Interbike 2011: Fox’s dropper post moves closer to launch

Plus first ride impressions of new 29er-specific F34 fork

The Fox Racing Shox booth was getting a lot of interest at this year’s Interbike show, with their new DOSS (Drop On Steep Stuff) height-adjustable seatpost drawing lots of attention. It’s been a year since we stumbled across the prototype at Interbike 2010. Things have progressed since then but there are still some development to go until it hits shops in 2013.

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The new twin tab remote lever can be set in four different positions on the bar; above or below, on the right or left. Push the smaller of the two tabs and the post will only drop to the first position, which is 60mm from fully extended. Hit the larger of the two tabs and it can be dropped by 60mm or the full 100-125mm, depending on which length post you have. Both levers will then bring it back up to full extension.

Fox doss height adjustable seatpost:
Robin Weaver
The current twin tab remote lever of Fox’s DOSS dropper seatpost prototype

This dual-position system has been developed based on feedback from Fox’s sponsored racers, who wanted to be able to engage only the 60mm drop when clambering to lower the saddle in the heat of the moment, with no chance of accidentally triggering the full drop.

We have to admit we prefer the Fox prototype post on US racer Adam Craig’s bike, which uses a Shimano XTR shifter to actuate it. It’s simple yet effective and maybe the way forward if you’re running 1×10. While the prototype version of the DOSS may use a slightly complicated, clunky lever system right now, we reckon Fox will have things dialled come 2013.

Fox F34 fork series

Also courting a lot of attention was the all-new 34 fork family, specific to the 29in wheel size. The bigger diameter 34mm stanchions and a new deeper, central grooved arch profile are designed to combat the problems of excess twist and twang at the end of unavoidably long fork legs. The forks were fitted to a couple of bikes at the Interbike Dirt Demo (Yeti’s new SB-66 29er and Salsa’s new Horsethief) and we’ve had a TALAS version on test back in the UK for a little while now.

At 2,099g with a tapered steerer, it’s 246g heavier than an F29 TALAS cut to the same length, which is a substantial increase. However, the difference in stiffness, particularly tracking accuracy, is phenomenal. Radiating root spreads can be cut as close to the trunk as your bars allow and off-camber slopes carved across with confidence. The extra 20mm of travel and improved fore-aft stiffness mean deep-drop, slow-speed steps, normally off the menu on big-wheeled bikes because of twist under braking, are the staple diet of the 34.

Fox f34: fox f34
Guy Kesteven

Fox F34 fork

FIT compression damping is as controlled as ever and Kashima coating, plus new SKF seals, means excellent small bump and rebound sensitivity. Being able to flick the fork back to 110mm is very useful for steep technical climbing, particularly as 29ers designed for over 100mm of travel are very rare. We’ve been running it at full stretch everywhere else though, with our test team equating the experience to their first ride on Fox 36 forks compared to the 32 series.

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While the upgrade in multi dimensional control from the 34 is dramatic, it’ll be interesting to see if Fox move their 140-150mm forks onto a similarly upsized chassis. The increase in stiffness would be gratefully received by those who find the current carcass too twangy – particularly in 150mm format. However, if weight increases are similar, a 34mm 26in-wheel fork would be treading on the toes of the existing 36 in terms of mass.