EDIT: it's a coil fork and the bike is getting sold in a month so not getting a new fork.
Alright suspension nerds I need some thoughts on this.
I have a Transition TR500 with a 2016 Rockshox Boxxer RC.
May 14: Fork Recieves a full service and new seals in Spain.
June 8: After 5 days of riding at a bikepark in Austria, the damper side dust wiper slides up the leg and leaks oil everywhere.
June 9: Fork receives another 50 hour lower leg service with new seals in Switzerland.
June 17: after 4 days of riding at another bikepark, the same issue happens.
On the 17th, I noticed that the fork was bottoming out often and feeling super harsh on the big/quick hits throughout the day.
It's in a shop getting ANOTHER 50 hour service currently, as tomorrow (June 18) I'm going to another bikepark where I only have 3 days to ride.
So, what could be causing this? Could the fork legs be messed up? Do I need to glue in the seals?
PS. The photos are from both times it happened. (Despite looking identical)
by C0deC4tto
13 Comments
Am besten kaufst ne Oehlins Gabel.
Are they using the right seal kit?
Looks like the seal popped out, you can slide it down and reseat it with the fork assembled, but if it popped during a ride day I’d just do a fork service and clean everything/reseat it. Make sure you have the correct oil volume in the lowers when you reassemble; I’ve seen this when there’s too much oil making the air volume smaller and thus higher pressure faster when the fork compresses.
Three thoughts
1) clean the face the seal sits against, do not use grease to install seals
2) try a different seal brand
3) replace the lower
I’m interested to see what others say but given it’s the damper side we can rule out a leaky air spring.
Unusual for the seal to pop out repeatedly like that. Makes me wonder if there could possibly be a casting issue in the lowers. If you’ve ever had to remove wiper seals (or seat them), they’re in there pretty good. There is no way they should randomly slide up like that.
Clearly the seals don’t fit securely in the lower assembly. Maybe replacing just that would solve your problem. I would reach out to RockShox o for advice or warranty inquiry.
Takes 50 hours to service a fork? Pardon my ignorance
I’ve only had this happen when my air spring was leaking into the lowers, but this is the damper so there goes that.
I can’t claim to know the geography of all the places this bike has been (I’m jealous btw), but it could be building up pressure from changing elevation and temps. I don’t think this fork has bleeders, so you can use a super tiny zip tie or cut a chunk out of a plastic pop/water bottle and carefully shove the corner down the wiper to see if there is any trapped pressure in there.
It’s weird it’s only happening to the same side, could be the inner diameter is the top of spec or over spec, they may also be letting some oil get in the seal air. Usually wouldn’t be a big deal but maybe try getting it as clean and oil free as possible and shoving it back in there.
If all else failed, I wouldn’t think twice about putting a small thin layer of silicone or something like that to “glue” it in. But I’m a redneck.
Leaking damper fill lower leg so pressures increase to a point that seals pop out? Weirdest thing is that shop you serviced it didnt bother to look out for defects
Looks like the front fell off.
It could be that the shop is installing the oil soaked foam rings first which is contaminating the interface between the lowers and the seals. I would try cleaning the mating surfaces with IPA, re-installing the seals, and then installing the oil soaked foam rings last. It also wouldn’t hurt to put some suspension grease on the inside of seals before installing the uppers for a little extra lubrication. It might be that the heat and friction from hard bike park riding is causing the seals to pop.
Fork lowers are cast magnesium. Magnesium gets brittle and deforms as it gets used.
From my experience with failing magnesium pedals, magnesium slowly sags/changes shape before it cracks.
Considering your fork is 10 years old and had 4 owners, I would say this is symptomatic of a fork that is slowly failing in the best possible way. I have only had seals do this around the 2 or 3 year mark, and a new seal kit has always lasted another 2 or 3 years agter that (its hot and humid here, 3 years is the longest wiper seals last me).
Maybe lose bushings?