Suntour Epicon Fork - Negative Air Suck Issue

vulva65

Hi Guys,

Okay so I rode BPW at the weekend and at lunch I realised my arms were killing me and after checking my forks (standard on Giant Trance 4 2015, Suntour Epicon TR RL-L) I realised that the 140mm travel was down to 100mm with no weight on the bike, I sat on it and the stanchions pretty much disappeared! I went to see the BPW workshop and the guy said it looked to be a negative air build up and said they it would need to go and be serviced, he said a quick fix would be to put 90-100 psi in it, which I did, and then carried on riding, but they were horrible to ride and my wrists were killing me!

The bike was in for a service last month and has been riding fine up until this weekend so I don't really want to take it back in already as it's a nightmare to get it in and might not get it back for few weeks. I had a quick look on here and found a post saying about a similar problem on some Rockshox forks, the guy unscrewed the top left valve, released all air so the stanchions sank, then removed a bolt from bottom left of fork and released valve to let oil out, then replaced bolt and pumped back up to standard pressure and was sorted. This all sounds as if it might be too easy to fix the problem and if it were that easy then surely the bike tech at BPW would have just quickly done this and I'd be on my way.

My question is, would this method sort the problem for me, or am I best just forking out (pardon the pun!) for another service??

Any advice would be great, and please dumb it down for me as I have little (none) fork knowledge.

Cheers guys!

cooldad

I doubt they serviced the fork in a 'routine' service, which is generally a waste of time and money anyway (just fettle stuff as necessary).

Try letting all the air out, pump up and down a few times to equalise the pressure and see what happens when you pump them up again.

Or have the forks serviced or Google it and DIY. It's pretty simple, they are solo air so just really a case of letting the air and oil out, removing the lowers, clean or replace the wiper seals and foam rings and inside the legs, replace correct amount and weight of oil and slide lowers back on.

Don't just remove the oil, or you'll trash them, it's there for a reason.

vulva65

cooldad wrote:

I doubt they serviced the fork in a 'routine' service, which is generally a waste of time and money anyway (just fettle stuff as necessary).

Try letting all the air out, pump up and down a few times to equalise the pressure and see what happens when you pump them up again.

Or have the forks serviced or Google it and DIY. It's pretty simple, they are solo air so just really a case of letting the air and oil out, removing the lowers, clean or replace the wiper seals and foam rings and inside the legs, replace correct amount and weight of oil and slide lowers back on.

Don't just remove the oil, or you'll trash them, it's there for a reason.

Thanks bud, I'll try and give that a go, hopefully letting the air out and equalising the pressure will do the job, but if not I'll get researching.

Thanks again!