749r instability.
 

Hi guys having gone to assen wsb at the weekend a proplem that has bothered me from day one of picking the bike up reared its ugly head again, not all the time but when there seems to be a bit of a wind in the air the bike becomes very unstable from about 80mph onwards. The bike goes into a wobble/weave on the front end and sometimes at higher speeds is so bad that to throttle off seems the best option, i know today in msn the 2005 models are loosing some vents but i need to know if anyone else is getting this proplem and if thay have managed to do anything to rectify it. I had a 748 before this and never once experianced anything like this.

Wheres your steering damper set to?

I doubt it's the steering damper if it's a low frequency weave. Try raising the rear ride height/pre-load, or drop the front. More often then not, it's caused by not enough weight over the front. How heavy are you?;)

What tyres is yours on?Mine is on diablos and although my damper is wound right off mine only has tiny bit of wobble,mainly in turbulant air following lorrys.
Did the dealer you bought it from set the bike up to suit your weight and riding style?

Thanks for replying guys, right the steering damper is set on 4clicks clockwise and i weigh nearly 15 stone plus my leathers, i have not touched any settings on the suspension at all.

boyo,
i live in germany ,land of the autobahn, my 999s hits the rev limiter in top and shows 282 kph , ive never had a problem with instability or weaving ,just buffeting from the wind as its hard to get out of the airstream at high kph

Boyo, check the rear suspension setup. This can almost certainly be tuned out by suspension adjustments.

My out of the box 749s needed the rear sag to be reduced by over 10mm, dont sound much but it nakes a difference.

the bike came with michelin pilot race and iv just put avon azaros on to go to holland, the proplem is the same with both tyres.

My 999S rear suspension was not at the factory standard settings when I bought it. Compression damping was about right, but rebound was wound up big time! It didn't unduly affect my handling, but it's worth making sure they are at the factory standard, to start with.
Also, make sure the tyres are correct make/size/pressures for the 749R.
Agree with Felix, probably not a steering damper issue at all.
749/999s seem susceptible to crosswinds (in my opinion) but this should manifest itself as a desire to change direction, not a weave or wobble.
My two cents (nearer three, probably) :)

take it back and ask for all the suspension tollerances to be cheaked

ie head bearings ,swing arm piviot bearings and of corse wheel bearings .
just because its new dsn´t mean its ok.

I have the same problem with my 749R and to be honest i really thought that something was loose on the front end and it made me feel very wary the first once or twice that it happened.
The bike seems to get this vague wandering feeling in the front as though there is a strong sidewind and had me really concerned as my 999S did not do this.
I have not touched my suspension settings ,I just presumed that they were correct from the factory.
It is going for its first service soon ( overdue, dealer busy) so will mention it to them.

My 749R is totally stable right up to 150 mph (obviously on closed roads officer :lol: ) , suspension is set as per MCN guide for 999S , I weigh 11 stone + leathers...........................


Don't hold on quite so tight , relax :sing:

11 stone!!!!

someone buy that man some pies!

.. and some beer ...

I had a similar problem on my 999 at brands hatch going down pilgrims drop earlier this year it was particulaly bad when overtaking at speed, Last week under the same circumstances the bike was totally stable. the diffrerence?aftermarket race bodywork with no conformal aerofoils at the side and no upper air ducts in the nose cone.
Try taping up the top air ducts (not the air box inlets) and see if this improves things, most 999 riders who noticed tjhought that the bodywork was far nicer looking than the standard stuff


dave

well , I am only 5' 6" :bouncy:

11 Stone wet more like Yellow............

Who you trying to kid:D