Front end shake when braking KZ550

I have been experiencing a wobble/shake on my KZ550 when stopping. This really only happens at full stops during the last couple feet, its a feeling like you are going over a bumpy road. It happens less (or I feel it less) when I have a passenger. Overall brake function seems good - tapping going into a turn or even just rolling in and out of the garage results in good firm braking.

The first thing I did was check the brake fluid and lines, tire pressure and fork pressure. This weekend I put in new front wheel bearings. Still happens.

Any suggestions on what to troubleshoot next? Could this have to do with the steering stem bearings at all?

See if it happens when using rear brake only; then try front brake only. How old are your rear shocks? Ed

Thanks for the reply. Only happens when I use the front brake. No rear shocks, I redid the bike as a hardtail.

A "pulsing" sensation while applying the front brake may result from warped disc(s).

If the problem has persisted for a while, would inspect the front tire to see if there's any "cupping."

Good Fortune!

In addition to what Patton said bout the tire...

The manual describes how to check the steering bearings.

It could also be the fork bushings are worn out. But usually if they are bad, the forks will leak oil.

It looks like you have no front fender. I would temporarily put one on and see if that helps. The LTD forks are longer and prone to deflect. Since you only have one brake, the fork with the single brake deflects more. Normally, a fender, with it's internal bracket, reduces the deflection by transferring some of the load to the other fork leg. At higher speed, the brake has an overall steady amount of grab and the fork deflects a constant amount. But as you slow down, the brake starts to grab unevenly so the fork deflects and returns as the brake grab pulses. This will feel like a wobble.

It is most likely a combination of all of the above issues. Any 30 year old fork with a lot of miles will be "loose" internally, so it can't be eliminated totally, but it should be able to be reduced to where you don't feel it.

If the fender helps, and you don't want it, you can try a fork brace, or just use the brace from the fender without the fender. I think you can grind the rivets off.

You have no front fender, & I don't see a fork brace, that, can cause instability of your forks. & cause wobbling
Pete

I type slow loudhvx !! :laugh: :laugh:

:laugh:

Thanks for the replies gang, Im going to dig into this stuff in the coming days. Your info about deflection makes a ton of sense to me and I was pondering something along those lines when I had the wheel off this weekend. I think you guys are on to something and I appreciate in the input.

BTW, great old-school chopper look.

If you are in Chicago, try to make it out to Five-star bar on the first mondays of the month for bike night.

ChicagoLTD wrote: ...This really only happens at full stops during the last couple feet, its a feeling like you are going over a bumpy road.

I'll bet it's pretty noisy to boot. As the others have said, it's time to service the head bearings.

I'm thinking that the bumps in the road are caused when one of the stem bearings bangs over against it's bearing cup because there's just too much clearance.

If you like the way your bike rides now, you'll be blown away the difference a properly adjusted steering stem makes.
Good Luck
Bill

Thank you again everyone, for all the input. After messing about with this for the past several weeks I still haven't been able to isolate the problem despite going through all the above troubleshooting. I put everything back together save for the caliper and took a look at my rotor, it seems warped and I'm annoyed with myself for ignoring this possibility earlier.

Heres a link to a short video I made of the rotor spinning, Id like some additional opinions so I can get hunting for one of these asap.