i noticed that the bike boucnes around the road a lot more when it's cold.  i checked the rear alignment and the tire pressure and things seem to be OK.  but from 30-50 MPH the rear end bounces around (or seems like it); then it goes away after a few minutes. 

Are these bikes really sensitive to tire temp?  I'm running brand new (<50 miles on them) Metzler's front and rear.

i would say check your tire wear on your bike but there new .. could it be the road ?

could be the roads.  maybe i'm just not used to the twitchiness of 2 wheels yet.  i don't feel it by the time i get to the highway.  (above 60 MPH it seems to go away and wind becomes a bigger factor.) 

This is a shot in the dark, but it could be that as the tires warm up, they become more flexible, and absorb more of the shock themselves. 

Make sure your swingarm and forks aren't loose too. Is it always on the same roads too? try it on some different roads at the same speed. It could also be that you're shivering at 30-50 and then you start to go numb or get used to it after a while and stop shaking 

could this be the rear shock? mine is stuffed and its like a pogo stick when u lean it down at 140km+ the bakc wheel hops off the ground its fun

Quote from: Egaeus on September 28, 2006, 12:13:45 PM
This is a shot in the dark, but it could be that as the tires warm up, they become more flexible, and absorb more of the shock themselves. 

Yep. Cold tires are harder than warm tires.

Quote from: dgyver on September 29, 2006, 04:56:57 AM

Quote from: Egaeus on September 28, 2006, 12:13:45 PM
This is a shot in the dark, but it could be that as the tires warm up, they become more flexible, and absorb more of the shock themselves. 

Yep. Cold tires are harder than warm tires.

I knew that but I'm just not sure if the difference in springiness is enough to account for what he's experiencing. 

Two possibilities to consider, dep on temp:

- Air pressure will change with Air temp (my measured "cold" tire pressures increase when the temp in my garage goes from 40F to 70F).  Dunno if lower tire pressure would cause your bounce or not

- Depending on how cold that cold temp is, your shock oil (is the rear unit an oil shock??) may behave differently.  I had a Z-28 in '92 that rode like an absolute rock when it was 15F outside.

hmm...maybe it's worth looking at the rear shock.  it's not leaking, but could need servicing none the less.  a good winter project...

tires/suspension....everything takes some warming up
think wizing outside in the winter....shrinkage and don't work very well