Dial in your Reba like a pro!
Success! After almost 2 years of owning my RockShox Reba fork I was finally able to get it dialed in to be smooth as butter yet nice and responsive.
It’s not like I’ve been living with a terrible fork all this time; quite the opposite. Rather, I was riding a bit of a mystery. See, I picked up the Reba 2 years ago as a late season clearance item at a majorly reduced price. Upon installation I quickly realised that there was a problem with the negative air chamber losing all pressure after being inflated. No problem, the LBS sent it back to Lambert (the disti here in Canada) and took care of everything. Since the internals needed to be swapped out they also offered to set it up special just for me. When I got the fork back it was absolutely amazing, except for the fact that no one along the way remembered to document how they had it setup. With the fork running so smoothly and not wanting to lose anymore time off the bike I never bothered to investigate or mess around for fear of wrecking my custom setup.
Fast forward a year and a half. Ultimately, air valves bleed off slowly and the fork needed some attention. Enter the frustration. In this case, RockShox seems to have incorrectly labelled the base air pressures for the positive and negative chambers. If you were to follow the guidelines, you inevitably ended up with a fork that was not much fun to ride and did not come anywhere close to using all of it’s available travel. Measuring the sag at only 5% (rather than 20%) was not a good sign. This might not sound like a big deal to setup, but considering you have to deal with both the positive and negative air chamber, as well as the compression rate, rebound, and the flood gate there are almost infinite possibilities for tuning the Reba. Infinite possibilities equals some rather annoying levels of confusion.
After a load of research and reading, I finally found the right formula. Since you’re dealing with a negative and positive air chamber that work together it made sense that there would be an air pressure ratio at work here. I was absolutely correct. First off, the positive chamber does the majority of the work and absorbs the big hits due to it’s larger air volume. On the flip side, the negative chamber is used to absorb all the small hits and literally gets the fork moving early in it’s travel and requires a smaller volume of air. Now, if you put 60% of your body weight into the positive chamber and 10lbs less than that in the negative chamber you should be set. In my case I weigh approx 185ish with all my gear on. Knowing that, I put 110lbs of air pressure in the positive chamber and about 100lbs in the negative chamber (as opposed to the 140lbs suggested by RockShox). I knew that was the right mix as soon as I measured the sag at a perfect 20% of my total available travel. With that setup I left the compression dial all the way open, the rebound just shy of full fast, and the flood gate at 2 turns towards the closed position.
Now for the trail test. All I can say is this setup yields pure butter. I was initially worried about brake dive and bottoming out with the lower than recommended pressures, but within minutes my concerns were erased. Thanks to my handy zip tie on the fork arm I could instantly see I was getting full use of my travel. Hitting really rooty and stuttery terrain rewarded me with vastly improved handling. Rolling drops with lots of compression felt as if I had endless amounts of travel and not a single feeling of bottoming out. The only thing I did notice was that I needed to turn the compression dial closed slightly before hitting drops with lots of g-force in order to stiffen it up ever so slightly. Considering drops like that are rare, this is an absolutely acceptable compromise for me.
So, if you too are riding a Reba (or a Revelation, or a Pike) the 60% body weight positive pressure and 60% minus 10lbs in the negative chamber should serve you well. Once you’ve got that dialed in all you need are a few pounds more or less based on the terrain you’re riding. Enjoy!
I have had my Rev 426 for almost 3 months. I have been trying to get the ideal setting which should enable me to go both uphill and downhill with ease. Having played with the setting for almost 10 weeks, I have finally come to this conclusion. I set the travel at max travel, rebound damping 3 clicks from full fast, compression set at mid-way, floodgate at mid-way. About the pressure, positive set at 55% of your bodyweight with gear and additional 10psi for negative (better sag). Try this…
right, i had loads of trouble getting my rebas to work right. with the recommended settings way too much sag and never reaching full compression either, so only about 1″ useful travel.
anyway, I wanted to share this for any other very light riders (around 60kg!) and this blog seems a good place
let all air out of negative, then positive. turn damper full to fast. check fork compresses nearly all the way in (if not, probably too much oil).
pump positive to about 7bar/90psi.
flip bike upside down and pump in just enough negative to stop the fork topping out (may take a few attempts because the -ve capacity is tiny and any escaping air when removing pump messes things up). for that’s about 5-6 bar probably.
ok.. this is less +ve and way less negative air than recommended but none of the “10psi less than +ve” stuff was working.
finally, lower the floodgate so it’s just enough to stop bounce when out of saddle. and raise the damping again (not much).
adjust by making very small changes to +ve air.
works for me, and probably any other very light riders. or i just have a weird fork.
thanks for allowing the above – i realise it goes against your OP a bit sorry.
the basic problem i think is that guides all talk about pressures, when what really matters is the amount of air in each chamber.
unless you have a perfectly frictionless system (in zero gravity too!) pressures don’t tell you much. you have to do it by feel really..