So I took both hands off the handlebars today going about 40 mph and I got a bit of a wobble in the front end. It's not noticeable at all when my hands are on the bars, so it's not that big of a deal (yet) but what could be causing this? Front wheel out of balance? If that's it, anyone have a decent place I can trust to balance the wheel and not charge me 6 million dollars?
How do the tires look?Are they cupped?Is the air pressure in the tires set at 33 front 36 rear?Are the steering bearings tight and smooth?Is the rear wheel in correct alignment?Don't rely on the swing arm marks.They are off on most bikes.
Never had that problem on my GSs but did have wobble exactly as you describe on my 85 CB650SC. Front tire was badly worn and cupped and a new tire fixed it briefly but it was not cured completely until I replaced the notchy steering head bearings. Low tire pressure made it worse, keep it up to spec or a bit more. All points Ben just made.
i have the same wobble on my gs, it didn't do it when i first got it though.
tire pressure's right on, but since i got it i've worn the rear tire pretty badly(front's perfect condition) and my chain needs adjusting. after i fix those i will be moving onto checkin steering bearings.
keep us updated if you pinpoint the problem!
This is a common symptom on many motorcycle, particularly larger ones; but smaller ones too. Usually NOT tire balance becasue you would notice the vibes from that in your mirrors first. Uneven tire wear, tires getting way thinner in the middle than they are out in the chicken strips, tires not mounted true, damaged rims, defective tires, swing arm bearings going south, chain with links in a bind -- just lots of things. The rear tire seems to more often be the Huckelberry than not. Loose steering bearing pre-load allows it to happen more easily, but cranking down on the bearings more than normal to create a dampening effct is probably not too cool. Detective work is at foot.
prs
Quote from: ben2go on July 28, 2011, 08:02:55 AM
How do the tires look?Are they cupped?Is the air pressure in the tires set at 33 front 36 rear?Are the steering bearings tight and smooth?Is the rear wheel in correct alignment?Don't rely on the swing arm marks.They are off on most bikes.
Apologies for going a bit off topic but does anyone know what causes front tires to get cupped? Mine have been that way since I bought the bike used and it's not causing any problems but I am wondering how the front wears like that.
Quote from: jmelchio on July 28, 2011, 12:00:10 PM
Quote from: ben2go on July 28, 2011, 08:02:55 AM
How do the tires look?Are they cupped?Is the air pressure in the tires set at 33 front 36 rear?Are the steering bearings tight and smooth?Is the rear wheel in correct alignment?Don't rely on the swing arm marks.They are off on most bikes.
Apologies for going a bit off topic but does anyone know what causes front tires to get cupped? Mine have been that way since I bought the bike used and it's not causing any problems but I am wondering how the front wears like that.
Under inflation is the number one culprit.The other ones are soft fork springs and/or low or no fork oil.
Quote from: ben2go on July 28, 2011, 05:41:55 PM
Under inflation is the number one culprit.The other ones are soft fork springs and/or low or no fork oil.
That would explain it. I just replaced my fork springs and put new oil in them because I found them too soft.
Thx, Joris.
I'm guessing mine is low fork oil because I've got a blown seal that needs replacing (hopefully this weekend.)
Strangely enough, I rode on the freeway and took my hands off the bars and no wobble at all. 65-75 and there was nothing.
Sometimes mine does that, I think the topbox is a large part of the problem. Only needs one finger touching the grip to stop it happening.
Quote from: the mole on July 29, 2011, 01:35:26 AM
Sometimes mine does that, I think the topbox is a large part of the problem. Only needs one finger touching the grip to stop it happening.
To much weight behind the rear axle center line will unload the front end enough to cause wobble and possibly a full on tank slapper.
Quote from: the mole on July 29, 2011, 01:35:26 AM
Sometimes mine does that.... Only needs one finger touching the grip to stop it happening.
Ditto on my 919. I took of the small screen which attaches to the headlight, figuring it was creating wind harmonics and a wobble with one or no hands. It helped a lot but still had a wobble. Forks, etc, were straight. Suspected the old tire. replaced it with a new one and the wobble is all gone. badly worn tire was the culprit.
Michael