Speed wobble

[fast and bulbous]

07 plate 24000 miles and the front end has been feeling very "vague" of late. Scared the crap out of myself yesterday when at speed the front wheel started to wobble violently. I backed off and it came back to me but I had to stop to change my nappy. I was loaded up with a lot of luggage and going over 100mph but thats never happened before. Both shocks feel very soft and the back is tightened right up. I guess its time for new shocks. What can i get for real cash?

thanks

 

[Old Codger]

Have you checked the obvious, given her a good going over ?

For Instance

Close look at the front tyre all round for any abnormalities, Lost any Wheel Weights /Balance
( Ive had Tourances crack up and block tread separate )
Pressures ,Tread depths
Wheel run out Been wheelying or bumping over kerbs or rocks
Check bearings inc Steering Head
Tightness bolts nuts fixings Ball joint etc
Suspension settings

Then do it all again at the rear etc etc
Before spending a fortune on new shocks

 

[WindyChuffer]

That happens with a load of luggage on. Try some pre-load on the suspension.

 

[Yonkyo]

That happens with a load of luggage on. Try some pre-load on the suspension.

+1

Wack up the rear pre-load to raise the rear ride height, which will put a bit more weight on the front wheel.

And it's worthwhile doing the checks that Old Codger suggests also...

 

[jwpzx9r]

If you have a lot of load on the bike the sag in the suspension will be all to pot, bound to make a diference to the stability of the bike. I would always look at the springs when loaded up! Of course if you are not going to use the bike loaded all the time you should really check the sag when its under normal load and then when loaded. You should be able to dial in the right amount of preloadfront and rear if you count the number of turns you wind the shock up. Suspension is a black art (ask any sportbike rider) and the rebound and compression damping will also be very badly effected by changing loads... very complicated

 

[Engineer]

Never had this problem with either of my 1200s - maybe the suspension is shot but make sure that you have set the rear re-bound to max (fully clockwise) as well as max pre-load first.

 

[Wapping]

The GSA, when fully loaded, will do that. It will also get its front wheel in the air, when given the beans. The extra weight on the back compresses the rear suspension, lifting the front wheel to skim the ground or fly above it. The rest is simple physics. It's not unusual.

Start with the basics. Are your tyres in good shape and set at the correct pressures? If so, good. If not, deal with accordingly.

Have you had the bike from new? If no, then I might hazard a guess you have no idea what settings previous owners had dialled in or indeed what state the suspension is in. Start from setting the bike back to its standard settings, see owner's manual for details.

What does the suspension feel like now? Crap? Your suspension either needs a good service or replacing.

Does it feel OK? That's good. Now it's just a matter of setting the suspension and tyre pressures to deal with the extra weight. See owner's manual for details.

Any better?

Yes? Job done.

No? Your suspension either needs a good service or replacing.

My suspension started to deteriorate quite markedly at about the 24,000 mile mark, but I toughed it out. The shimmies and shakes / wheel lifting I lived with, in exchange for some fun. At 32 odd thousand the Ohlins went on, front and back. Great kit.

PS One good tip. If it gets bad..... don't slam the front brake on, particularly if the front wheel is in the air. All sorts of interesting things will happen, when the tyre bites. The shakes are probably not as bad as you think. Try an SP1 for the full effect

 

[Deleted account 211025001]

.................... I guess its time for new shocks. What can i get for real cash?

thanks

There's loads of threads on here about replacement shocks that a good search will bring up, but, the two most popular replacements are Wilbers and Ohlins.

Wilburs are cheaper and not as flash but, speaking as somebody who's had them for 35,000 now I'm very pleased with them indeed. As with Ohlins they are spec'd to your weight/requirements.

Andres

 

[Stig]

I was loaded up with a lot of luggage and going over 100mph

Therin lays your problem!.... Been there done that!....

Somedays the bike behaves... Others days it doesn't...

A risk you take when riding fully laden in excess of the BMW recommended speed when fully laden!!...




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[Deleted account 211025001]

Therin lays your problem!.... Been there done that!....

Somedays the bike behaves... Others days it doesn't...

A risk you take when riding fully laden in excess of the BMW recommended speed when fully laden!!...




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Nah, decent shocks and fully loaded equals no probs at three figure speeds.

Andres

 

[slydog]

100

100mph fully loaded

 

[Giles]

.

My suspension started to deteriorate quite markedly at about the 24,000 mile mark,

Yeah but to be fair, you did used to be a fat fecker ....

 

[Stig]

Nah, decent shocks and fully loaded equals no probs at three figure speeds.

Andres

Maybe... But at a price!... As for me... 85 on standard shocks suits me just fine...


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[Wapping]

Yeah but to be fair, you did used to be a fat fecker ....

.....and pounded the guts out of the thing

 

[WindyChuffer]

Nah, decent shocks and fully loaded equals no probs at three figure speeds.

Andres

STANDARD shocks, properly adjusted (front and rear), fully loaded, plus me at 95Kg. No probs at 3 figure speeds. Even with Knobblies on (fitted myself, and not balanced).

It takes a few tweaks with the spanner to get the front right.

 

[Deleted account 211025001]

Yeah, sorry, didn't phrase that very well........you are of corse right, when on standard shocks I never had any issues either.
The Wilbers do feel a bit better planted at high speeds but there was nought wrong with the standard shocks.

Stig, either your shocks are knackered or they could benefit from being set up properly.

Andres

 

[Stig]

Stig, either your shocks are knackered or they could benefit from being set up properly.

Andres

The latter I would say... However, that was long in the past when I rode with default factory/dealer settings... Only tinkering with the rear pre-set..

But not nowadays..

Infact... I would go so far as to say that anyone "test riding" a potential bike purchase should spent a little time (if possible) ensuring that the shocks are set up for them and their riding style... rather than just jumping on it regardless! ... It makes all the difference to the ride... and any subsequent decisions thereafter!



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[Country Bumpkin]

errr

perhaps try riding a little slower and see if the problem disappears !!!

CB

 

[fast and bulbous]

perhaps try riding a little slower and see if the problem disappears !!!

CB

The thing is that until recently it was never a problem and I could regularly ride at that speed with no wobbles. I've just started to feel it over the last few months so something has changed. The tyres are in great shape (tourance) and the pressures are perfect but thats about the limit of my technical knowhow. The more I think about it the more I am convincing myself to buy a good pair of aftermarket shocks and have them set up properly.Im off to Spain in 6 weeks and I want it to be perfect..

 

[Country Bumpkin]

The thing is that until recently it was never a problem and I could regularly ride at that speed with no wobbles. I've just started to feel it over the last few months so something has changed. The tyres are in great shape (tourance) and the pressures are perfect but thats about the limit of my technical knowhow. The more I think about it the more I am convincing myself to buy a good pair of aftermarket shocks and have them set up properly.Im off to Spain in 6 weeks and I want it to be perfect..

I dont know how far you are willing to travel, but its worth giving this chap a call. He's a top bloke and knows pretty much all there is to know about BMWs.

Cheers.

CB


http://scriminger.co.uk/