View Full Version : Preload on front forks

12-Mar-2009, 05:30 PM
Stupid question maybe but what is the preload on the front forks and how do you set it up correctly?

DPW09 :D

12-Mar-2009, 05:41 PM

I'll try and do a very basic explanation.
Preload is the amount you squish your fork spring (air or coil) before it does anything else.
It helps get the sag of the forks right and relies on the fact that it takes more energy to squish a spring 30mm than it does 15mm. So with no preload your forks would be quite squishy and bouncy when you sat on it, you also might take up more travel than you need to by merely sitting on the bike. Add some preload and you pre-tension the spring which firms things up and makes the fork ride a bit firmer, there's usually a knob that you turn to increase and decrease so you can tune the forks to your weight and the terrain you're on.

There's some more handy advice here http://www.associatedcontent.com/article/533895/a_general_guide_to_mountain_bike_suspension.html

12-Mar-2009, 10:29 PM
its like your forks are already partly compressed whilst they are fully extended... your "pre-loading" the spring...

12-Mar-2009, 10:37 PM
is that the same as compressing the forks just be fore you go over a drop off ?

12-Mar-2009, 11:17 PM
With coil forks you have two options generally.

#1... change the spring to get you in the ballpark
#2... change the preload to fine adjust

You are aiming to have your sag in the right place so you can soak up hits, but the fork can also extend into dips in the trail to smooth those out too.

For general riding, lots of preload is not as good an option as having the right spring in the fork, but it is a balancing act between spring rate and preload to get the optimum setup.

If the use is for general trail riding the answer is different compared to dirt jumping, for instance.