46mm Ohlins Bleeding

[PEB]

I normally use LTR but thought I might save some cash on shipping and labor so I took my Ohlins to a respected local suspension guy. He told me he thought the forks have far to little rebound damping. He gave them back with the adjuster nearly all the way closed. He also told me he could not get one leg completetly bleed of all the air. He thought that it would eventually burp out. Forgive my ineptness here but I know nothing about suspension and how it works. Could his inability to completeely bleed the forks contribute to the lack of rebound damping? How hard is it to bleed the forks, could I do it myself? Despite the fact that I just paid this guy to try to do it for me I feel compelled not to take my stuff back to him. Any thoughts or tips will be appriciated.

Paul B

 

[GMP]

Paul,

They suck to work on, thats why I would never order them special on a bike. If there is air in the cartridge, the oil level cannot be correct in addition to the damping not being consistant. They can be bled, but it takes a LONG time the conventional way (pumping the cartride), more than a guy doing it for $$ is willing to spend to do it correctly. Les has a tool that makes it fast. I think the issue is that it is very difficult for air to escape between the damper rod and bushing, which is the highest point in the cartridge assembly. It took me over an hour to bleed each fork on my Cannondale.

Also, on some of them, the cartridge is a PIA to get out of the fork leg after the base valve is removed. It fits a lot tighter in the foot than on other forks.

I had an idea but never tried it, no special tools:

Install the cartridge, with base valve hand tight but sealing, compress fork.

Fill the fork with oil, pump the cartridge until there is some damping felt, (some oil in cartridge) about 25% should be OK.

Install the cap with no spring with fork compressed

Turn the fork over, remove the base valve

Extend the fork, the oil that was in the cartridge should have moved through the rebound circuit to cover the piston.

Fill the cartridge completely from the bottom and slowly install the base valve

Turn the fork right side up and compress

Remove the cap, fill to the top with oil to fill the gap between the legs

Check cartridge action, adjust oil level, install spring and cap.

Torque base valve

Now, I could be full of crap, its just an idea, but then again it might work. The idea is to let the air out of the bottom of the cartridge upside down with the base valve out. I think Les's tool involves a similar procedure that fills the cartridge before installatrion. After pumping the cartridge for awhile you may be willing to try anything.

 

[PEB]

Thanks Glen. To further complicate matters one of the nuts on the bottom on the fork leg is stripped out so that leg can't be completely dissasembled. It was that way when I took it to the guy. So it sounds like your method might not work for one of my legs . Anyone have a got tutorial site that would be relevant to the Ohlins stuff? I found this on the web http://www.youtube.com/watch?v=C9ICr-DOmdk would it be applicable to my Ohlins forks? I really am lost when it comes to suspension. I can't wait for a new bike with the Shivers!

Paul B

 

[GMP]

Paul,

The eaisiest and probably best thing for you to do is get them to Les. The Ohlins are not the fork to learn on. Les can get the base valve out and do the job right. Did the guy you just took them to remove the base valves or did he just dump the oil and refill? Another cause of lost rebound is bad midvalve shims or a sticking checkplate if thats what it has. For now, try to bleed the cartridge and reset the oil level yourself, if your comfortable removing the springs. All it will take is time and some oil.

 

[PEB]

Glenn,

The forks worked fine when(they had started to leak, so it was time for new seals) I took them in and for all I know they will work fine once back on the bike, his diagnosis of too little rebound was from him working them by hand in his shop. He replaced the seals and refilled the forks and gave up on bleeding them. I am not sure what he did with the base valves other than he showed me where the nut that surrounds the adjuster on the bottom is completely rounded. He said he was able to replace the seals but not able to take the base valves apart. Once again all of this is greek to me so sorry for the confusion. I am now seeing that in an effort to save a little money I will likely be shelling more than I needed to in the first place. I am not very excited about sending them out again and I am sure my wife would be even less excited. One last question what brand of fork is most similar to the Ohlins? I have found lots of stuff on the web but none of it about Ohlins in particular.

Thanks, Paul

 

[Skidad]

Have you looked into sending them to an authorized Ohlins tuning center? There might be one close to where you live and hopefully they can get them apart to correct everything and get them bled correctly. Just another option to think about.


Skidad in MA

 

[GMP]

The closest thing to an Ohlins is probably a KYB, but its still a bit different. All open chamber forks are basically the same, its just the details that are different.

Skidad,

Les is as good as it gets, no need to look elsewhere. Its just the packing and shipping thats expensive.

 

[PEB]

Glen, Thanks for the help. I am sure my bike would not be what it is without your input. On elast question for the day. Anyone have any idea what wt oil Les puts in the Ohlins?

Paul B

 

[Leon_gasgas]

Hi!

After several oil changes of the Ohlins 46 and bleeding them with the usual pumping method, once, as I remember, I didn't do the bleeding well. For the first 10min of a practice they felt soft without any rebound (they were perfect on continuous roots...). After some bottoming and sometimes pushing the (aftermarket) valves on top to release air, they were again perfect. So, fix the broken parts, install on top those cheap M4 bleed valves and go riding. Soon they will be fine...

Now my 07 has the 48 Ohlins and I wouldn't change them with anything. I just removed 10ml of oil and they are perfect for me. 14 out on comp for enduro, 8 out for MX. They work well everywhere...

 

[Dave]

There is an Ohlins fork manual on this site.
http://www.cannondaler.com/manuals.php

 

[PEB]

Thanks again for the replies boys, I love this site! My plan is to go ride the bike on Tuesday ( I try to ride every year on earth day) and then open the forks up for another bleed session and to set the oil level. After looking at lots of info on the net including the Ohlins manual I feel like a tool for paying someone to change my fork seals. I have tackled far bigger wrenching projects than fork seals, live and learn I guess.

Paul B

 

[Kent A]

Öhlins forks do not need to bled at all if they are assembled correctly! The rebound valve assembly and so called "cylinder tube" has to be installed first. This allows you to fill enough oil to cover the cylinder tube completely. If you then carefully install the rebound valve assembly no air will be trapped in the forks.

To do this you will need the one of the special tools from Öhlins (1797-01 or 1797-06 depending on which forks you have). This is the only "required" tool for servicing Öhlins forks.

Kent

 

[GMP]

Well that explains it, thanks Kent. If I had a bike with the forks longer than I had the Cannondale I'm sure I'd aquire the tools and learn to work on them.

 

[Loosenut]

If your going to replace a base valve, let me know. I have a set in my garage. I opted to put in the optional high and low speen compression base valves available from Ohlins. They work incredibly well.

 

[KTMLew]

As Glen mentioned, if you can remove the base-valves and fill the cartridge through the bottom, it's no big deal...

 

[jaysktms]

GMP, your way work great!! Just did two sets of Ohlins that way.
Thanks.