Topic: 1975 CB550 Front End Clunk Sound

[CB750wannabe]

I'm hearing a "clunk" sound when I hit any bumps.  It sounds like it's coming from near the steering stem but I know it can be difficult to know exactly where it's coming from.  I replaced the steering bearings but that wasn't it.  Any ideas?  Thanks in advance! I don't think the forks have ever been rebuilt. 

[Ozzybud]

Is the fluid level correct and the proper viscosity in the forks?

[BenelliSEI]

You may laugh, but I chased the  same kind of noise on my cb750K8 many years ago. Try a zip tie on the speedo cable to the fender loop and the fender stay. Cured my “thunk”. I had a heavy cable and it was whacking the fender stay loud enough I could hear it! Adjusted the speedo gear up a little higher and that cured it.

[denward17]

Did you install the All Balls tapered bearings?

If so you likely have increased the space above/below the fork ears, allowing them to move up/down easily, thus making a thumping noise.

[CB750wannabe]

Thanks for the replies. The clunk was there before and after I installed the All Balls tapered bearings.  Since I have no idea when/if the fork oil has ever been changed, I will try that next. The bike only has 6,500 original miles. I was just writing to see if anyone had any other ideas first. I reviewed the speedo gear and other cables up front and everything is where it should be. 

[bryanj]

At that mileage and age the oil, if still there, is well past its sell by date