Initial impressions: The first thing we noticed was how easily it slides into its travel. The shock on our Saracen Ariel test bike probably cost more than one of the beater cars in the background of this photo. Being happier going down hills, rather than up them, we set the shock with about one-third sag, and pretty fast on the rebound. Most of that time it’s been out in big, alpine terrain with 1000-meter descents. In that time we’ve put it through what our cigarette-packet math adds up to well over a hundred hours out on the trail, which is getting towards a years’ riding for an “average” rider (although what’s average, right?). We’ve had the RP23 shock attached to a 140mm Saracen Ariel since August 2011. For example when you reach the end of the stroke, even if the shock is moving relatively slowly, a huge chunk of compression damping kicks in to prevent an abrupt bottom-out. Working off of the preset pressure of the shock's internal floating piston, the Boost Valve meters the compression damping throughout the stroke, making the damping action position-sensitive, not just speed-sensitive like other shocks. The Boost Valve is the feature that Fox is most proud of. This latest version is the product of constant development and you’ll find all the features from the last few years like the larger volume air can (XV chamber) to help the shock feel less progressive (so it ramps up less aggressively at the end of the stroke) and a Boost Valve. Inside the shock: Inside there are enough features to keep even the nerdiest rider happy. The new position diagram is really welcome While we would have liked to see more tuning info on the Fox website, Fox's Race Program Manager sheds some light on the tuning options available: Buy the wrong one you’re going to have to send it to them to get it re-tuned anyway. In fact, there are several hundred variations you can get, so to find the best one for your particular suspension design and and riding style, it’s best to ask the professionals and get them to help you select the right tune. We went for medium tunes on the compression and rebound, and 175psi in the Boost Valve. Get the right tune: If you are thinking about buying a Factory-Series RP23 aftermarket, we would advise strongly that you buy it from a proper Fox supplier, as there are different tunes available for the boost valve, XV sleeve, compression and rebound damping, and ProPedal.
The redesign gives the RP23 damper a wider range of tuning options without the complication and added weight of a piggyback-reservoir type damper. Adaptive Logic's low-speed compression adjustments control ride-height and mid-stroke suspension action. The compression adjustment controls the shock when the ProPedal lever is switched to 'open.' Turn the two-position lever to 'ProPedal and you get super firm pedaling that is preset internally. Here you can see how different the 2012 rebound adjust is (on the left)Īdaptive Logic: For 2012, fox has re-worked the adjustment on the ProPedal and re-named it 'Adaptive Logic.' You still get three options for the little dial on top of the lever, but now they are numbered '0', '1' and '2' and it sets the shock's low-speed compression damping. The XV air-volume boost sleeve is not coated because it has no moving parts Because the parts are immersed to receive the special coating, the outside of the air can gets coated too. A quick call to Fox Racing Shox, and they explained that both the shaft and the inside the air can have a Kashima coating as there are seals sliding on each surface. Kashima coated parts are sent to Japan where the patented (and expensive) process is applied, so we wondered why it looks like the coating was on the outside of the air cannister too. 'Gold' and 'Shiny.' Those words are music to the ears of bike tarts everywhere and for our money, this is the best-looking shock out there.
Straight out of the box, you can’t help noticing the RP23's low-friction Kashima coating.
Boost Valve position-sensitive compression damping Adaptive Logic three-position compression adjustment Kashima low-friction coating on shock body and internal shaft