Front wheel noise vibration

[willsleddon]

Gents. I have a 98 900 in good condition and lowish miles. I had a new tyre fitted on the front and new fork seals and oil by a sort of dealer. All seemed well except for a strange driving noise vibration possibly coming from the front end at all speeds and not increasing or decreasing. When the forks depress on a bump there is a notable momentary vibration in the forks as if some resistance is met but this is not a danger and I have done many miles on it. This morning the brakes were intermittent at the front as if the ABS was working but I don't have ABS. Any ideas please. Thanks, Will Chester

[spike240]

Hi and welcome.
How long have you had the bike? And had you ridden it much before you had the work done?
My thoughts are - was the wheel balanced after the tyre change? Changing the fork seals - did they put the same amount of oil in each fork leg?
Steering head bearings loose, but would have been same before tyre change.
Hope you get it sorted.

[m40man]

Makes me think of front wheel bearings. With the front wheel off the ground see if there is any play when you try to waggle it side to side.

If so, remove the wheel & give the bearings a good look.

[bobh]

Also check that the clamp bolts on the upper and lower yokes (triple clamps) are tight. These can sometimes be overlooked when the legs are re-fitted after overhaul.

The front brake judder could be a warped disc, though that wouldn't normally come on suddenly. But check it anyway - easy enough to do while you're checking the bearings (assuming your bike still has a usable centre stand!)

Another check - while the front wheel is up, check for fore-and-aft play in the steering head. If there is any, it could be that the dome nut on top of the steering head has come loose - if that happens it can allow the steering head bearings to loosen off as it is, in effect, the locknut for that assembly. If the bike has been ridden for any length of time with loose head bearings, it's probable that the bearings will have been dmaged by impact, and will need to be renewed.

Martin rightly mentions wheel bearings, but they can be quite badly worn without showing much, if any, sign of play. So spin the wheel and listen/feel for roughness.

And a couple more things - assuming the front wheel spindle was tightened correctly after re-fitting the wheel, did they also tighten the clamp bolt at the bottom of the fork leg? And did they bounce the forks up and down before tightening it, to makes sure the forks travel freely? And is it possible that the caliper bolts haven't been properly re-tightened?

So, basically, look for anything that might be loose! Even if you don't have a torque wrench, and the values for each fastener, you can make a fairly good guess.

Good luck - Bob

[fartooheavy]

This was very useful advice from bobh. I did all the above and it turned out to be the head bearings which I had replaced about a year ago but needed re-tweaking after bedding in perhaps? The vibration was only evident during braking. Thanks to all for the advice.

[CD]

Check your steering with the head bearings "correctly" tensioned. If it steering felt nicer with the slightly slack bearings (ignoring the clunks) they'll need to be replaced.