Steering head shakes when braking

[Manfred]

The roads around McAlester,OK are less than stellar and I've noticed when I brake coming to a stop, the front end chatters a bit. I can see the top of the tree move front to rear about an eighth of an inch - back and forth. I've tightened the collar on top of the tree and things are a little better but still not good. New steering head bearings were installed 2 or 3 years ago.

What do ya'll think is going on and how does a mostly ignorant rider fix it?

[Kurt in S.A.]

To check for proper tightness of the steering stem bearings, put the bike on the center stand and position the bars straight ahead. Give the bars a nudge to either side. If the bearings are too loose, the bars with easily move to the stop, even pick up speed and bounce off the stop. If the bearings are too tight, when you push the bars either direction, they stay where you push them to. Adjust accordingly.

Kurt in S.A.

[Manfred]

Thanks, Kurt. I've checked that - aside from the cables and wiring interfering, the bars go smoothly with no notching but "easy". As far as I recall, I don't need to loosen anything to adjust the top collar on the bearings.

[Bamboo812]

If it is really that far out of adjustment, you'll need to loosen the bottom clamps on the triple tree in order to drop the fork tubes down the same amount that the bearing adjuster has moved. It sounds like this was done incorrectly when the bearings were installed. If so, the top brace will not put even pressure on the top bearing, everything must be in the same plane. When I assemble forks, I mount the top brace with the bearings adjusted, then slide the fork tubes up to match. It can help to have a screwdriver or similar wedge jammed into the gaps on the triple tree, so the fork tubes slide easily.

[Manfred]

Thanks - that makes sense to me. I will do that and see how she improves.

[Duane Ausherman]

The fork thing about falling to one side is fraught with error. The list of what is wrong with that method is long.

What is the year and model? Start with that. I suspect that Bamboo812's idea is a distinct possibility.

[Manfred]

Duane - the bike is a 1987 R80RT. I have printed out a few pages of Snowbum's advice on this topic and plan to dig into it after church this afternoon.

[Manfred]

Other than some gross stupidity on my part while mounting the front wheel onto the forks, things went well. On the ride to work this morning - no shaking at all! Solid feel while braking hard and hitting the myriad bumps along the way getting here.

Many thanks for your help!