28 July 2010

bikefix Initial Review: RockShox Revelation Team Air U-Turn suspension fork

Despite seemingly being headed for 'also ran' status as recently as 5 years ago, RockShox are back and earning more and more respect with each model introduction. As part of the SRAM empire, the brand has some serious engineering and manufacturing weight behind it- and it shows. Despite loving virtually everything about the previous generation Revelation 426, that fork was eventually retired. For the sake of variety, I spent some time on Magura's Menja and Marzocchi's 44 Micro Ti- both of which have excellent small bump action- and Fox's '09 32 TALAS- which doesn't. Still, princess that I am, I found faults with all three and decided to try the second generation 2010 Revelation Team.

I have to think that much of my fork pickiness is due to my light weight. Part of the reason that I often return to RockShox forks, and recommend them to smaller riders, is the company's use of dual, opposing air springs. At 140lb, I'm well below the average rider weight that those suspension companies base their fixed negative springs' specifications on. Adjustable negative springs, on the other hand, allow a good deal of tuning flexibility. The idea is that the two springs push against one another and reach an equilibrium somewhere near the top of travel. Think about a spring pushing a weight against a hard stop. It takes a bit to get it to move against the spring, doesn't it? Now, picture the same weight suspended between two opposing springs. You can imagine that it would move much more freely than the first weight, right? Being adjustable, the negative spring can allow the rider to run more air pressure (for a more progressive feel) yet balance that with a higher negative spring pressure, which maintains small bump sensitivity. Want a more linear feel? Less positive pressure, less negative pressure. Want to feel all race-y and move only on big bumps? More positive pressure, less negative.

The second generation Revelation range gets a redesigned chassis (though still around 32mm stantions), complete with Power Bulge'd lowers. At 3.8lb, my Revelation weighs just about the same as my 120mm Reba with its remote lockout. Not bad at all. The lowers are available in 9mm (QR), 20mm thru axle and (for 2011) 15QR standards. It seems as though my own reluctance to adopt the 20mm standard has paid off as with RockShox on board we'll have a more common XC- and trail-oriented thru axle to play with. Until that becomes available, I've gone with the 9mm version. I've heard comments from larger, more aggressive riders than myself that the current Revelation's chassis is impressively rigid. Using a DT RWS 9mm thru axle, I can't say that I've noticed any flex or objectionable fore-aft movement- nor should I at my weight. The Team differentiates itself from lesser Revelations through the use of RockShox's BlackBox Motion Control damper, which sports separate high- and low-speed rebound circuits, a titanium spring, and "just dead sexy" carbon fiber lockout knob.

This particular fork uses Rock Shox's Air U-Turn travel adjustment system, a simple wingnut atop the left leg that winds the travel between 150 and 120mm. On my 5in trail bike, I tend to leave the fork wound in 4-5 half-turns, or at ~135mm. That leaves me in a good place for most climbing and descending. For longer, rougher descents, I'll wind it out to 150mm or down towards 120 for that raked cog railway feel. Air U-Turn seems to have disappeared from the Revelation range for 2011, which is a shame. It just seems that when going to a 150/120mm 2-Step travel adjust, it seems like some versatility is lost- and from what I hear, a good deal of complexity is added.

Back to the present, though. When set up with matching positive and negative spring pressures in accordance with the sticker on the left leg, the new Revelation delivers performance on par with its predecessor. Racers will be appalled by the amount of movement allowed by suspension unhindered by platform dampers or excessive low-speed compression damping. That said, on both low speed climbs and hairy high speed descents, the Revelation conforms to the trail like few other forks. The relatively high pressures (90psi in my case, vs 45-60 with Fox, Magura and Marzocchi) don't cause the stiction that might be expected and help the spring to ramp up as travel approaches its end, preventing bottoming on all but the worst line choices. The traction that small bump sensitivity provides isn't only beneficial on fast descents, but also on long rides, where fatigue is reduced, and loose climbs, where less effort is needed to hold a line. Good form can help to keep bobbing under control, but climbs are best approached seated, with a relatively high cadence. Repeat after me: spin and win.

Initially, I have to say that was a bit disappointed with the new Revelation's suspension performance. Over the past 5 months' riding, I've decided that coming off the incredibly plush Marzocchi's 44 made the boxfresh Rock Shox feel a bit harsh by comparison. With dozens of hours of use freeing up the seals, however, the fork feels much better than it did when new. While it can't compete with the 'Zoke's convincing hovercraft impression, the Revelation is still one of the best small bump forks I've ridden. I do have to wonder if the less-complex damper on Race level forks would be a bit more active than the Team's BlackBox version. Though a U-Turn Race was listed in RockShox's 2010 literature, I've never been able to find it listed by any of the major distributors.

No product is without flaws, though, and my Revelation's seems to be leaky negative air seals. Every few rides or couple of weeks, the fork loses a good deal of its small bump sensitivity. Re-pressurizing the negative spring reliably makes the fork feel much better- but it's a pain (and I'm someone who usually carries a shock pump). To be fair, I haven't tried to get the problem warrantied, and am sure that RockShox would either know a quick fix or send out warranty parts quickly (SRAM is a favorite among bike shops for their warranty policies). Because the BlackBox damper doesn't feel quite as active as my Revelation 426's, I'm thinking that a change to more weight-appropriate 2.5wt oil might be in order.

All in all, the Revelation Team remains my favorite trail fork. The new chassis is stiffer than previous versions, and the additional 20mm of travel comes without any weight penalty. The price is a bit high at $705, but that seems to be a result of only selling aftermarket U-Turn Air forks in Team trim- I haven't noticed any real benefit to the BlackBox damper and would suggest that riders looking for a fixed-travel fork start there and put the $200 saved away for a rainy day. With 2-Step forks already becoming available and 2010 forks being discounted, now might be the time for anyone looking for an adjustable-travel trail fork to buy. For trail and enduro riding, I still haven't found a fork that I'd rather ride.




Anonymous said...

Think you'll ever consider getting your fork "Pushed"? How do you feel about aftermarket suspension tuning?

bikefix said...

That's a good question. I don't know much about Push in particular- beyond that they're a well-known Fox fettler- but do think that aftermarket suspension tuning has its place. Still, I know that few riders go that route and can't help but think that a $700 (or $900) fork should work well out of the box. Choosing the right fork for your riding and riding style will go a long ways...