Triumph Rat Motorcycle Forums banner
  • Hey everyone! Enter your ride HERE to be a part of October's Bike of the Month Challenge!
1 - 6 of 6 Posts

·
Registered
Joined
·
66 Posts
Discussion Starter · #1 ·
What changes exactly when I move the two collars on the rear monoshock from the bottom most position (stock?) up an inch or so?

I've searched every possible combination of words and phrases that I can think of and cannot find a simple answer to this question. I realize there are two for locking purposes. I just don't understand the theory behind this.
 

·
Premium Member
Joined
·
6,462 Posts
They're to adjust the spring 'preload' or 'sag'. If you search on those terms or 'rider sag' or 'static sag' you'll pull up lots of info on Google etc.

Static sag is the wheel's vertical movement from when the suspension is fully extended to when the bike is stood on the wheels with just it's own weight.

Rider sag is the same but with the weight of rider (& gear) on board too.

It allows the suspension/wheel to move down into a dip in the road surface without topping out & tyre lifting off the surface. Roughly, rider sag is set to about 1/3 of the maximum available vertical wheel movement. i.e. If max suspension travel is 120mm, sag around 40mm would be a reasonable base setting.
 

·
Registered
Joined
·
66 Posts
Discussion Starter · #3 ·
So moving these collars up will help the bike from bottoming out (with a rider) on our uneven brick streets?
 

·
Premium Member
Joined
·
6,462 Posts
I'd have thought 'down' to prevent bottoming out? (The shock is usually mounted with the collars/threaded section at the top - shaft at the bottom.) More intial compression of the spring anyhow.
 

·
Premium Member
Joined
·
5,170 Posts
If you have a stock shock, I don't think you will achieve much. Mine was set on the maximum preload and I still had too much sag (35-45mm). The spring was too short to use the other end of the preload range.. most of the available adjustment could be taken up by hand.
 
1 - 6 of 6 Posts
Top