Are my forks, forked ? ( Update,I found the problem)

[outerlimits]

RS reba’s, 2018 solo air.
Forks get sucked down in their travel and sit at 130mm, instead of 150mm at rest.
Turn bike upside down. Remove 5mm hex bolt on air side of lowers and depress valve to bleed neg air spring. Forks immediately grow in length back to 150mm.
Came good and rode for a few weeks. Serviced fork, 200hr service ride and it’s back to its old games.
Plus and minus air chambers are ment to equalise, but neg side is holding pressure sucking forks 20-30mm into their travel.
Any ideas what may be wrong ?

 

[2unfit2ride]

Have you tried taking all the air out & compressing the fork then sliding a small cable/zip tie down both seals/wipers & then pulling the forks up to full extension, release any air in the fork & then remove the cable ties (all whilst keeping the forks at full extension)?
Worked for me on a solo pike although I still think there may be an internal leak leading to increased neg air over time as I never seem to get full travel from then at recommended pressure.
Worth a go for the 5 minutes it will take you.
Cheers.

 

[steve_sordy]

I had a similar problem on my Pike solo air. A lubed zip tie down the side of the seal did the job!

 

[outerlimits]

Have you tried taking all the air out & compressing the fork then sliding a small cable/zip tie down both seals/wipers & then pulling the forks up to full extension, release any air in the fork & then remove the cable ties (all whilst keeping the forks at full extension)?
Worked for me on a solo pike although I still think there may be an internal leak leading to increased neg air over time as I never seem to get full travel from then at recommended pressure.
Worth a go for the 5 minutes it will take you.
Cheers.

The problem is not air leaking into the lowers. When I bleed the neg side of the air spring it all comes good. The neg and pos spring chambers aren’t equalising.

 

[2unfit2ride]

Is there a neg air bleed procedure then? I have read that the real cure is to have a new air spring installed, often under warranty as its a known problem.
Cheers

 

[outerlimits]

Is there a neg air bleed procedure then? I have read that the real cure is to have a new air spring installed, often under warranty as its a known problem.
Cheers

Yeah,
Have to take out the bottom 5mm Allen bolt from the lowers. There is a valve in the end of the air shaft to depress to bleed the air out of the neg side. Then you have to re inflate the fork like normal, and reset the sag.
The pos and neg side should equalise, but the air is getting trapped in the neg side.
I don’t know why this is happening ( even after servicing)

 

[Tim29]

Your air piston seal has gone bad. Take fork apart replace the piston seal and you be good as new

 

[Russell]

I had the same problem, a new pair of ohlins coil forks fixed it nicely.

 

[Tim29]

T

I had the same problem, a new pair of ohlins coil forks fixed it nicely.

That’s a very expensive way to fix a 12 dollar seal. Increase your service intervals and use a better quality oil and that want happen nearly as often

 

[Al Boneta]

T

That’s a very expensive way to fix a 12 dollar seal. Increase your service intervals and use a better quality oil and that want happen nearly as often

Forking A!

 

[outerlimits]

Your air piston seal has gone bad. Take fork apart replace the piston seal and you be good as new

I have just had it completely apart and replaced all the seals for the 200hr service.
And first ride, I had the problem again.
I used all RS branded products as recommended by RS. The air side only has grease in it. I lubed it as recommended by the service manual. Cleaned everything up with isopropyl alcohol too.
I’d replace the 32mm pogo stick Reba but like the fact I can ride faster than everyone I know running Fox 34’s - 36’s, Ohlins, Pikes, Yari’s ect. Really pisses them off I can charge harder downhill through rock gardens quicker. They can’t believe i’m On 32’s lol

 

[Slowroller]

The first Rock Shox DH forks had 28mm stanchions and a whopping 80mm of travel...

I don't know exactly what's inside the Reba, but if you use too much slick honey inside a pike, you can seal off the notch that allows the chambers to equalize.

 

[hemi.rokingi]

Like @Slowroller said, there’s a port between the pos and neg chambers that is supposed to allow them to equalise. If there’s even a tiny bit too much grease the port can become blocked and will cause the symptoms you are describing. Probably worth pulling the fork apart and cleaning, however I know people sometimes pump their fork up to near max PSI, and then bounce around on it (“bounce” makes it sound gentler than it is) to try and dislodge the grease.

 

[outerlimits]

Like @Slowroller said, there’s a port between the pos and neg chambers that is supposed to allow them to equalise. If there’s even a tiny bit too much grease the port can become blocked and will cause the symptoms you are describing. Probably worth pulling the fork apart and cleaning, however I know people sometimes pump their fork up to near max PSI, and then bounce around on it (“bounce” makes it sound gentler than it is) to try and dislodge the grease.

So yesterday I lost all pressure in the fork in a split second.
Returning home I pulled the air shaft out, cleaned and inspected everything 3 times just so I did not miss anything. All looked fine so reassembled. The equalising port will clog with grease no matter what when installing the air shaft. Forks run at and around 100psi, which is enough to clear the port of any grease.
What I think is happening is the air is blowing past the piston seal into the negative chamber. This does then not allow the fork to move to the position of the equalising port unless you use brute force to extend the fork to that point.
I had serviced the fork like 3 rides ago, so the print on the piston head should be fine. So either I have installed the wrong oring or have a faulty oring. No damage is visable to the air shaft under a magnifying glass.
I have ordered another brand of seal kit to install through the week, and hope this resolves it. Otherwise I’ll have to source a new air shaft, or new forks. It’s still sucking into its travel, so something is not right.

 

[hemi.rokingi]

So yesterday I lost all pressure in the fork in a split second.
Returning home I pulled the air shaft out, cleaned and inspected everything 3 times just so I did not miss anything. All looked fine so reassembled. The equalising port will clog with grease no matter what when installing the air shaft. Forks run at and around 100psi, which is enough to clear the port of any grease.
What I think is happening is the air is blowing past the piston seal into the negative chamber. This does then not allow the fork to move to the position of the equalising port unless you use brute force to extend the fork to that point.
I had serviced the fork like 3 rides ago, so the print on the piston head should be fine. So either I have installed the wrong oring or have a faulty oring. No damage is visable to the air shaft under a magnifying glass.
I have ordered another brand of seal kit to install through the week, and hope this resolves it. Otherwise I’ll have to source a new air shaft, or new forks. It’s still sucking into its travel, so something is not right.

Hm! Sounds really weird. I’ve got fingers crossed for you and look forward to how you go with the new seal kit.

 

[outerlimits]

Hm! Sounds really weird. I’ve got fingers crossed for you and look forward to how you go with the new seal kit.

New seals in, and it is still loosing air.
But I have just found out where from.
It’s leaking from the fork stanchion, where it is press fitted into the csu at the factory
I’m going to try get warranty on this 12 month old fork.

 

[hemi.rokingi]

New seals in, and it is still loosing air.
But I have just found out where from.
It’s leaking from the fork stanchion, where it is press fitted into the csu at the factory
I’m going to try get warranty on this 12 month old fork.

Ah right. How did you manage to work that out? Well done.
Can’t see why it wouldn’t be covered by warranty if it’s only 12 months old.

 

[outerlimits]

Ah right. How did you manage to work that out? Well done.
Can’t see why it wouldn’t be covered by warranty if it’s only 12 months old.

Going through all the checks to see where losing air from. Sprayed soapy water around air cap and valve. Some leaked down the leg, and was bubbling away madly.