I have spent the past few months engaging the big wheel revolution after moving from the dual suspension 26" Specialized Epic onto the Specialized Stumpjumper Hardtail 29. It's kind of just like riding a bike; a bike with bigger wheels, and a bike without the rear suspension that I have been accustomed to over the last few years.
Out of the box it was obvious that the handle bars were too wide for me so 20mm came off each end. To establish the riding position on the bike Pete dug into his BG Fit files to draw from the recent setup of my road bike using this to replicate some base settings. We set the saddle position, skinned the tyres of the tubes in favour of a tubeless setup and ventured out onto the trails.
The bike change meant I adopted 2x10 gearing. So far the combination of big wheels and gearing has been excellent through the many and varying trails and terrain I have encountered. The XTR rear derailleur uses a tension switch to increase the spring tension against the chain. This reduces the chance of a dropped chain over choppy terrain, which has returned plenty of proof of its function as I've popped out of some rough descents at Stromlo, Mt Buller and the You Yangs to hit the pedals with the drive line all ready to go. It also reduces the amount of chain slap on the frame's chain stay. The initial thought of less gear choices overall makes you wonder where the gaps will open up in the range, will it leave fewer gears to climb that long, punishing track or will there be a jump between a couple of gears that feels like the no-man's land of a gear that's too easy and a gear that's too heavy? If anything it leans toward the easier zone as the response from the bike whenever I stand on the pedals is amazing.
The carbon fibre wheels keep the weight down and help the bike's responsive acceleration. And do these wheels roll?! The 29" wheels do their part in maintaining base speed, one of the findings with 29" wheels is how they hold speed when I back off the pedals, comparing to the way 26" wheels seem to surge and drop speed when pedalling then backing off. Point the bike at some rough, randomly cobbled, rock paths and it is impressive how the bigger wheels soak up the variation across the technical aspects. This takes effect in both descents and climbs, if you can keep cranking the pedals the bike will continue to scramble up, over and through what lies ahead. Letting the bike accelerate with gravity returns an incredibly rapid rise in speed. The XTR brakes have got everything under control if the speed gets to be too much, though.
The hard tail plays its part in the responsive performance of the bike. Coupled with the SID Brain Fork it makes for a punchy climbing machine that is more than ready for technical descents. The front wheel is kept on the ground with the SID Brain fork, a fork that Rockshox has developed with Specialized. The Brain Fork is always active and returns to a more rigid effect on smooth terrain. Tuning the fork pressure to suit my riding style has been worth taking the time. I started with the recommended settings and worked from there, taking further advice from a couple of riders that excel at bike setup and tuning. Using the tell-tale o-ring on the fork stanchion I varied the air pressures until 90-95% of the fork travel was being used during known, worst case, rocky descents and the performance has been great. Although there is only 90mm travel this has been adequate once I got the fork pressure right.
Technique is a major contributor to how fast and smooth the bike can perform. Tuning my riding to how the bike handles has been my biggest focus, and to me is an ongoing thing with mountain biking in general. The main variables of the bike are tyre choice and pressure, and with these combinations matched really make the 29" Stumpjumper Hardtail an effective weapon on the trails.
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