Shakey head

Hey guys

I’ve been running a CB as a commuter for almost a year now and it’s been great. I know it’s no sports bike but I have noticed that on the odd occasion when I do give it a bit of a tickle on the twisties it shakes its head a fair bit when you’re trying to quickly flip flop from one side to the other. At 55-60 it’s fine but anything quicker than that at a decent lean angle and it’s quite un-nerving.

I serviced the forks 2 months ago (cleaned the internals, new seals, and replaced the oil with slightly heavier SAE15W) but that made no difference, the tyres are BT45’s at 36/40 and I can’t see anything obviously wrong with the bike – so could this just be me approaching the natural limit of the bike (in standard trim) or could there be something else afoot?

If this is approaching the limit of the bike in my hands (although I’m sure a club racer could get more out of it) then that’s fine, at least I know where it is now. I purchased it as a commuter so I’m not interested in increasing either the handling or performance – I’ve already got an out and out sports bike for silly days. But if this is an indicator of something fishy going on then I’d like to get to the bottom of it.

Thanks

Steering stem bearings? Swinging arm bearings? Wheel bearings?

Not that I have much reference material to build upon. Basically guessing...

stormbringer wrote:Steering stem bearings? Swinging arm bearings? Wheel bearings?

Not that I have much reference material to build upon. Basically guessing...

Shouldn't be the head bearings as they were replaced this year. As for the rest - I'll look into it.

I had a bit of a moan about it to a fellow biker I met while out for a blast on the other bike. He suggested it could be the forks topping out, but I've no experience of this happening on any other bike I've had so I don't know how it would feel. Could it be this?

maybe stiffen your rear shocks a little.

Seconded, more preload on the back so slightly more weight on the front. Might be worth making one definite cornering movement (go in deep and countersteer) then drive out rather than let the bike bounce its way round on a constant throttle.

atb

muttley1

Thanks for all the suggestions guys. I can’t work out how to multiple quote, so I’ll just do it this way instead…

Beresford - I’m fairly average size (6ft, 11.5 stone) and I think I do tend to keep my weight up the front, but I do also weight the pegs quite heavily on this bike as I feel it makes a marked difference (especially in the damp). I’ll maybe try weighting less and concentrate on getting a bit more over the front end.

Tricky – I’ve only got one more click of adjustment on the back, but I’ll give it a try none the less.

Muttley – The issue isn’t so much with holding it in the corner, it’s the transition between getting it from a heavy left lean to a heavy right (or vice versa) quickly. It’s just that second that’s the prob. It gives me the willies!

You could try dropping the headstock on the forks 10 or 15 mil. It'll throw your weight forward a bit more & can help cornering.

ashcroc wrote:You could try dropping the headstock on the forks 10 or 15 mil. It'll throw your weight forward a bit more & can help cornering.

Wouldn't that just make it twitchier in a straight line instead?

The cornering isn't the issue. Hard left - no problem. Hard right - no problem either. It's linking these two together quickly (as you would when you go through a big chicaine or an 'S') is when it all goes wrong. When you haul it up out out the left it shakes its head all the way over to the right and then settles down again (and vice-versa of course). It's a horrible feeling.

Hows the front tyre wearing? When my last tyre (a BT45) was nearing the end of its life the profile took more of a triangular shape. Had a similar head shaking problem during fast direction changes which has gone away since changing the tyre.

Pukka wrote:Hows the front tyre wearing? When my last tyre (a BT45) was nearing the end of its life the profile took more of a triangular shape. Had a similar head shaking problem during fast direction changes which has gone away since changing the tyre.

Oooh.... I've not looked. I'll have a look and report back later. Thanks.

I'll second the tyre possibility. My old BMW R100RS was very sensitive to tyre wear, and a slight shake of the bars was the first sign; getting steadily worse as the tyre neared the end of it's life.

Aren´t the "shakes" natural...."charisma"?

If this was a Ducati, people would say it´s the bike personality bla bla bla....
Now that it´s a Honda, it should do everything like it´s in the books....

Gonzumzum wrote:Now that it´s a Honda, it should do everything like it´s in the books....

Haha
If you'd bought a Ducati, you'd have spent at least ten times as much of your hard-earned money and would most likely be ten times less prone to admitting flaws/faults/bugs.

You know what they say at Microsoft when something craps out? "It's not a bug - it's a feature!"

So, Ducatis have 'charisma'. Bah...

If whatever the bike does gives you the willies, it's bad and must be addressed.

stormbringer wrote:

Gonzumzum wrote:Now that it´s a Honda, it should do everything like it´s in the books....

Haha
If you'd bought a Ducati, you'd have spent at least ten times as much of your hard-earned money and would most likely be ten times less prone to admitting flaws/faults/bugs.

You know what they say at Microsoft when something craps out? "It's not a bug - it's a feature!"

So, Ducatis have 'charisma'. Bah...

If whatever the bike does gives you the willies, it's bad and must be addressed.

Easy tigers!   As my username suggests, my other bike is a Ducati.  I think it genuinely drips with charisma (and not just using that word to cover up for issues), which is probably why I've still got it after 13 years, and in that time I've actually had fewer issues/niggles/bother with it than I've had from my CB over the last 12 months (and the Ducati has the higher mileage too).  I'll admit that working on them is mostly an access nightmare (other than the clutch which literally takes 5-10 minutes to replace - or the back wheel which takes seconds).   But if you're referring to more modern Ducatis then crack on!  I don't like them much either.

As for the willies, I think I've cracked it with all your help.  Body position!  Boy, you have to throw a lot more of your weight over the front that I'm normally used to, but it had the desired effect of no nasty wobbles.

Thanks again folks.