[maddog17]

i thought i remember a friend of mine telling me a way of setting up a rear shock with using a percentage of your body weight. i've got a Manitu for my rear and on their site they say to measure before you on the bike then after you sit on it and use the little rubber o ring to measure how much compresion happened. am i right in remembering the % of weight thing?

 

[oldskoolbiker]

Using % of body weight is totally not correct. Think about it. Different brands of shocks will have different air volumes, also there is the leverage ratio to consider. Two bikes could have the same travel, but one frame could use a shorter shock and therefore would require more air pressure to have the same feel.

Now the method to use is calculate the %of sag. Typically for trail riding you want around 20-25% and for Freeride/DH you want like 30-35%. Sag is the amount the shock compresses when you sit on the bike.

So you need to know the stroke of your shock. For examples sake lets say the stroke is 2 inches. Now when you sit on the bike for 25% sag the shock should compress 1/2 inch. You would use the o-ring on the shaft to mark the distance. Push the o-ring all the way up, and then sit on the bike. Get off and measure the distance the o-ring moved. Adjust the pressure accordingly.

 

[maddog17]

ok, what you said makes perfect sense. i was just looking for an easier way to figure out how much pressure to run. Manitu doesn't list a max pressure for the shock so i guess i should email them and ask what it is. but in the meantime i'll just do what they list on the manual and see how it works out.