feels like buckled wheel when pulling away / moving off

Hi all,

lately I've noticed an odd sensation when pulling away / moving off slowly... it feels like the wheel is wobbling. I've checked both front and back with calipers and there is no movement, bearings are good, discs not warped.

but when pulling away and only seems to be in first at low speed, the bike judders as if the wheel is buckled. its driving me mad, have had 2 tyres on the back, both new, in the last 2 months (one was 3 weeks old when ruined on the motorway by a nail) and wheels balanced on new one being fitted.

any thoughts? it feels like the rear tyre is flat, that sort of wobbly feeling but tyres are up and both at 42

Wow that sure sounds like a bad bearing, I have never heard of anything else to cause that unless you have the wrong tires on the bike.

yeah I thought bearings, all good. tyres, all good and new and the correct ones. U joint maybe?

Maybe u-joint, or maybe a shuddering clutch?

I've had my worries about clutch noise in the past so possible

I suspect the same- but not a wheel bearing. What you describe sounds like it might be a steering head bearing. How many miles on your bad boy?

Picture this; 99% (actually 98.52812%) of the time, the handlebars are perpendicular to the frame. As you ride, all the imperfections of the road bam-bam-bam (sometimes WHACK-BAM- it depends ;-) ) the bearings in essentially the same spots. Over time this creates mated indentations that have the cone settling into the cup in a "home" position. When you push the handlebars, it "forces" this resting bearing up out of that cupped low spot- the resistance you feel is it climbing out- once out/on top again, it feels fine- but you will feel it drop back into that notched "home" spot.

Pretty easy to test for- simply sit on the bike and see if there is such a sweet spot with the bars dead ahead, then slowly push on each bar and see if the resistance follows what I've described. The fix is straight forward, drop in new (and better bearings are available with plenty of arguments about what kind- I'll leave that to other threads); re-tightening the steering head needs to be done perfectly.

970mike said:

Wow that sure sounds like a bad bearing, I have never heard of anything else to cause that unless you have the wrong tires on the bike.

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Check the smc to make sure its not grabbing and the rear brake pads to make sure they are seated flush and not crooked.
Also check the rear caliper sliding dowels to make sure they have silicone grease on them and are moving freely.
Also check the driven flange bearings..when they start going bad it feels like your on ice or loose stones for the first few feet when taking off.

Also check preload unit for fluid loss and setting.
And of course check u joint...steering head bearings...and swingarm bearings etc.

thanks all