Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 999 / 749 > White lining (tyres not the other stuff)

[BIG-G]

My 749 white lines a great deal. Tyres are good (mich's) I've ajusted the sag to close to recommended. (35/30mm)
It also sits up greatly on the brakes.
Is this all normal?
Thanks
G

[Harv748]

My bikes have done both in the past...but not any more.

The white lining is almost certainly down to the tyres...mine was due to the rear being to small for the 6 inch rim (180 instead of a 190), causing the profile to be really flat across the tyre...therefore snaking all over the place whenever I crossed over banding/white lines etc. New 190 on the rear sorted that. Obviously if you have a 5.5/5.0 inch rim then a 180 is the choice.

The same effect can happen if the tyre is starting to square off or is under inflated.

As for the sitting up on braking...I think this is more down to the overall suspension/geometery set-up. You need to look at EVERYTHING and start from the basic static settings and work from there. Set Sag for front and rear. Set loaded sag for F/R. Is this possible...do you need stiffer/softer springs? Ride it and set the compression/rebound to suit...it is possible to achieve a set-up that minimises the tendency for the bike to sit up under braking...but its not a 2 minute job. I would suggest that you got it set-up by a pro if you are not to sure how to do it yourself?

[BIG-G]

Originally posted by Harv748
My bikes have done both in the past...but not any more.

The white lining is almost certainly down to the tyres...mine was due to the rear being to small for the 6 inch rim (180 instead of a 190), causing the profile to be really flat across the tyre...therefore snaking all over the place whenever I crossed over banding/white lines etc. New 190 on the rear sorted that. Obviously if you have a 5.5/5.0 inch rim then a 180 is the choice.

The same effect can happen if the tyre is starting to square off or is under inflated.

As for the sitting up on braking...I think this is more down to the overall suspension/geometery set-up. You need to look at EVERYTHING and start from the basic static settings and work from there. Set Sag for front and rear. Set loaded sag for F/R. Is this possible...do you need stiffer/softer springs? Ride it and set the compression/rebound to suit...it is possible to achieve a set-up that minimises the tendency for the bike to sit up under braking...but its not a 2 minute job. I would suggest that you got it set-up by a pro if you are not to sure how to do it yourself?

Thanks Harv,
Tyre right size so will play with pressures and your right about the brakes so will start from scratch
G

[Col996s]

Suffer from a similar thing.

When there is a filled in trench in the road where they've laid a pipe the tyres just want to follow it and it feels most disconcerting.