Ok, just to get it out there so there is no confusion, I sometimes do stupid things. Most recently I let the nitrogen out of my rear shock - don't ask. I have read tons on posts looking for a simple answer to my question but the cloud of confusion still hangs low. So here is the deal - I am in South GA with limited shops, none of which can re-fill shocks with nitrogen. There are several tire shops that offer nitrogen but their machines only go to ~120 psi. My 2003 YZ 250 calls for 142. My question - should I just go with Nitrogen at 120 psi or is it better to just use air and get it to 142 psi until I can find a place that can re-fill with Nitrogen? I mostly ride sand, fire breaks and single track. Not a lot of jumping or air time. Thanks for your help!