Spotted: Prototype FMB Cyclocross Tubular Tire With TPU Tube, Instead of Latex Inside

In an otherwise unassuming corner of the Tábor World Cup Cyclo-Cross pits, fitted to a nice celeste, purple & blue Bianchi, we spotted a new prototype FMB tubular tire that appears to have a TPU tube inside. Why that might matter, and whether TPU will be coming for latex in elite cyclocross racing, deserves a bit more explanation.

But suffice it to say that tubeless dominance has seen the evolution of tubular tires grind almost to a halt. Maybe handmade French tire maker FMB has some new ideas up their sleeves… inside of their sew-ups!

FMB World Cup Cotton+ Sprint 2 TPU prototype CX tubular

As a quick explainer/refresher: Tubular tires generally are constructed of a lightweight fabric casing (often polyester, cotton, or silk) sewn shut over a relatively conventional inner tube, with a rubber tread then glued on top. In the end, you glue the whole thing directly to a smooth rim bed without bead hooks. The conventional wisdom has been that this makes for lightweight, suppleness, and low rolling-resistance at high pressures on smooth surfaces, i.e. track racing. But it also really benefits cyclocross at extremely low pressures with incredible sensitivity and grip, reduced pinch flats, and a lower chance of the tire separating from the rim in extreme cornering or off-camber riding at those low pressures. But almost all tubulars use a latex tube inside, which isn’t the lightest option, not always the lowest rolling resistance, and loses air pressure over time.

So, FMB decided to try TPU tubes inside, instead.

In fact, FMB has already experimented with German-made Eclipse ultralight TPU tubes in their fastest track tubulars for more than two years, claiming weight savings, improved air retention, and greater durability. And they aren’t the only ones. Vittoria makes a TPU version of their top-tier Pista Oro track tubular as well, also touting a reduction in weight and rolling resistance.

So could those same high-pressure benefits transfer to low-pressure cyclocross tubulars, too?

It looks like FMB is testing that hypothesis on the World Cup to know for sure.

FM-Boyaux.cc