The RP series from Fox has been a benchmark in air shock performance for some years now, so we were eager to see if small shims and the benefits of huge knowledge could make a great damper even better.
That’s where PUSH Industries come in – they’ve been tuning shocks and forks, and producing suspension upgrade components, since 2003. They’ve also been linked with UK suspension tuning gurus TF Tuned Shox since 2004.
In-house PUSH specialist Dave Whitemore has unrivalled experience in custom-valved PUSH upgrades. He stripped and serviced our RP2 shock as well in the price, including replacing all seals and O-rings as a matter of course. But the magic was in the shim stack construction.
We told Dave exactly what we wanted from the shock – to get rid of that wallow you get as you push into a bermed corner or load up the suspension to initiate a bunnyhop. Small bump performance was a priority, yet we still required a decent pedalling platform for stonking our way up climbs.
It turns out that Dave is like Neo from The Matrix, except rather than seeing in binary, he sees in shims! Armed with our performance wishlist, bike type and weight, he got to work. He fitted an initial shim stack, which could ‘flutter’ to allow plush initial small bump movement, giving traction on climbs and on smoother trails.
A secondary shim stack came into play for when bump forces increase, giving a smooth transition into proportionally increasing compression damping to resist wallowing under rider input load. We bolted the shock to our trusty Cannondale RZ140 and were instantly impressed.
Small bump sensitivity was noticeably increased over the pre-PUSHed shock. The load-proportional damping worked wonders for resisting travel-eating wallow too. The bike didn’t have that tendency to blow through the travel when railing high-load corners and was far more stable hitting compressions too.
We found that we had to adjust our ride settings to suit. We only needed the ProPedal platform damping to be engaged for in-saddle steep climbs, where weight was biased to the rear. Everywhere else, we left it disengaged, because the bike sat up in its travel much better, so it didn’t need the platform to sit on.
This gave us increased traction, while retaining efficiency. Air pressure was also reduced, giving us about five percent more sag, since the shock didn’t need the extra pressure to resist wallowing. We got what we asked for, and since it cost us just £50 more than a standard service, we reckon PUSH is the way forward.