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Orbea Occam 2020 M10 stock
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Discussion Starter · #1 ·
Hello everyone,

got myself a new fork (not new since the fork is made in 2007, but not used) for my bike, a Recon 351 Solo Air 2007 with 130mm of travel, and the fork works superb - the rebound is working and the compression also, so everything is probably ok with amount of oil in the damper leg.

What bothers me, is that after putting air in the fork, the fork stanchions are 136mm long (L measurement on the picture; from top dust seal to the crown). A side note - when there is no air in left leg, and when I compress the fork to it's limits, there's a ~6mm distance from the dust seal to the crown (Lc on the pic). Conclusion form the side note is, that the fork is really a 130mm travel, which leads to my problem.



After pumping air in (lets say 125psi; but it really doesn't matter, the problems is still there if I put 100-90psi), and getting full travel (136mm stanchions length), the fork is somehow in a "lockout mode", and it doesn't compress. I've put the quotation marks, cause the compression knob is full open (counterclockwise). And I know that 125psi is a lot of air, but that simply isn't it. Something is blocking the fork.

After applying more force on the fork, the "lockout" thing "breaks" and the fork works like a charm and I can compress it with my hands on the bar (little, but it can be compressed without a problem), but now the stanchions are only 126-128mm out in full travel, and not 136mm like in the first place (before the "lockout" barrier). So I lost round 8-10mm of usable travel.

What could be the problem for that "lockout" barrier which disappears after the first compression, but takes my travel ? It happens every time I pump my fork.
As I said, the fork isn't used, but it's a 2007 year fork (bought it from my LBS).

I could not find a similar problem with a RS Recon in this section (tried search but most of the problems with Recon are hydrolocks). Thanks in advance for all the help :).
 

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This essential issue comes up almost weekely here.

You have a 3 year old fork that uses VERY small volumes of oil in places to lubricate things like the bushings and the o-ring that seal the air chamber.

There is so little oil even when properly filled, that sitting for three years could have allowed the oil to solidify and not do its job.

My strong suspicion is that a full lubrication oil check (and possible o-ring replacement) will get your fork running properly.

all the tech info as well as lubrication types and volumes as well as ho-to videos are all at SRAM.

SRAM.com -> Service -> Recon
 

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Discussion Starter · #3 · (Edited)
Davep thanks for the reply. I have all the tech data (service guides, spare parts pdf, user manuals) and have experience in RS forks, cause I serviced some of them (but they were always coil spings). Still, I'm not sure that the o-rings or oil is the problem here, cause the fork works very well after the first compression.

I even found a post here in the forums, that Recon 2007 has floodgate settings (something like Reba SL), which I wasn't aware that Recon had. Nonetheless, some thing is blocking the last ~10mm of travel, and it isn't oil in the damping leg (hydrlock).

But I'll take your advice and check the fork, but I was just trying to get an opinion on what to look first ;).

EDIT:
Pumped the fork again (after getting all the the air out), got it again to 136mm, still with "lockout" in the first place, and when you compress it to brake the "lockout" barrier, you can hear a sound of the air moving in the left leg and the travel shortens. So, probably a valve problem that lets more air to the negative side and it swallows the travel.
 

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I would first try to just add a little oil to the air piston. The oil in the air piston helps the seals to seal. It'll only take you a couple of minutes and you might get lucky. If not, you need to service it.
Coincidentally, my UPS guy just dropped off a new 2008 Recon 351 Air on my porch today. There are good deals to be had on new old forks. I think I've only purchased one fork that was the current model year.
 

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Yea, not functioning corrrectly in some manner. As the fork compresses, the pos chamber pressure becomes higher and the neg champer pressure drops (possibly a vacuum). It is pretty easy to understand how air would migrate from the high pressure to low pressure either through the equalization valve, or the o-ring on the pos air piston., and this would to a loss of travel.

The valve is supposed to re-ballance the two chambers at 'top-out' each and every stroke, maintaining the proper negative/positive pressure ratio even if there is a small migration on air with something like a harsh bottom out. Each and every stroke should result in auto-correction or the pos/neg chamber pressures.

A leaking and/or sticky valve could certainly lead to increasing negative pressure and loss of travel.
 

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Discussion Starter · #7 · (Edited)
I didn't open up the fork yet, cause I couldn't find any 5W fork oil (I would like to change the oil since the forks hasn't been ridden in 3 years) but I thought of something that I could do in the meantime, that could point out the cause of the problem.

Pumped the fork so the legs are in their full length, remembered the pressure (120psi) and when I pushed the fork trough the "lockout problem", lost the ~10mm travel and also, lost 10-15psi of pressure in the positive chamber (110-105psi). So now I'm sure that there is a problem with the equalization valve or, like davep said - or the o-ring on the pos air piston. Most probably the equalization valve.

Now I know that everything would be better if I opened the fork, but I would like to do the job right at once.

@ Trailville
Most of the problems with the rebound o-ring getting broken and hydrolocking the fork was in Recons from 2008, so be careful ;).
 

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Vuco said:
@ Trailville
Most of the problems with the rebound o-ring getting broken and hydrolocking the fork was in Recons from 2008, so be careful ;).
Thanks, but i'm not too concerned. O-rings are easy enough to replace.

I still say you should try putting a little oil in the air chamber though. Not that I'm confident it will fix your problem, but it may fix it and it's very easy to do.
 

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Discussion Starter · #9 ·
Hello guys,

today I found some time service my fork and change the oil inside. The odd travel loss is still there after the service, but I got my full travel (130mm). There was a 10mm spacer inside, which I removed.

Now when I pump the fork from 0 psi, to let say 100 psi, the length of the stanchions is 145mm, then when the fork is compressed for the first time the positive air chamber looses 10psi, and the length of the fork legs outside of the lowers is round 135mm, which is what it needs to be. :)

Eye inspection of all the parts showed no sign of any problems or defects. I also putted ~4cc of oil in the air chamber, so it covers the seal/piston.

I'm happy that now I have my full travel, new oil, and the truth is that I don't care for that air loss (10psi) when the fork is compressed for the first time. :)

Thanks every one for their help.
 
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