Originally Posted by Steve Russell
52psi seems like a lot of pressure for the preload.
It depends on the rider's weight, but 52 PSI is TOO MUCH - it needs to be between 0 - 15 PSI.
http://www.marzocchi.com/spa/mtb/pro...LN=UK&Sito=mtb
Marzocchi's chart (and manual) is confusing. The actual air pressure that you put in via your pump needs to be anywhere from 0 PSI to 15 PSI. Where the confusion lay is that the chart above shows you POSTIVE AIR PRESSURE - not the PSI you are supposed to inflate to. Postive air pressure is simply the weight that should be present on the fork by body weight, assuming you want ~20-25% of your total body weight to preload the fork. This corresponds to about 20-25% of your fork's total travel to be used up by preload (ie. just sitting static on your bike) - also known as sag.
So - long story short - add as much PSI between 0 and 15 to achieve about 20 % of your fork's total travel to be consumed by sag (just sitting on your bike).
Of course you can fine tune to your liking - it is not an exact science - but do NOT be mistaken in thinking that the chart above shows how much PSI to inflate to - it does not. Again, it only shows by rider weight, how much of your body weight is being used to preload the fork to roughly 25% sag.
I don't know why Marzocchi even needs to keep showing this misleading chart in their manual.
Again, for the MX Comp - the only thing you need to worry about is adding air between 0 - 15 PSI to give you roughly 20 - 25% sag.
Somebody oughta sticky this.