Fork problem

Forks have developed a knocking sound when you apply the brake. I removed them from the bike & the right hand side one has a loudish knock when you compress it. The spring is the right length for the year of the bike. The 10w fork oil has the correct air gap. I assume the problem is inside the fork. Any advice would be welcome.

Sounds like a loose steering stem nut, check that its tight enough.


Could also be worn out bushings inside the forks, with the wheel off but forks still in the clamps check there is no forward/backward freeplay between the stanchion and slider. If there is then your bushings need replacing.


Is your fork oil fresh? If its old and has lost its mojo then they forks may be rebounding as they decompress.

Hi. The forks have been removed. the oil is fresh. I will put the stanchion in the vice & check for bush wear as suggested. Thanks

bushes are the classic thing people quote when these problems come up, personally though i have never seen a bush that has become over worn on a modern bike. Only those damaged when forks have been taken apart with a bit too much enthusiasm.


Fortunately they are cheap, but you need to pretty much strip and rebuild the whole fork to get at the little buggers.

Put the fork leg in the vice & checked for play in the bushes. They are ok

How did the steering stem nut check out?

\The forks are off the bike. When you compress the right leg you get the clunking sound. the left one is ok. I cant figure out how checking the stem nut will alter this.

https://www.youtube.com/watch?v=vrmYJgcGX30

This is a good video on taking forks apart, maybe it will help.

This guy on the bikers oracle forum had essentially the same problem, sadly he didn't find a solution:

http://www.bikersoracle.com/cb500/forum/showthread.php?t=2609&highlight=clunk

Don't know if you have a CB500 or CBF500, but it would be worth disassembling the fork to check if anything seems wrong (it isn't particularly difficult).

Good luck...

I'd strip the leg down and make sure it's assembled correctly; I once did a rush job on the fork seals and completely forgot to fit the bottom cup that the damper sits in; item 8 on this diagram.
Needless to say I cursed myself and had to strip & rebuild the leg!

After watching the excellent fork strip video clip left by HomeBrew, I've decided to overhaul the forks. Trouble is anything can happen when I pick up the spanners ,hence the Sodslaw monica.
Thanks to everyone who posted advice. I'm going to Fork off now.

Remember, the forks will be with you, always!

Go fork yourself

I've rebuilt mine without any problems - just be methodical and patient and you won't have any problems.

If you do have a problem you can always ask on here - there is a fair chance that someone else will have had it before and know the solution (or sometimes more important - know there isn't a solution).

Im sure a knife day working on the problem will have you back on the road spoon.


Seriously though, just got for it. The biggest thing to watch for with fork rebuilds is to not drop/scratch the chrome. If you have any issues post on here.


I also have a bunch of various fork internals you are welcome to if you find anything missing or broken.

Any update on this? Did you find the source of the sound?