Possibly the most fabulous bike we’ve seen at the Lenzerheide pits this week is that piloted by Bernard Kerr. Pivot Factory Racing is developing a new Phoenix Downhill Bike using a lugged carbon frame design to aid in rapid prototyping.
Sadly, the production frame will materialize in a more traditional carbon frame format and, realistically, no paint job is going to match how bling this thing is.
Moving on to arguably more important aspects… Bernard’s ride sees an all-new Dave Weagle linkage design that leaves the twin-link configuration found on the production Phoenix well behind.
The prototype gets a familiar-looking top rocker that drives the shock but, lower down, things are far more intricate.
From what we can see, two links connect the chainstay to the front triangle in a layout reminiscent of the DW6 platform. The chainstay’s lug actually has two pivots, one connecting to the higher link that pivots about the seat stay, and another that connects to an even shorter link that again, pivots about the seat stay.
I can’t quite do the mental gymnastics necessary to see exactly how these links will articulate, but it’s clear from the high main pivot location that this bike will deliver a rearward axle path.
As with any high-pivot design, this one necessitates an idler pulley to route the chain in a kinematic-friendly manner. Clearly, Pivot has taken a less conventional approach to this with a Jackshaft style twin-chain solution, wherein both chains are on the same side.
The chainring drives a very short chain, that in turn drives a pulley wheel that is pivotally connected to a secondary chainring that drives the main chain… which drives the 10 speed cassette. The drivetrain solution, also patented by Dave Weagle, was previously covered in detail by PinkBike’s Seb Stott.
Ultimately, this drivetrain layout allows the team to spec a much smaller chainring than usual (26T or 28T, maybe) to give the bike more ground clearance. It also has next-level chain wrap everywhere, reducing the chances of a dropped chain to nigh-on zero.