So I was doing some tinkering on my Rockshox Revelation team forks today and was tinkering with the settings of the gate on the blackbox. After a while I was failing to notice any difference so I fully locked the gate and compressed the fork- it was as easy as if the compression control was turned off.

So any idea what I have done and whether I can fix it myself- I’m off for a riding weekend next weekend so don’t have time to get them serviced. Is a oil leak the most likely cause or have I broken something internally?
Cheers

“was tinkering with the settings of the gate”
here is your problem, turn it the other way

no thats my point, no matter which way I turned it I couldn’t get any noticeable difference

Quite possible that your rebound cartridge has been quietly emptying it’s contents into the lower leg, check for signs of oil at the bottom of the fork, and check that you’re able to get full travel.

As far as I can tell I get full travel, is there anything else I could look at from the outside to help diagnose the problem? If the rebound cartridge has slowly been draining oil, is it simply a case of topping it up or is it the sign of a full service being required?

Let all the air out and compress them to see if you get full travel, the oil level in the damper unit may have just been a bit low.

ok will try that, if the oil level is a bit low do I have to top it up with specific fork oil?

Ok so I removed all the air from both chambers and get 125mm of the supposed 150mm of travel. THat strongly points to the oil leaking into the lowers right?

yes, minimum, seal head seal replacement (spacer with internal and external seals on that divides the damper chamber from lowers with the rebound rod running through it)
Or full seal replacement in damper leg (full moco kit)
Or Full service.

Brilliant, just what I want to hear on a fork thats less than a year old. What would be the most likely cause? riding to much like a big heavy lump and being front heavy?

If they’re less than a year old they’re still under warranty, get them back to the original supplier to sort, hard to say on cause, dodgy seal on rebound rod part of seal head possibly or dirt ingress to the lowers getting onto the seal and wearing it from the oi in the lowers 😕

Ok now I’m thoroughly confused. I’ve just dismantled my forks, removed the black box and rebound damper and my inspection of the rebound damper is that there is no sign of damage or wear and the oil removed from black box chamber was over 100ml plus some that was lost on removal. What on earth is going on?

http://www.sram.com/_media/pdf/rockshox/dealers/2011-Revelation-Technical-Manual.pdf

The blackbox damping system has 133ml in, if a small has got past the seal head into the lowers it will cause a hydraulic lock reducing the travel, SRAM say 3 to 8 ml in each of the lower legs so even a relativly small amount may cause a reduction in travel.

If you’re really stuck put them back together and get them back for warranty repair.