Slight knocking noise when going over bumps

[Guest]

I tried searching the forum, but I don't know exactly what I am looking for....

When the bike hits sudden bumps like a pothole or railroad tracks i can hear and feel a slight knock coming from the front end.

I don't have much mechanical knowledge about motorcycles, but if i was going to diagnose this problem on my bicycle, it would be easy: a loose headset. I'd solve that by adjusting the bearing tension.

To describe the sound and feeling, I first thought it was my keychain rattling, but a bit lower in tone. I also can't reproduce the knock by bouncing the front end while the bike is parked or rocking the bike with the front brake engaged. I haven't noticed it during hard braking either.

Is this a normal? I don't' have much experience and may be over analyzing. If not, any advice? Thanks!

[DanTheMan]

Could be you've got dry and rusty bearings in the headset (common problem, the headset gets overlooked on maintenance quite often). Or, also in the area of fork maintenance, it's probably time to do a complete fork oil change and clean, install new seals while you're at it.
Also, check your caliper mounting bolts, make sure they're tight ( I left one loose once upon a time....).

[jknappsax]

I had the same symptom

I had a local shop known for good work install tapered-roller steering-head bearings in my 1978 GS 750, and when I picked it up, I rode about a half mile, then went back for them to tighten the steering adjuster. Problem solved. But the advice to pull the triples and check everything is the best idea.

[ALB80-850]

Did you find the source of the noise?

I had a front end noise as well. Mine turned out to be a loose front fender. The rivet holes became egg shaped and it rattled like crazy. But it didn't sound metallic, so I never checked the fender. Yesterday while cleaning a 1000 miles of wet road grime off it noticed it. Was ready to remove the front end and replace everything.

Andy