Trek’s Jeremy Horgan-Kobelski toed to the line of the US Pro XCT series opener at Bonelli Park in San Dimas, California this past weekend on a new 29er fork from RockShox. Despite the 'Reba' decals, the feature set looked more in line with RockShox’s 2011 model year SID.
When RockShox designed the long-travel version of the venerable cross-country fork they took considerable effort — in the form of FEA analysis and structural engineering — to bolster the platform’s strength and stiffness without adding weight. We expect much of the new 29er fork’s design comes directly from the SID120 platform.
Trek were tight lipped — even secretive — regarding details or allowing photos of the new fork. However, its defining features jump out and can be directly compared to SID120: a clean, integrated hydraulic brake line attachment and refined lower leg architecture complete with scalloped Power Bulges, SID-like ‘brake’ bridge and 15mm Maxle through-axle.
Jeremy Horgan-Kobelski was spotted on a new 29er fork from RockShox this past weekend
A through-axle on a lightweight race fork? RockShox made considerable headway with their 2011 forks in this department. Their quick-release 15mm axle now weighs just 71g and, along with redesigned lowers, the complete package adds just 100g to the 26er fork.
RockShox wouldn’t confirm any details of the new fork. “We test in the field with our athletes for a reason — because it gives us the best feedback,” said Tyler Morland, SRAM’s mountain bike PR manager. “We’re going to have a great showing at the Taipei show. We’re not going to delve into detail but it'll be a strong showing; another strong presence and offering from us.” Taiwan's Taipei Cycle show starts tomorrow (15 March) and runs through 19 March.
The upper tubes of the new fork, along with the crown and steerer, appear to be alloy. Again, the crown architecture looks to be much more in line with SID’s design than Reba. The steerer is also, likely, tapered, as Horgan-Kobelski’s 2011 Trek SuperFly features an e2 tapered head tube. The prospect of a carbon fibre crown should be mentioned, as Horgan-Kobelski and others were seen testing BlackBox labeled Reba forks in 2010 with this feature.
The crown of a 'BlackBox' Reba fork JHK rode in 2010
Internal changes could include the use of RockShox’s drilled bushings, a weight saving design introduced with the 2011 SID redesign. When the fork finally goes into production we'll expect to see the uber-light Keronite Grey finish (also introduced in 2011), which is said to drop 20g compared to a standard powder coat finish.
The damper technology is unknown at this point. However, it can be assumed to be new, due to the fact that Horgan-Kobelski is riding with a fork mounted damper adjuster; the rider has seldom been seen without a handlebar mounted lockout in close to a decade.
Putting all of this together leads us to believe the new fork will weigh around 1,500g (with carbon crown and Keronite Grey finish, based on similar 120mm SID models). Considering the lightest 2011 Reba model is claimed at over 1,700g this will be a compelling option for cross-country racers whose discipline is becoming overrun with big-wheeled bikes.