Cafe Racer Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
405 Posts
Discussion Starter #1
On the directions to progessive spring installation's that I have read posted on various forums, its stated to install the tight coils down..this mainly to help center the spring better in the tube.

While I know that a progressive springs rate is not affected by orientation , its own center of balance can affect your unsprun weight a slight bit and that tight coils placed down could lower the bikes overall center of gravity..

Ideally wouldn't the best gain be by placing the 'bunched end' up,
though this is leaving the center of gravity higher?

I have seen coils placed on shocks in both positions and thought this same thing...

Are they placed wrong?? (to me , the bunch down just looks wrong ...)
 

·
Registered
Joined
·
7,014 Posts
I doubt there is any measurable difference. There is more sprung weight difference on your bike depending on if you took a dump today or not. The glass of water you just drank would yield more results than the spring turned upside down.
 

·
Registered
Joined
·
2,670 Posts
We always treat shocks/springs as half unsprung. I think it actually depends a little on the leverage ratio but that requires math I don't know how to do.

Your idea that moving the heavy end changes CG is sound. If you weighed the ends of the spring like with one of those scales the weigh connecting rods with when balancing or calculated by total weight then figured out the volume of the spring. You know like pie are squared. You're moving the difference between the light end and the heavy end half the length of the spring.
 

·
Registered
Joined
·
6,587 Posts
The tighter coils are normally placed towards the top of the fork to reduce unsprung weight. The bottom part of the spring moves with the wheel and hence you want to have the "lighter" part of the spring down there.

In the real world / seat of your pants it probably doesn't make a lot of difference - as long as you have both springs in the same orienation it will be OK.
 
1 - 4 of 4 Posts
Top