistons -> 1018mm² of surface area to distribute power.
Cura 2 904,8, like the Dominion A2 (see my other comment below/above about the comparison of Dominions).
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danimaniac
1 year, 1 month ago
Well you know what?
The outright power of the A2/T2 is only marginally lower than the A4/T4
we could now go down a rabbithole of physics and stuff like that but in the end only thing changed for the pressurized system ist the caliper area distributing force through the pads to the rotor and that is:
A2/T2 (24mm diameter) 904,8mm²
A4/T4 (2x 17mm diameter) 907,9mm²
That's it. you also get a bit more "rubbing" because the pad-size is different. Most gains from going 4-pot will be better heat management, better pressure distribution and therefore a bit better braking.
Thanks Andrew for the review.
about three years ago I bought the A4s because of your review and cannot be more happy about them!
I never bled them, I only changed pads and lubricated the pistons and put a tiny drop of chain lube on the chirping lever that killed all noise for good. (Lever was chirping like a little sparrow when you would release it).
I will bleed them this season though. Just because I now have the bleedkit :d
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06hokieMTB
1 year, 1 month ago
Long, long, long time Shimano fan here. 2-pot, 4-pot, I was dang near evangelical with my appreciation for Shimano brakes (and my dislike of the feel of SRAM brakes).
Last year I took the opportunity to switch it up. I first ran TRP DH-R EVO's (which are fantastic, btw) as a proof of concept to cure me of my Shimano addiction... Then, on recent bike builds, I broke my long standing disdain for DOT fluid brakes and gave the Hayes Dominion A4's a try. I was impressed. I have since built my second bike with Dominion A4's. They're good, y'all.
Given the option, I still prefer mineral oil, mainly because I can be messier during bleeds and not worry as much. Also, I like how you can buy a liter of pink Shimano mineral oil from Jenson and just store in the garage.
Know what I don't miss? Having to do regular lever bleeds on my old Shimano brakes and having the fluid come out nasty/black in short time. Also don't miss having to deal with the brakes feeling weird if you store the bike vertically (or, even worse, hang it upside down). Lastly, I love that Hayes sells full rebuild kits. I can see me moving my Dominions to future builds.
If you're in the market for new brakes, I would highly recommend looking beyond the two "S" brands. I guess I'd say that I'm a Dominion guy now. YMMV. Pick a brake and be a d!ck about it. Don't forget that the best part of riding is the beer with friends afterwards :-)
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roil
1 year, 1 month ago
TRP vs Dominion. What's your take?
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Andrew Major
1 year, 1 month ago
Even compared to other DOT brakes I’m surprised how clean the fluid is every time I bleed the Dominions.
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Ripbro
1 year, 1 month ago
Chain reaction had a smoking deal on these last week. $170 CAD each end and a $50 off code on clearance items. If your in the states, 203mm d series rotors are $10 USD. My order total shipped was $384 CAD.
Haven’t ridden Hayes since their mag brakes. Looking forward to testing them out this summer. Go away snow…
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Andrew Major
1 year, 1 month ago
That’s a smoking deal. I’m certain you’ll love them but do feel encouraged to report back!
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Ripbro
1 year, 1 month ago
Will do. Can I use my old sram/avid bleed kit? Not sure if I need to get new fittings for my syringes. The ones in your pictures are much longer than mine.
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Andrew Major
1 year, 1 month ago
The Hayes fittings are different. If you can find just compatible fittings you could use an existing DOT bleed kit.
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Ripbro
1 year, 1 month ago
Thanks, I’ll order a new kit
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Andrew Major
1 year, 1 month ago
Their kit is of the particularly nice variety.
Ripbro
1 year, 1 month ago
I contacted Hayes about what fittings they use on their bleed kit to see if I could track some down.
They offered to send me some spare fittings in the mail.
A++ customer service so far.
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Andrew Major
1 year, 1 month ago
That’s cool! I guess who would ask for fittings that didn’t already buy their brakes? So it’s supporting someone who already supported them.
bishopsmike
1 year, 1 month ago
Thank you! Just ordered a set, came to $317 before duty! Wow!
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S Mears
1 year, 1 month ago
The A4's ended my search for brakes, period. Over the last few years they've been just as worry free as you say, Andrew. Same powerful, easy to modulate brake as day one. I do prefer the T100 over the T106 due to the immediate bite of the T100, but once the T106 was fully bedded in I didn't notice as much -if anything the muted bite can help to maintain traction when being ham-fisted with the brakes.
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Andrew Major
1 year, 1 month ago
Cheers! So you’re running the T106 front and rear? How do you find the life vs. T100 and versus other pads?
I could be talked into running the T106 again on the rear for the less grabby initial bite. Up front I like the power clap.
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S Mears
1 year, 1 month ago
Verdict is out on pad life, Andrew. I'm not a high mileage rider like y'all round here. As far as mixing front\rear that's a novel idea, and another way to tweak that balance aside from messing with the rotor size. I do a lot of simultaneous front\rear braking and getting similar response from front\rear does make the braking experience more balanced. Do it... why not!?
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Raymond Epstein
1 year, 1 month ago
I scored a set of A4’s last year after listening to the guys at my lbs and my best riding mate rave about them. In particular my pal decked out his monstrous S5 Kenevo and said if they could stop his galoot ass and that bike they’d be the brakes to beat. They felt great right outta the gate, but it was a long weekend at Snowshoe last year just prior to the UCI race that made me a convert. Like coastal BC, Snowshoe is always wet and steep AF. The brakes handled dozens of runs each day without a hitch. They howled nonstop, but never flinched and saved me from plenty of bad decisions. The noise was pretty bad though, but since I swapped in some MTX red pads they have remained silent. The only reason I could see anyone not liking them would be their weight, but that’s about it. I tell others that they have Saint power with Code modulation.
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JT
1 year, 1 month ago
This is the review I needed. Granted, it woulda been nice about 6 months ago before I bit the bullet on a diff brand, but still. I won't rant about my past experiences with the Big S companies' units, but I will rave about this review. If/When my current stoppers stop stopping predictably, the Doms have moved to the top of the replacement list. Sounds like a 'best warranty is one that doesn't need to be used' product, and that always earns high marks from me.
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Andrew Major
1 year, 1 month ago
The best warranty is the one you never need to use. It’s also very easy for companies to support product that require ~ No after sale support beyond bleed kits, rotors, and pads.
Apologies for the timing. I’ve had this in my head for a while but not quite six months, I swear! Haha. Always feel encouraged to reach out for a review update.
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jslaidlaw
1 year, 1 month ago
MTX red label pads for the win. They are relatively easy to bed in, have great power, exceptional modulation and are dead silent. They tend to last as long as most other pads I have run. As good as the original sintered, and even semi-metallic Hayes pads are, these have been a very worthwhile upgrade. I have three sets of dominions between my and my wife's bikes. I run the MTX pads on all of them.
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dolface
1 year, 1 month ago
Seconding this (and I wish they made them for the A2/T2s).
I just got some MTX Golds to try for the rear but my T106s haven't worn out yet (current set up is T106 rear/MTX Red front).
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SilentG
1 year, 1 month ago
If you were on a desert island (with hills and a mountain or two at least) for a year and had one bike with unlimited access to pads and maintenance supplies for bleeding for your brakes what would you go for between the A4, Magura MT7, Hope Tech 4 or Cura 4?
For myself, sans the desert island, I have several years on a Cura 4, a few months on MT7 in the past, and a couple of weeks on Tech 4 recently so I'm curious as to where folks would slot the Dominions given that none of those are exactly sad choices for a mountain bike so there isn't a winner or loser(s) just different gradients of pros and cons there.
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Andrew Major
1 year, 1 month ago
None of those systems give me pause. I’d be on the A4 only because my bike with them is feeling so dialled right now I’d just put a fresh 2.6” Purgatory on the back and 2.8” Vigilante on the front and go ride it.
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SilentG
1 year, 1 month ago
Right on!
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lennskii
1 year, 1 month ago
I've been on a few of those and agree that they all perform so well it comes down to a matter of preference.
You'd likely enjoy this fantastic comparison shootout from Blister.
https://blisterreview.com/gear-reviews/mtb-brake-shootout
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Vincent66
1 year, 1 month ago
Hi ! I’m curions here.
I have Ben riding with mt5 over the last 8 years, and was happy.
Tech4-V4 were on top of mylist for replacement.
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lennskii
1 year, 1 month ago
Andrew it's like the guys at Hayes read your recent articles on your love of purple ano and Dominion A4s...
https://www.jensonusa.com/Hayes-Ltd-Edition-Dominion-A4-Brake-Kit
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Andrew Major
1 year, 1 month ago
Hahaha. You wouldn’t believe how many folks sent me links to Purple Hayes today.
They do look rad. Too much purple?! Is there such a thing?!
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Briain
1 year, 1 month ago
Need to get a new set of brakes soon, I had more or less settled on the cura 4's but might look at these again
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Andrew Major
1 year, 1 month ago
Cura 4 is a great system. Simple, well priced, made in Italy, easy so work on, rebuildable and they use mineral oil which is easier to handle at home. They’re much prettier too.
The Formula brakes definitely feel more beaten and sloppy after years of use and I think beyond the so-nice lever feel and LOFI action the relative brand-new-ness of the Dominion after years of use is my favourite feature.
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Briain
1 year, 1 month ago
Ok, Good to know might swing my decision towards the Hayes brakes. I was wondering if you have any experience with the formula speed lock system was thinking of putting one on my rear brake as it'll be internally routed
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Andrew Major
1 year, 1 month ago
Yes, it works as advertised but doesn’t clear through all internal routing situations particularly, the male end is too long to navigate many tube-in-tube setups.
I have years on the same lines (I run them on my commuter now) first with Cura 2 caliper, then Cura 4 caliper, then Cura 2 again without any issues.
I was told Formula went away from them as a stock product because too many people couldn’t figure them out, resulting in leaks. if you’re curious there are close up shots in this teardown from 2018.
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Briain
1 year, 1 month ago
Thanks much appreciated. It's surprisingly hard to find much info on them. There's an old vid of a guy setting them up on a Tri bike with full internal handlebar/ stem routing. Just seems like a nicer way then a full bleed or leaking brake fluid inside a frame
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Briain
1 year, 1 month ago
You might have started a trend. I just ordered a set of the A4s. Now I'll go down my usual route of trying to get them to work with other branded things, hope rotors( should he easy but they fowl codes) and put a formula speed lock on the rear caliper and I'm good to go
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Kyle Dixon
1 year, 1 month ago
I have the A4's on 220/203mm Hope Floating Rotors and they work an absolute dream.
WalrusRider
1 year, 1 month ago
I'm very interested in this one. My Codes are dying and I've been looking hard at these Hayes or the new Hopes.
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Briain
1 year, 1 month ago
I've run a few sets of sram brakes and I've found all of the levels, guides, codes and code rsc all need a lever rebuild about once a year. Don't even need to replace the pistons but a clean and red rubber grease and their like new. It's a pain but cheaper then buying a new brake
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WalrusRider
1 year, 1 month ago
Can you rebuild the Code RS or R? I thought only the Code RSC is rebuildable.
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Briain
1 year, 1 month ago
Pretty straight forward
https://youtu.be/JwbcfYqyAK8
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Andrew Major
1 year, 1 month ago
All the SRAM brakes are fully serviceable. Even the cheapest Level-T and Guide-T brakes.
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Mike Rock Smith
1 year, 1 month ago
BIG plus 1 here for the Dominions as well. Been running the same set since 2019 as well with no bleed other than when I transferred them to a new frame (so only the rear brake was bled). Fantastic brakes. I biked up a value priced DH bike last year that has Shimano Zee brakes on it, and I'm basically being forced to buy another set of Dominions now. Jumping from the D's to the Zee's just does not jive.
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Andrew Major
1 year, 1 month ago
I know I'm not your mom, but it's time to give those fantastic, friendly, and reliable brakes the loving full-bleed that they deserve. They'll work even better with fresh fluid.
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[email protected]
1 year, 1 month ago
Hey there! I'm on my 3rd year now of A4's I bought from Bike24, 220mm rotors since day one here in Calgary. I had Saint's before and have ridden Code RSC's same time. The A4's party trick are the super light lever and progressive nature imho. The dual bleed ports and totally sweet grub-screw caliper alignment pieces are just icing on the cake! Mine had some paint blemishes though from new and one of the brake lines blew off on a down hill after a year, but I've been running DOT 3 (day 1 on the rear, 2nd year front, I have tons of DOT 3 for the work I do on cars) and even on some big park days (Kicking Horse) have never faded them. They have lots of power, perhaps not as much as saints, but the progression is superb. I'm on year 3 now of the stock sintered pads (never tried the semi-metallics) a ton of rides, tons, and they still have life on them, like you said, the pad life is superb! must be a slightly harder compound, or highly resistent to heat buildup, they last forever. I think from Germany, it was 450$ cad for the set, which felt like quite a leap considering I'd never tried them or knew anyone who even had them, but my friends are all following suit now after trying my bike and buying them. My one friend got them for his fat bike, we do lots of downhill on them, they're the best, and DOT means no cold weather issues like comes with Mineral brakes. I think they're pretty btw! check out my youtube review I did last year on them. https://www.youtube.com/watch?v=fzXZ_fNHn8s&ab_channel=Kingsoupturbo
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Alpenglow93
1 year, 1 month ago
Andrew, great article. I am about two years on mine. I love the dominions with two exceptions. I have a very hard time getting a good bleed on the rear brake and too much free stroke on the lever. Can you suggest any good bleed videos and tips to reduce free stroke? Thanks!
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ohio
1 year ago
I'm in the same boat. Using the Hayes bleed kit, following instructions. I'm able to get a rock solid bleed with a lot of effort (unbolting calipers and levers to get perfect gravity and straight hose help) and using both caliper ports, but as soon as I travel with the bike, it goes back to a spongey mess with levers to the bars. Has happened twice, and I don't remember ever having that issue with Code RSCs...
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tashi
1 year ago
Well this article convinced me to try something other than Shimanos for the first time since SRAM decided that (without me knowing) I’d be their beta tester for XO and Juicies, but now they’re getting hard to source! Lucked out and snagged the last one from CRC this morning, psyched to try out some non-disposables.
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Andrew Major
1 year ago
Be sure to post up once you have some rides on them!
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lennskii
10 months, 4 weeks ago
Pulled the trigger on some Dominion A4s after the comprehensive nuanced review/comparisons by Andrew. My favorite brake to date! Absolutely loving them. Some from-the-hip comparisons to brakes I've used for prospective A4 owners.
- Best lever feel (both dead stroke and through the bite point). Super light, super consistent and predictable. Power is among the best out there (perhaps slightly edged out by Trickstuff and Hope Tech 4). Easy to get a good bleed.
- vs. Shimano 4-pots just feel notchy now and the ramp in power is super spikey. No wandering bite point issue too.
- vs. Code RSCs, they're easier to bleed well and LoFi beats out the RSC Swinglink (don't need to rely on the Bite Adjust to compensate for the piston seals that don't cope with pad wear very well in the SRAM calipers). Can hit the "wall" of power easier when you want it vs. Codes, which oddly feel less "powerful" at the end stroke than the initial stroke/pull of the lever (suspect it's to do with the shape of their Swinglink).
- vs. Hope Tech 3s. One of my favorite aspects of their lever is the short dead stroke very close to Shimano. The Dominions are on part with the Hope's in that regard (great for my medium sized hands and someone who likes to run the levers close to the bar, 10-15mm from the bar, at full pull) they just do everything they do but better - more power, smoother lever. Less faff to bleed.
- vs. TRP Quadiems - was my ideal brake aside from the excessive increase in deadstroke when you run the brake closer to the bar and/or don't have large hands. Dominion peak power is easier to reach vs. TRPs which relies significantly on mechanical leverage, but the TRPs get there (unlike Hope Tech 3s) and do so in a controlled manner (unlike SRAM) in a predictable even manner (unlike Shimano) . TRP levers also develop slop over a year or two of use (just like the Cura levers). Doesn't appear to be an issue for the Dominions.
- vs. Magura MT5s - less vague bite pull. Magura's with their many levers would be the best option for those with very small hands and run the lever close to the bar. Power/lever feel/finish all top Magura. Magura bleed is one of the hardest to nail well vs. the others mentioned above.
Downsides? The levers are a little so-so in the aesthetic department. Finish is nice but nothing to write home about. On par with SRAM/Shim. Pads are also more expensive with less 3rd party quality options. Important to note that the calipers are quite large, so you'll need to use a Magura or Hope or Hayes brake adapter to allow for sufficient clearance. Pairing with Hayes rotors is ideal as they have a particularly wide friction band/braking surface. Spares have decent availability (replacement levers and caliper seals). Not up to the level of Hope, but better than Shimano, on par with SRAM and TRP for the lever only (TRP caliper aftermarket spares sucks).
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Andrew Major
10 months, 4 weeks ago
Cheers, if you think of it post back in a couple of years and let me know how they're still working out for you. Trying to measure products over longer periods of time.
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TristanC
1 year, 1 month ago
I've been curious about these for a while. I've only used Shimano and Tektro hydraulics before, so the idea of DOT is a little off-putting to me. In general, is it actually difficult to work with (toxicity, shelf life, etc.) vs. mineral oil? Or am I making a mountain out of a molehill?
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Graham Driedger
1 year, 1 month ago
Short answer: yes. Dot is fine to work with. Use proper PPE and keep a spray bottle of soapy water close by to clean off any dribs on your bike.
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JT
1 year, 1 month ago
Just as OSHA recommends wearing gloves with DOT, they also recommend the same with mineral oil. All the hype about toxicity is pretty much irrelevant and what I suspect to be an OE quibble to save paint jobs from sloppy assembly/bleeds. Plus side, DOT comes out of clothes. Can't say I've been that lucky with Shimano mineral oil regardless of what I've pretreated the spot with.
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Andrew Major
1 year, 1 month ago
DOT requires a little bit more a clean-room / clean-up mindset as it will absolutely eat paint. But not the way some folks fear. Just wipe things down with soapy water or ISO and make sure no fluid/spillage is sitting under you master cylinder clamps.
The worst part about DOT 4/5.1 fluid is that it’s hygroscopic so once you unseal a container, yes even with the lid on, it starts to go off. Again it’s not close to instantaneous, but that guy who sits on a big bottle of mineral oil at home using a little at a time over a decade isn’t going to be able to do the same.
Bonuses of DOT is it’s standardized, cheap, and available everywhere. I currently have three different mineral oil fluids at home.
As to toxicity, you wouldn’t drink mineral oil either and, as noted, the same PPE us recommended.
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Deniz Merdano
1 year, 1 month ago
For storing partially used bottles, either squeeze the bottle and then replace the cap, or get a bag of marbles from the dollar store and fill the bottle up until the fluid reaches the top. Should keep forever. Same also goes for sealant bottles.
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Pete Roggeman
1 year, 1 month ago
Bloody brilliant, Deniz. Get a few photos and let's add that to a 'hacks' article.
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Deniz Merdano
1 year, 1 month ago
A trick I picked up from my darkroom days. You have to store film development chemicals in full bottles or they expire.
Marbles also help with agitating the sealant sediment without foaming up.
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araz
1 year, 1 month ago
What's the effect of using old DOT fluid that has gone bad? Any way of determining if a bottle has turned and needs to be replaced?
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Andrew Major
1 year, 1 month ago
Most companies recommend using an opened bottle of DOT fluid within 12-months max. The issue is moisture content lowering boiling point.
Automotive shops test moisture content in brake fluid and 3% is the max permitted. I don’t know any bike shops that test moisture content.
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araz
1 year, 1 month ago
Is the lower boiling point actually noticeable in mtb use? Guess I’ll just get some new fluid before my next bleed anyway
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Andrew Major
1 year, 1 month ago
I have experienced and have heard many stories of brakes where brake levers can suddenly get spongey or worse be pulled straight to the bar. That’s from fluid boiling, or more accurately vapour from the boiling fluid being compressed.
So, yes it can happen on bikes.
There are multiple solutions - bigger rotors, different pad compounds, less brake dragging (not always an option depending on application - my cargo bike comes to mind) - but fresh brake fluid is an inexpensive way to keep brakes functioning ideally.
araz
1 year, 1 month ago
Thanks Andrew. Good to know. Appreciate the info.
Timer
1 year ago
Thats debatable. The fact that badly maintained mineral oil brakes are the de-facto standard in MTB gives hint that fluid boiling is probably no issue for most riders.
Because mineral oil can't absorb water, most mineral oil brakes slowly accumulate water at the lowest point in the system, the caliper. Which leaves the system with a boiling point of 100°C. From memory, even DOT 4 with a water content of ~10% still has a boiling point well above 100°C.
In terms of handling, i actually prefer DOT because it is so easy to clean of with water. If mineral oil leaks out anywhere near the brake assembly the effort to get everything properly and reliably degreased is much higher.
Andrew Major
1 year ago
@Timer we were talking about thus today at the shop, specifically how much easier it is to clean DOT fluid off brake rotors than n the event or a spill. Mineral oil has a lot of staying-around power.
JT
1 year, 1 month ago
If it's been open for longer than 6 months, recycle it, especially if it's stored in a high humidity environment. Had a couple folx have their brakes bled by a LBS years ago who ran into an issue when storing their bikes in sheds and cars with the brakes locking up. Issue at hand was possibly over filled, but the fluid was also old and saturated at greater than 4%. Turns out no one in the shop knew how long they had the bottle, which is never a good sign. Water's thermal expansion rate is considerably different than DOT, even at 'reasonable' temps. A hot car in the sun is just as bad for old brake fluid as it is for your pets. If you're as tool happy as I, you can pick up a DOT fluid tester that will tell you the moisture content of the fluid. They're relatively inexpensive. You can also get brake fluid test strips. Again, cheap and effective.
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Andrew Major
1 year, 1 month ago
Ahhhhh. I need another tool about as much as I need a second appendix but I’m also hungry to test some brake fluid. Haha.
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[email protected]
1 year, 1 month ago
Having dealt with dot fluid on motorbikes a lot I frickin hate it. Your paintwork will hate it too.
On an bicycle it's also completely unnecessary to spec dot IMHO.
What isn't that well publicised is that you can run mineral oil in dot brakes, without any mods.... IF they have never had any contact with dot fluid.
I am currently running a frankenstein setup using calipers from a brand designed only for dot.
So if you can get your desired brakes supplied dry you can put what you want in. If the seals can handle dot they can handle oil.
The swelling people talk about is when a seal that has been exposed to dot then gets exposed to oil.
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Andrew Major
1 year, 1 month ago
I’ve turned wrenches at home and in shops for a fair while and never had an issue with DOT and paint.
I’ve witnessed issues, but if you clean up spills with soapy water or ISO it doesn’t eat the finish?
Can’t comment on running mineral oil in DOT and DOT in mineral oil systems beyond seeing a few seized up systems from the wrong fluid. Interesting note re. starting dry.
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[email protected]
1 year, 1 month ago
Unless you act pretty quick on dot cleanup you get a paint issue.
Or you can use mineral oil and not worry about it at all. I just don't see what the benefit of dot is in a bicycle application.
Mineral oil keeps the caliper seals lubed too.
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Andrew Major
1 year, 1 month ago
I don't pretend to be an expert on brake fluids. What I like about DOT is it's standardized. What I like about mineral oil is it's easier to handle at home. Some of my favourite brakes to work on and ride use DOT fluid, so I work on them so I can ride them.
My understanding from talking to folks from a couple of brands that continue to use DOT in the face of the pressure to switch to mineral oil - particularly OE pressure, see SRAM DB8 - is that they get better results in brake testing and longevity from DOT fluid.
Hayes dabbled in mineral oil brakes (the Radar brake system) and stuck with DOT for the Dominion for the more consistent performance.
I suspect in their case that's particularly more consistent performance in the cold (they are based in Wisconsin and ride fat bikes). It doesn't get that cold here on the North Shore, but certainly DOT fluid brakes perform better when temperatures drop.
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[email protected]
1 year, 1 month ago
Good point, well made!
Doesn't get cold enough here to run into that issue.
Timer
1 year ago
With mineral oil in a bike brake setting, you have to be absolutely, 100% sure that not even the tiniest hint of oil is left anywhere near the disk or pad.
I actually worry quite a bit about a safety risk like that. Much more than i worry about paint damage on a bike that regularly gets used offroad.
With classic cars or motorbikes, priorities might be different.
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Briain
1 year ago
That's actually why I prefer DOT fluid it's much easier to clean. It also feels like brake cleaner does a better job on dot rather than mineral oil
Deniz Merdano
1 year, 1 month ago
My only issue with Hayes brakes jas been the lack of parts availability in the local postcode.
When a damaged brake hose or a lever ruins a ride, you are going to have a harder time sourcing parts locally.
Sure the online retailer can save the day but how long did Graham had to look around for when he needed a brake bleed and pads? This was of course couple of years ago.
I do love the lever feel of the dominions and wouldn't hesitate to run a set if it came to me at a decent price...
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Graham Driedger
1 year, 1 month ago
To be fair, I think I had a replacement line within a week. I think the distribution is out of Quebec, so shipping from there factors in for timely repairs.
I did, however, stock up on some spare parts for my toolbox, in case of unexpected repairs. We're so lucky to have quick access to parts for both Big S companies locally, it's an adjustment of expectations to run something funky and different.
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Mike Rock Smith
1 year, 1 month ago
I got a bleed kit across the street if you ever need!
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Graham Driedger
1 year, 1 month ago
Hey Mike, thanks! Let's get out for a ride again soon. I do have a bleed kit at my spot - so let's have a bleed party with some cold bevvies!
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Andrew Major
1 year, 1 month ago
Apart from ShiRAMano products any brake system requires waiting some period of time for spares. Even with ShiRAMano, it can be hard to find a stockist for many small parts since no shop wants to be stuck holding when stuff goes off.
The Dominions came out in 2019, so for a couple years in their existence no one was doing a great-great job of supporting product. Pretty hard to be too mad at Hayes when there was a year you couldn’t get a 12-spd chain or DUB bottom bracket. How long was Shimano out of any brake levers for any system?
S4 Suspension in Quebec is a stockist and they seem to do a decent job of having stuff and for an individual it’s easy enough to get parts from the USA as well. With all the good aftermarket pads now and DOT being standardized it’s just the bleed kit really.
———
On the lever comment - that is one advantage of going with bombproof stuff if it’s going to be rare/exotic. These really are as new.
On the brake line comment - I actually can’t remember the last time I replaced a brake line for someone who wrecked it in a crash. Cut too short, or cut when removing zip-ties is a different story.
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Deniz Merdano
1 year, 1 month ago
Great to hear availability has improved since I last checked. I have similar concerns for the TRP brakes aswell. Lie 2 play never stocks any parts for them.
As for brake line damage due to crash is quite common on our shores. Accidental zip tie issue however is a new one for me ..
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Andy Eunson
1 year, 1 month ago
S4 bought Melius here in Whistler. I don’t know what they have for brake systems but they have a fair bit of stock for forks and shocks.
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Andrew Major
1 year, 1 month ago
I always forget that! Thanks. I'm sure they'll be supporting Dominion brakes out of Whistler then. The fluid being something standard you can get anywhere, it's not a big deal to carry pads and then a couple lines and bleed kits.
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XXX_er
1 year, 1 month ago
these sound OK, back in the day the old Hayes Mags weren't really all that powerful and i had multiple hose failures
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Pete Roggeman
1 year, 1 month ago
Back then, Hyundais also sucked and most companies wouldn't use Apple computers for anyone but graphic designers.
That was a long time ago.
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Andrew Major
1 year, 1 month ago
I rode a couple generations of Hayes Mags (master cylinder changes), Grimeca four pistons, early Formulas, Coda brakes (shudders) and Shimano XT four pistons (M755) and I would have give the edge to the Hayes brakes until Avid came out with the Juicy 7 and Shimano came out with XT M760.
Jeff and I were going to fully rebuild a set of purple Hays Mags with NOS guts and pick up fresh aftermarket pads for a proper comparison of past and present but the old brakes we picked up were just too rotten. Either way, I think it’s safe to conclude from the budget to boutique the good brake systems today are significantly better than the good brake systems of the late 90s and early noughties.
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The Dominion A4s are excellent.
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Ripbro
1 year, 1 month ago
I remember Hayes made a cable actuated hydraulic brake. They were one of the OGs
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Andrew Major
1 year, 1 month ago
Those were so awful... I mean, just like every other 'cable-actuated-hydraulic' system to come out since then. Awful to work on, awful to use.
They actually came out just after that first champagne coloured brakes as an effort to hit lower price points, so it also didn't help that they shipped with crappy v-brake levers v. nice ones. One of those pay more now or pay A LOT more later products where many owners ended up scrapping them to buy the real deal. I haven't actually seen a set on a bike in years and years.
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Pete Roggeman
1 year, 1 month ago
I had a set that came stock on an orange Brodie Evolution, which was one of the first hardtails you could get with disc brakes - this was 1998. I couldn't afford a Brodie Holes hot which came with the hydraulic Mags. Those cable pull Hayes were so bad they had to be bled after every single ride and I was riding 4-5 times a week - or wanted to be. I was taking the bike back to West Point for help almost every day. Eventually Bruce Spicer (still working at Brodie!) took pity on me (or on the poor folks at WP trying to help me out) and hand-delivered a set of Hayes Mags for me, FOC. Amazing service. Those hydro's were problem free for a long time. That bike was awesome after that. Wish I still had it.
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Andrew Major
1 year, 1 month ago
I believe Bruce Spicer owns (a share of) Brodie now? They still have a great customer service reputation.
That’s awesome that Brodie & WP got you sorted. Many riders were not so lucky.
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araz
1 year, 1 month ago
A few small issues I've had with my A4s that I've been using for 2+ years --
The rear brake develops a periodic creak at the lever in the little ball/cup joint. Goes away if take off the lever and clean everything out in there, but seems to come back every couple of months.
Weirdly, the seals on the lever bearings deteriorated and fell off. Bearings were still fine, but I had them replaced. Wish that I could have found the measurement for the bearings somewhere, but my shop was able to figure it out.
Had some noise/resonance from the rear brake. Lubing the pistons and going to MTX pads has taken care of it.
Overall great and super consistent brakes. Got them on some kind of promotional special where I paid something like $350 US for the set with rotors.
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Andrew Major
1 year, 1 month ago
I’d suggest the bearing seal issue is most likely some DOT fluid that didn’t get cleaned up. Only because I’ve seen it on a SRAM brake with the finish peeling such that that was clearly the cause and haven’t seen it otherwise.
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danimaniac
1 year, 1 month ago
this sound?
https://www.youtube.com/watch?v=WsbIHdHAQKM
cured with a drop of MucOff Dry Lube ;-)
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glib
1 year ago
I have exactly that sound and the dregs of a bottle of muc off dry. Where do I aim it exactly?
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lennskii
1 year, 1 month ago
Timely article, have always (and continue) to enjoy your articles Andrew for how genuine and littered with nuanced insights they are.
I've just pulled the trigger on some A4s after reading your write-ups. Have ridden new/older Shimano 2/4pots, SRAM Guides/Codes, TRP Quadiems, Hope Tech3 e4s and Magura MT5s.
Favorite of the bunch were the Hope E4s, primarily for a somewhat linear bite, ease of setup/bleed (used playing cards to center the rotor to the caliper), consistency of bite over the life of pad wear and particularly the short-ish lever throw before bite (a delicate balance with the reach dial as I have size M hands + like to run the bar decently close to the bar). Main downside is their power.
The Dominion A4s seem to tick all these boxes with much more power than the Tech3 E4s (so I don't have to resort to running 220mm F&R rotors + Galfer Greens only anymore...) except the short lever throw. Heard it's a little longer (like the TRPs) which is OK, but gets worse as the pads wear. Do you have any tips to reduce this?
The standard forum trawl reveals some have done a mini-lever bleed (a la Shimano) as the pads wear (as the Dominions, like many brakes, seem to increase their throw with pad wear despite the supposed fixed seal rollback in the calipers). Any legitimacy to this?
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Andrew Major
1 year, 1 month ago
I don’t need to lever bleed the A4s over a set of pads but I ain’t claim that they (or any other set of brakes) don’t have a slight variation in throw as the pistons are resting out further in the caliper.
I suspect most issues with lever bleeds being required on brakes come down to there not being enough fluid in the master cylinder when the pads are fresh.
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lennskii
1 year, 1 month ago
Thanks for the response Andrew. Will be sure to be meticulous with the bleed/follow the Hayes procedure to a tee. 🤙🏽
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Joseph Crabtree
1 year, 1 month ago
This comment has been removed.
Vincent66
1 year, 1 month ago
Anybody had a chance to compare A4 with Hope tech4-V4 ?
They seem to be really good to !
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Kyle Dixon
1 year, 1 month ago
Personally No, but the owner of my LBS remarked after trying them out on my Tyee "How mad are you gonna be if my Tech4's are on here when you get it back"
Sample size of 1 of course but apparently he liked the feel...
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lennskii
1 year, 1 month ago
Semi-direct comparison that may be of interest.
https://blisterreview.com/gear-reviews/mtb-brake-shootout
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[email protected]
1 week, 6 days ago
I am planning to get a set of A4 to put on my Arrival 170. I currently have SRAM HS2 rotors (200 and 220). Do you think these will work fine with the Domininons or is it worth getting the D Series rotors?
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lennskii
1 week, 6 days ago
I have a mate who switched from SRAM Codes using HS2 rotors and they work with the Dominions no issues (the differernce is 0.05mm, which is tiny - same difference between a standard SRAM and Shimano rotor).
The D-Series rotors do have a slighty wider braking band though, but as far as I can tell the Dominion pads (which are quite tall) make full contact with a HS2 rotor.
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