Fork oil capacity help

[tic105]

2004 BCR. I'm replacing my fork seals. Not that they were leaking, just damaged while I was doing other work (long story). Anyhow, I've looked at the repair manual and searched the forum and as far as I can tell, each fork leg is suppose to take 170 ml. However, I drained about 460 ml from each leg.

I'm wondering if the 170 ml pertains to the older version of the forks that had a displacement tube inside the fixed tube. BMW omitted that tube on later models (not sure what year). As a result, is the fluid volume now 470 ml - similar to the volume specified for other similar models.

I've seen this discussed on the forum but have not been able to find a definitive answer. Does anyone know?

Thanks - Tom

[tanneman]

If you have the tube in the fork this can be removed. If not then it is 170ml otherwise without the tube it is 470ml.

[tic105]

Thanks for the info.

[BadToTheBown]

Originally Posted by tanneman

If you have the tube in the fork this can be removed. If not then it is 170ml otherwise without the tube it is 470ml.

+1 - This is not definitive but the only bikes I've seen with the displacement tubes are up to 1999. I had them in mine. My 2001 and 2004 forks do not have them. Good luck.

[roverjosh]

How often should the oil be changed? I have never changed the oil in my shocks since I got the bike in 2003?

[Fast Freddy 944]

First and foremost buy a shop manual, I have 2 Hondas, and a thick shop manual for them. Fork fluid is critical for any 2 wheeled vehicle. You also have to bleed the air pockets from each fork by pumping then up. You also have to set the fork oil height correctly. All listed in your shop manual, Progressive suspension sell a nice fork tube oil height tool, it can be found a you local cycle shop.....

[MATPOC]

I always go by the LEVEL not volume, have seen few cases when someone drained the fork, added prescribed volume and ended up hydrolocking forks because they are overfilled (some crashed)

not sure what's in those telelever forks, always assumed they were just hollow tubes?

[Chris Canning]

First things first!! Remember there are 2 quantities that are posted on the net not even the workshop manual has that,you will only encounter a problem if your changing forks over and then trying to get 470ml into an old set of forks!!! Is a learning curve.

Second these ain't telescopic forks a per the normal forks,the oil is just a
little lube for the tubes it's the shock that does the work,I've changed mine twice in 17 years.

[Fast Freddy 944]

Originally Posted by MATPOC

I always go by the LEVEL not volume, have seen few cases when someone drained the fork, added prescribed volume and ended up hydrolocking forks because they are overfilled (some crashed)

not sure what's in those telelever forks, always assumed they were just hollow tubes?

Modern bimmers are funky, spokes on the outside edge of the rims, single sided swing arms, funky front suspension, Me ill stick with the olde fashion scoots......


Yeup that's a big bike!

[tic105]

Just finished changing. 22K on an 04 BCR. Fluid was clear but a buch of crud at the bottom of the tubes. Put in 470 ml per leg (basically what I took out) and put back together.

Did the fluid really need changing? Probably not, but since I had everything apart, I figured why not.

[MATPOC]

Oil lubricates the teflon bushings, the "crud" at the bottom is teflon that came off those, it usually settles and doesn't harm things much, still I take my time to get it all out in case there are abrasive particles.

Does oil need changing? YES, it breaks down, loosing it's ability lo lubricate

Why is the oil level important? Air Gap, it's the space at the top of the fork, between the fluid and the cap, as you brake forks compress, so does the Air in that cavity, it becomes an air spring, giving you progressive damping (not sure it's the right word in this case) Too little oil and forks are soft, too much... you end up with a rigid fork, on the conventional bike it could cause some serious handling issues, with telelever... who knows, it does not dive on the brakes but it does compress over the bumps, so hydrolocking the fork on the bump would have some unpleasant side effects.

Why do I know so much about forks and shocks? Had a job once at suspension shop, mostly forks, but also did a bunch of shocks

[tic105]

Well this was my first time doing a telelever and there's not much to them (just a tube in a tube). As others said, the oil is there for lube only - no suspension duty. I did clean the crud out of the fixed tube.

You do need to bleed the system under zero load though. I just raised the front end and cracked the bleed valves.

[Chris Canning]

Originally Posted by tic105

You do need to bleed the system under zero load though. I just raised the front end and cracked the bleed valves.

It's only after the 10th time of trying that you realise after a couple of compressions on the front and the air is back in and you back to square one and you don't bother

[tanneman]

Don't try to remove the screw at the bottom of the fork leg. It is not worth it.

[BadToTheBown]

Originally Posted by Chris Canning

First things first!! Remember there are 2 quantities that are posted on the net not even the workshop manual has that,you will only encounter a problem if your changing forks over and then trying to get 470ml into an old set of forks!!! Is a learning curve.

Second these ain't telescopic forks a per the normal forks,the oil is just a
little lube for the tubes it's the shock that does the work,I've changed mine twice in 17 years.

+1, not like regular forks where level is critical to suspension reaction, much less so here. If you over fill, it comes out the seals onto your bike. Ask me how I know...

[BadToTheBown]

Originally Posted by tanneman

Don't try to remove the screw at the bottom of the fork leg. It is not worth it.

+1 Only need to remove this IF you are removing the tubes in the early forks, which you don't want to do.

[roverjosh]

That is outstanding info team, thanks. I planned on changing my fluid as I'm powered coating a bunch of the parts this winter for next riding season. I was just worried I was doing harm by ignoring it for so long. As for a manual I couldn't agree more. I love by my manuals for ALL my vehicles. As soon as I buy something , I buy the manual for it. My BMW manual saved me when I broke a bolt on the front chain cover... it had corroded and snapped in block. I never would have been able to get it all back together without that manual.

Thanks all!

[BadToTheBown]

I you are powder coating the tubes, you may have to take the damn tubes out. Somewhere on this forum or the Internet is a good how to. It's not as easy as you would think but doable. I would remove the tubes because the oven temps to cure the powder coating will probably be a problem for the plastic parts of the tubes. The tubes simply displace fluid and are lighter than oil. Albeit more parts, it lightens the front end (lower inertia, faster front suspension response). Good luck...

[tic105]

I removed both forks from my bike and it wasn't too difficult. Here's the steps I used:

1) Lift & secure front end and remove front wheel, fender, brake hose clamps and calipers (tie calipers back out of the way)
2) Remove plastic cap screw and bleed valve from the top of each slider tube
3) Loosen the top triple clamp and handle bar bolts
4) Pull slider tubes up and out of the fixed tubes (go slow as the fit is tight).
5) Remove the dust cap from the top of the fixed tube (you cannot remove the fixed tubes without doing this first
6) Loosen the bolts securing the fixed tubes to the lower triple clamp
7) Pull fixed tubes down and out (again, the fit is tight so go slow and slowly twist the tube back and forth while pulling down on the fixed tube).
8) Installation is the reverse

If you never worked on a telelever front end (I hadn't), the upper and lower triple clamps flop around once the tubes are removed. I was careful not to put stress on the ball joints while removing the slider and fixed tubes.

Also, depending on the year of your bike, you may have a displacement tube within the fixed tube that you will need to remove prior to powder coating. They are held in place by a bolt at the bottom of the fixed tube.

To Bad's point - I'm not sure you can powder coat the fixed tube and then get them back in the lower triple clamp (the fit is really tight). If you only plan on powder coating the lower axel/caliper carrier, I'd be worried about the fixed tube internals - specifically, there is an internal pipe that sits below the pressed in stop for the fork seal that seems to be coated with teflon. Not sure how those might be affected by the powder coat curing process. Also assume the epoxy used to join the fixed tube to the axel/caliper carrier can withstand the heat of curing, but I'd check to make sure.

Good luck!

[BadToTheBown]

Hello Tic - I think the "teflon" looking part might be your inner tubes that eliminate about 300 ml of fork oil. IF you are looking to coat the lower part where the axle installs, I epoxy painted mine instead of breaking the tubes down. Let it sit and cure for several days and it held up great. You can do this without cooking the tubes.

If you do powder coat them, I would recommend not going too thick and use a flat head screw driver to open up the clamps to help the tubes in. I do it between or next to the bold holes. Just a suggestion...