One ingredient not mentioned by Mike-the-Man nor any commenters:
Kevlar.
About 20-24 years ago, the GEAX brand advertised (IIRC) “3D Compound” which had randomly-oriented Kevlar fibres included in the tread rubber.
AFAIK: GEAX was a sub-brand of Hutchinson or Vittoria and didn’t last long.
I never tried a GEAX tire. However I did work as a labourer in the DuPont Canada production line at Kingston, ON — that compounded raw Kevlar into rubber nuggets.
Those nuggets (looked like fig newtons after extruding as a ribbon and then cut to length) were sold to various mfr’s to be mixed into their products at the molten rubber stage.
Adding Kevlar strengthens soft-compound rubber. Thus: grippy tread AND longer life.
I’m guessing it will influence hysteresis as well. Positively? Negatively?
I never see any evidence that contemporary high-end bicycle tire mfr’s are incorporating chopped fibres of Kevlar into their tread compounds.
If I were manufacturing tires with Kevlar (as above), I might not advertise that fact. I might let my tires’ performance speak for the secret ingredient(s).
Someone with a microscope who knows what to look for could probably detect such fibres in the tread compound.
The longevity of my MaxTerra DHF rear tires amaze me. The knobs can look Über ragged yet never has one torn off.
April 12, 2024, 1:41 p.m. - Larrabee
One ingredient not mentioned by Mike-the-Man nor any commenters: Kevlar. About 20-24 years ago, the GEAX brand advertised (IIRC) “3D Compound” which had randomly-oriented Kevlar fibres included in the tread rubber. AFAIK: GEAX was a sub-brand of Hutchinson or Vittoria and didn’t last long. I never tried a GEAX tire. However I did work as a labourer in the DuPont Canada production line at Kingston, ON — that compounded raw Kevlar into rubber nuggets. Those nuggets (looked like fig newtons after extruding as a ribbon and then cut to length) were sold to various mfr’s to be mixed into their products at the molten rubber stage. Adding Kevlar strengthens soft-compound rubber. Thus: grippy tread AND longer life. I’m guessing it will influence hysteresis as well. Positively? Negatively? I never see any evidence that contemporary high-end bicycle tire mfr’s are incorporating chopped fibres of Kevlar into their tread compounds. If I were manufacturing tires with Kevlar (as above), I might not advertise that fact. I might let my tires’ performance speak for the secret ingredient(s). Someone with a microscope who knows what to look for could probably detect such fibres in the tread compound. The longevity of my MaxTerra DHF rear tires amaze me. The knobs can look Über ragged yet never has one torn off.