Fair Wheel Bikes Part 2 – Crumpton 29er Evolves, Gets Sequential Di2 Shifting & More
First shown at NAHBS earlier this year, Fair Wheel Bikes’ Crumpton 29er project has come a long way, baby.
Originally spec’d with a full SRAM XX group, all traces of a mechanical shifting group are gone in favor of an automatically sequential shifting system custom programmed by their wizards (we hear its some of the same people that code for Apple). Notice any triggers or buttons up there?
Few items other than the frame remain from the original build.
From a distance, the one-sided carbon rigid fork grabs the eye first. This is one of about eight or nine ever made. Wheels are comprised of some trick prototype Tune hubs, Pillar ti spokes and ENVE rims with Geax handmade tubulars.
Shifting is handled by custom thumb buttons built into Ashima lever clamps, one button for up and one for down located on left and right brake clamps. Shifting is sequential, choosing the next best gear among 14 available distinct combinations. But it’s smart. Rather than just go up and down until it needs to shift in the front, a computer inside the stem knows where the chain is on the cassette and keeps it in the same front chainring until the gear ratios warrant a change, then it adjusts both simultaneously to move the gearing progressively harder or easier. On top of all that, they changed the shift timing to make it a little quicker than stock Di2.
Think this is hot? They’re working on a wireless version…
KCNC’s new spider web chainrings, also used on the sub-11 pound road bike they showed off.
Rear Tune hub is a prototype version with three or four paired rare earth magnets that push the drive rings together, so there are no springs. The magnets are tiny, so they save weight over having multiple springs. It’s loud but super light at just 99.3g on their scale at the show. On the left pic, the drive ring is literally floating inside the hub shell. On the right, the small silver circle just barely visible on the inside right edge is one of the magnets. There’s a corresponding magnet in the drive ring that’s flipped to oppose (push against) it.
The saddle stays the same (Tune), but they swapped in a red KCNC Ti Pro 8000 Lite seatpost (scandium tube, alloy head and ti bolts). The headset is a new, possibly prototype KCNC titanium DLC headset with ti retainers with DLC coated races. It’s almost $400.
Some of the chatter around the booth was that Fair Wheel Bikes actually added about two pounds back to this bike to put it at 14lbs because “people would give us too much crap if we brought a 12lb mountain bike to the show.” Not an exact quote, but the point is, this bike is stupid light. Price was undisclosed, but it appears to be an ongoing project as the wires running to/from the shift buttons were taped to the bottom of the handlebar and the downtube…not the usual elegance we see from FWB.