I’m servicing my 2014 SIDs for the first time and finding an issue with the air shaft not moving the whole way up the tube.
Can’t attach photos for some reason so this is an album.
https://photos.app.goo.gl/2rHa6csfwkUdQKQWA
the shaft physically will not move further than this (top cap is off). The service picture in the manual shows the silver sleeve almost next to the red cap so something is wrong.
At a loss to figure out how to fix it. I have been having trouble getting full travel and this is likely the reason. Anyone got a bright idea?
I’m now kicking myself for not buying in the UK as they would have to go back to BikeInn for warranty. Figured as I was comfortable doing my own spannering I could fix things myself.
You have negative pressure in the air piston, I had exactly the same with my SID last week. Remove top cap in full, remove circlip with pliers, thread the fixing bolt back on the bottom of the leg. Then wrap a cloth around the bolt and pull really really hard, there will be a load pop and the air piston will come out (the noise is you overcoming the negative suction pressure). The SID has an equalization dimple on the inside of the stanchion (allows positive pressure to equalize between the upper and lower), it's likely the dimple has become blocked with grease. Clean and degrease inside the stanchion, then very lightly grease the rubber seals and push the air piston back into the fork and refit the circlip.
I’m servicing my 2014 SIDs for the first time and finding an issue with the air shaft not moving the whole way up the tube.
Can’t attach photos for some reason so this is an album.
https://photos.app.goo.gl/2rHa6csfwkUdQKQWA
the shaft physically will not move further than this (top cap is off). The service picture in the manual shows the silver sleeve almost next to the red cap so something is wrong.
At a loss to figure out how to fix it. I have been having trouble getting full travel and this is likely the reason. Anyone got a bright idea?
I’m now kicking myself for not buying in the UK as they would have to go back to BikeInn for warranty. Figured as I was comfortable doing my own spannering I could fix things myself.
Hiya,
Rather than pulling excessively and potentially damaging o rings etc (or flying across the room), you can put the cap back on (and circlip).... inflate the positive air chamber until the shaft no longer gets longer.... and just pull on the shaft. You should hear a hiss/squish. That's it equalising.
Drop a bit of pressure in the positive chamber (slowly)... and pull on the shaft again. Keep doing that until you know it's ready to come out.
Hi, sorry wasn’t clear. I’ve had the whole shaft out and the red cap off. It’s not the negative air spring
If you look at the other photos in the album one of them shows how far the shaft will go in with the negative air spring red cover off.
The only thing I can think is the tube gets narrower nearer the top?
seems odd.
Can you put the jounce bumper jounce bumper (rubber thingy and plastic thingy) on it? There needs to be room for both of those to contact the red cap when you bottom out. The whole shaft won't go into the chamber in normal use with that in the way.
Measure 120mm on the shaft itself (from the top out bumper/spring). The shaft will definitely be longer than 120mm to accommodate the jounce bumper (rubber thingy and plastic thingy).
But if you're worried, and authorized service centre can check the fork for you. If it's not in spec, they will sent it to SRAM for replacement (unless SRAM authorizes a repair instead).
So it doesn't need to go back to the retailer - book a lower leg service at an authorized service centre and they can check it when it's apart. That's what I did with mine. In the end, I wasn't charged for a service because they could tell straight away that it needed replacing.
PS Is the valve stem out/removed? Just wondering whether air pressure is stopping the shaft from moving any further.
The stanchions can't/don't taper, that would never work on a fork. When you put the air piston back in the red metal tab should be pushed up to the underside of the black rubber seals and near to the grey/white piston head, this would leave the lower leg section almost the same length as the damper side. Once inflated the negative chambre opens up, when the fork is equalized.
The stanchions can't/don't taper, that would never work on a fork. When you put the air piston back in the red metal tab should be pushed up to the underside of the black rubber seals and near to the grey/white piston head, this would leave the lower leg section almost the same length as the damper side. Once inflated the negative chambre opens up, when the fork is equalized.
His is the newer SID with the Debonair+ air spring - the problem being is that the service manual suggests pushing the piston all the way in, to avoid scratching the air spring shaft when putting the circlip back - which is where the OP got stuck.
If the valve stem has been removed, it would be a bit odd. Hmmm.
Anyway - just a bit of spare hosepipe will do. The shaft just needs to be protected from scratches.
Like this (from the Rockshox SID service manual)
Like this (from the Rockshox SID service manual)
Once again, the fork the OP's trying to service is a different model (I think 2014 was a typo). The recommended assembly process delineated below (to avoid scratching the shaft):
3">2024+ SID SL SID Service ManualSRAM https://www.sram.com › front-suspension › 2024...
Either there's a problem with the stanchion & airspring (warranty to the rescue)... or it's simply a bit of air pressure that's difficult to overcome (hence asking if the valve core has been removed).
Correct on it being the new one that the service manual says to push all the way in. Hosepipe is a great idea, thanks!
Top air cap has been removed and it definitely physically stops when it gets that far in. I’ve still to measure with the bump stops etc.
I’ve been thinking it might narrow at the top due to the interference fit of the legs into the crown. I’m maybe just trying to get it to move past where it would in normal use.
it’s in bits at the moment will get another look at it tomorrow night. Thanks for the suggestions.
Is the airshaft too long? If your fork is 100mm (guessing) then could it be a 120mm airshaft?
When I've changed airshafts to increase travel, I recall they have a code on them.
Sorry, put it together late last night and had a quick spin this morning.
All seems to be in spec. Looks like I was trying to push the shaft in too far. The hosepipe was a great recommendation. Particularly as the red cap was difficult to push all the way home and the hosepipe made it easy.
So answer is I was looking for a problem that wasn’t there. By the time you added the jounce bumper and the plastic spacer the shaft moved properly.
Thanks for all the help and I recommend the hosepipe method.
