Wider stance compatible with new 27.5+ tyres headlines the changes on Fox revised trail fork


The new Fox 34 will be fully compatible with the raft of new plus size tyres set to hit the market this year. 650b+, or 27.5+, uses, on average, 2.8in tyres for a semi-fat bike contact patch and greater compliance. The larger outside diameter is close to 29in, so can be run in 29in frames, as long as there is sufficient clearance.

The revised Fox 34 fork spreads its legs to accomodate the new 110mm wide-flange hub spacing (currently forks use 100mm spacing), but still uses a 15mm QR axle. Moving the caliper post mount, too, calls for a whole new hub rather than spacers letting spacers fill the gap. But that does mean you get a stiffer wheel, because the flanges move out and the spoke angle increases.

There’s also a fourth generation of FIT cartidge damper and new Float air spring, although no details were supplied with the press release explaining the precise changes. Upto 3.25in tyres can be accomodated, travel range is 110-150mm and the fork comes with a massive 51mm offset. Which suggests to us that it won’t work very well with regular 650b wheels, because the trail measurement will be reduced and make for very twitchy steering.

The industry is rife with talk of this new tyre size, so expect lots of new products to be launched this summer compatible with 650b+. Will it actually be beneficial? Is it just another wheel size when most of us are still trying to recover from the switch to 29in and 650b? At the moment we  have many more questions than answers, but time will tell.