Castellano flat-plate stay re-worked, revived in Ti Cycles mountain bike
If they're good enough for F1 cars, flat-plate pivotless suspension arms should be okay for cycling. Ti-Cycles, as ever looking to incorporate clever thinking into its designs, approached the esteemed engineer John Castellano to adapt his Flat-Plate chainstay for 3" tyres.
Flat-plate, or flex-plate, chainstays were popular in the 1990s when rear suspension travelled less than now. The obvious advantage is the absence of chainstay pivot bearings, which wear out after a while leading to rear-end play. But the safe movement range of flat plate stays was up to about 60mm, and the market demanded more travel, so it was back to tubes and pivots.
Craig Calfee has been using the idea for several years with his suspended carbon fiber road and gravel frames, and not long ago, Dave Levy of Ti Cycles had the idea to redesign Castellano's flat-plate stay around the larger tyres that are now standard on off-road bikes. He approached cycle engineering genius John Castellano with the idea.
In this video Levy and Castellano talk about the process and challenges designing the renewed flat-plate stay, as well as durability and the how the bike rides.
This video is also available on HBG's YouTube channel, Bike Artisans. Here