fork oil height

[mr72]

Is there any way to measure/set the fork oil with the forks extended and springs/etc installed?

Inquiring minds.

[sledge]

Drill a hole in a spare cap and make a dipstick 

[mr72]

Ha! I can take the cap off. I just want to avoid having to take both sides apart at once so I can compress the fork, and having to support the weight of the front end of the bike. And it would be nice to not get more fork oil everywhere by taking out the springs and spacers.

[sledge]

I am sure somone of you ability will find a way, equally sure you will then take 250 lines and an hour of your time to tell us all about it and how you did it.

Ha? 

[Big Rich]

Now Sledge, play nice......

Josh, are you worried your oil level is low / uneven?

[qcbaker]

just put the bike on the center stand, then put a jack under part of the frame that's below the engine and raise up the front end until the rear wheel is sitting on the ground. Then you can take the caps off the forks and check the oil level with a dipstick.

[mr72]

Josh, are you worried your oil level is low / uneven?

Yeah, I think it's probably low.

just put the bike on the center stand, then put a jack under part of the frame that's below the engine and raise up the front end until the rear wheel is sitting on the ground. Then you can take the caps off the forks and check the oil level with a dipstick.

That's not a problem, easy enough. I use a ratchet strap and a hook on the ceiling. What's the oil height spec with the forks extended?

[Bluesmudge]

I think all the specs are for fully compressed forks. Once you have the caps off, what is stopping you from raising the wheel to compress the forks? If you must do this with the forks in the tripple trees, raise the wheel and put some jack stands under the forks while you set the oil level.

[mr72]

I think all the specs are for fully compressed forks. Once you have the caps off, what is stopping you from raising the wheel to compress the forks?

Nothing, that's what I'll do. When I changed the oil I did them one at a time so the other leg would support the bike.

[RichDesmond]

Yeah, virtually all specs are for the fork leg fully compressed, with the spring and spacer removed. Good reasons for that, so take the extra time and get a good measurement.

[mr72]

Yeah, that's what I did. Set both to 5.5" from top of the fork tube with the forks fully compressed and springs/spacers/etc. removed. Turns out I had it too high.

[Endopotential]

Yeah, virtually all specs are for the fork leg fully compressed, with the spring and spacer removed. Good reasons for that, so take the extra time and get a good measurement.

Why is that?  For stock equipment I guess that's fine to use the same reference number, if everything stays the same.

But if we change out springs and spacers (which maybe take up different volumes) , isn't what really matters the oil level once all those parts are in place? Functionally, wouldn't it make more sense to get a measurement with the fork at full extension, the native state from where it's doing all it's work?

[mr72]

Yeah, virtually all specs are for the fork leg fully compressed, with the spring and spacer removed. Good reasons for that, so take the extra time and get a good measurement.

Why is that?  For stock equipment I guess that's fine to use the same reference number, if everything stays the same.

But if we change out springs and spacers (which maybe take up different volumes) , isn't what really matters the oil level once all those parts are in place? Functionally, wouldn't it make more sense to get a measurement with the fork at full extension, the native state from where it's doing all it's work?

I totally agree. The only wrinkle is once you modify things often the spacer you insert can protrude past the threads and you can't easily account for the volume taken by the top cap. But those are not insurmountable issues.

I would think measuring with springs and spacers installed will be a much better indicator of how much air volume is going to be present once the fork is assembled.

[RichDesmond]

It's because the trapped air volume at full compression is what really matters. No way to measure that with spring and spacer installed, so we do it with them removed. The volume difference from one set of springs to another isn't very much.

[Endopotential]

Wow, word from the man himself!  That pretty much answers the question.

I have a set of your springs and really enjoy the better ride.  Thanks Rich!

But I installed an aftermarket set of fork caps that are longer on the bottom compared to stock.  I guess I should have changed the fork oil level to compensate?  I just played around with the spacers instead.  The bike still rides fine, so I'll leave it as is for now.

[RichDesmond]

It's probably not enough of a difference to matter. Just set the level 5mm lower the next time you change it.