Slight wobble from front end

[Arfa]

I've noticed a tiny bit of wobble from front end through the bars, every now and again over this last few weeks. Certainly don't notice it all the time and it's not a visible wobble. Usually notice it if I take one hand off the bars (to wipe visor etc), I can feel a slight wobble in hand on bars, even when I grip them very lightly. I've also noticed from the front wheel being a spot twitchy when pulling a sharp turn at low speed e.g. pulling into a tight junction, though I can't be certain if that's new.


Have checked tyre pressures and noticed it when carrying same weight in top box as I usually do, and both with full/empty tank. Front tyre went on over a year ago.


Any thoughts? Wheel bearings or something like that? Tyre out of balance? Bike has been down a couple of times, but that was July and September, fairly sure this has appeared since. Anything straight forward I can check?

[dcurzon]

i had terrible wobe from mine, remove hand from bars and it would try and tank slap like crazy!  In my case, it was the front tyre, carcass had shot on it, deforming the tyre.
 
In your case though, i'd do a few things...
1. check the bar ends are in place, remove and refit the oter way around (right onto left, left onto right)
2. since you mention top box, maybe stiffen up the pre-load on the rear a notch or 2.

[Ruby Racing]

Handling issues are more often than not down to tyres, so check them thoroughly first and the pressures.


However if it happens at low speeds as you said, then maybe it is the bearings. What sort of mileage has the bike done? To check the bearings hold the forks and try and move the wheel from side to side. If it does a little then bearings a re shot. New hearings are only about £10 to buy and fitting is not too difficult.


Also check your headstock nut is correctly torqued up. Not so much the one on top, but the ones under the top yoke. Refer to the manual for the correct tightening sequence as from memory you tighten the bottom one to a certain amount, slacken it off then re-torque at a lower setting. Then do up the lock nut above it.


If any of your crashes involve hitting something with the front wheel you may have damaged the bearings or bent the wheel spindle. The bike I'm currently modifying and a front end crash (enough to snap a fork) and the wheel spindle was bent and the bearings damaged.

[stevierst]

I've had 3 boxeye's, and my last one shook it's head like a wet dog when you let go of the bars. It got that bad that it would have totally tankslapped itself to death if i let it.

I tried changing tyre pressures, weight in the topbox, bearings, suspension, all apart from the tyre itself. No change, same speed range where it started. If all else is in order, it's pretty much going to be the tyre!

[AdieR]

What mileage / condition are your tyres in if the front went on a year ago? How long has the back been on?

[Ruby Racing]

I agree.

Reminds me of a European track day I did on a 2002 R1. I always used Metzeler Rennsports (Racetecs now), however I had to buy some whilst away as the circuit was wearing the tyres out really fast on one side. I had to buy some Michelins. Even in a straight line they felt unstable compared to the Rennsports. Then exiting one corner I had the mother of all tank slappers, so fierce it pushed the pistons back into the brake callipers! Luckily I knew why I had no brakes at the next corner and managed to pump them back into operation again and made the corner. After that I put the old Rennsports back on and had no more issues. I also ordered a steering damper.

[darrsi]

Bit more involved to check but uneven or incorrect fork oil levels can also cause the wobbles.
 
If you ever consider checking it, i found replacing it with 15w oil rather than 10w oil made a huge improvement on handling.

[Paul]

If it were me I'd have the wheel balance checked first.
Shouldn't cost a lot.

[His Dudeness]

Check if the wheel rim is damaged where the tyre meets the rim

[Arfa]

Front tyre is Metzeler Z6, done about 7000 ish. Back is also a Z6, went on last Summer, probably done half as much.

Both offs involved no collisions, just slid down on floor.

Will check pre-load, however weight being carried hasn't changed since before I noticed the wobble. Guess rear spring may have aged...
I'll double check tyre condition etc.

I might just drop by a garage to double check balance, head stock and suss our bearings etc. All of which shouldn't break bank.

[Deefer666]

Is it only when you have the top box fitted as its a known "glitch" with the FZS that the air flow over a topbox gives a slight wobble on the front at speed.... This increases as the tyre wear increases.

[Arfa]

Dunno TBH, I rarely ride without the top box. It is a large 52 Ltr Maxia one...

[Punkstig]

See if balance weights have fallen off, if not, unfortunately, as you can see from above there are many many things that can be the cause of this and it may take a while to figure out what it is, for me it was a bent fork!

[Ruby Racing]

7,000 miles on the front tyre sounds quite a lot to me. Could have squared off.


Check the easy stuff first, or put another way, the stuff that costs you nothing!

[Arfa]

Quick update to this issue:  Turned out to be a combination of a slow puncture due to valve on front tyre slowly working it's way loose and the front wheel getting on a bit a squaring off some. Only actually noticed the leaking valve when it wouldn't hold air for more than a day... doh! Got new tyre too, and all wobble gone. Handles a feck load better now too. Mad how you get accustomed to an old tyre over time, only with a new one on do you realise how bad it really was.

[Ruby Racing]

An awful lot of handling issues are down to tyres, either condition or pressures.


Glad you got it sorted out. 

[ChristoT]

I always found the topbox rather unbalanced the bike, and that it would slap about a bit with one on.

Solution: fit a towbar!!