We had been hearing rumors of a new Trek full-suspension XC bike even before the new Top Fuel was revealed earlier this week. But while the Top Fuel got longer travel, a new short travel XC race bike also appears to be in the mix. We spotted it this weekend at the Nové Město World Cup, being raced by ex-world champ Jolanda Neff and a number of her Trek Factory Racing teammates…
Trek Supercaliber (?) prototype short travel carbon XC bike
So with the Top Fuel now a 115mm travel 29er XC, marathon & trail bike (and interestingly not seen at the World Cup at all in its new, longer travel form), what will this new bike offer? Trek already has the Procaliber softail design with IsoSpeed frame flex, but this new bike is something quite different.
Trek is obviously still trying to keep this new bike (I’m just going to call it a Supercaliber for now) under wraps, quite literally wrapping up the unique suspension setup under the toptube. It isn’t entirely obvious what is going on under there, but from a number of visible details and some rumors floating around, we can make a number of assumptions.
Is it a softail? Or is it a true full-suspension bike?
Also, almost every Trek athlete not riding this prototype at the Czech round of the World Cup is riding a full-suspension bike, for the notoriously technical course. One more reason to surmise that Trek’s top mountain bikers have proper rear wheel travel on offer.
The bike’s main suspension pivot sits above & in front of the bottom bracket, looking to share almost the exact location as the new Top Fuel. With tall, boxy chainstays that likely means a similar single-pivot rear axle path just like that bike, relying on seatstay flex to drive whatever shock is under that cover.
We can see with the rear wheel removed that the bike offers almost direct rear brake routing inside of the front triangle – although this looks like it could be a hole drilled just for the team mechanics. The factory team bikes are all built up with XX1 AXS eTap so there’s no need for shift routing. But the new frame includes a locking cable port that exits the base of the seattube, most likely for the standard rear brake setup & a rear derailleur that routs into an unused opening on the underside of the driveside chainstay.
The design of this prototype XC race bike has a one-piece rear end as far as can be seen uncovered. Each thin, flattened seatstay loops around the dropout to form the chainstay, then extends past the main pivot, looping around the seattube to the other side. Presumably these seatstays which do not touch the seattube, can then join together under the toptube.
What’s under that cover?
So what really is under that cover? Three items can clearly be seen that suggest it is a rear suspension damper, even if it isn’t a conventional air shock like we see on regular full-suspension bikes.
One, the Schrader valve poking out is an obvious nod to an air spring hidden somewhere under cover, conforming that there is a shock body hidden.
Two, there appears to be a black dial protruding inline with the suspected shock location, suggesting some user adjustability. And if developed with RockShox (or even Fox), that little red dial suggests rebound damping control, confirming hydraulic damping.
Three, the cable end sticking out is most definitely a rear shock lockout, suggesting enough rear wheel travel that riders will want to lock the rear end for climbs or sprints. Two cables coming from the left side of the handlebar in the complete bike photo in the workstand above confirm that a single lever locks out both fork & shock (no dropper cable thanks to AXS.) That together with the technical Nove Mesto course suggests this bike would likely offer at least 80-100mm of rear wheel travel.
It doesn’t look like there is room for a full-size shock under that cover (unless it is very compactly integrated into a cutout in the frame). So we suspect that Trek has partnered with a suspension maker (likely RockShox, due to the race team’s strong SRAM link) to create a customized, lightweight solution.
Neff’s bike is fitted with an MRP chainguide, but it appears to be mounted around the BB shell, rather than connected to a direct mount.
The new bike is quite clearly ready to race, it even looks like they have a production barcode serial number on the bottom bracket. Surely the Trek Factory Racing team has the new Top Fuel available to them as they are already popping up at retail. So the team clearly sees a competitive advantage racing the new bike now (whether weight or suspension performance), vs. waiting for Trek to release the bike publicly.
We anticipate getting more detail on the new full-suspension XC race bike any day now…