6th gen forks, fork oil.

Did a full seal, bushing, and oil change on the bike today.

I'm curious as to the effects of oil level on dampening/suspension characteristics. Unfortunately I only had 1 liter of oil so instead of the 544ml (18.4oz) I only put 500ml in each until tomorrow.

I seem to have read the air gap was 100mm but 90-110mm allowed. What will this do overall? And as I'm curious. Why?

 

The fork's resistance to bottoming is provided by a combination of the spring, plus the compressibility of the air above the oil. The air makes most difference when the fork is near to bottoming, and increases the bottoming resistance. So less oil won't be too noticeable until you brake hard or hit a decent bump, then you are more likely to bottom out. The recommended oil level (springs out, fully bottomed) is indeed 100mm.

 

If you have aftermarket springs (usually slightly gauge spring wire), typical oil levels are lower, more like 130mm. Your wee bit low is nothing much to worry about, just more air cushion. What you don't want is too high an oil level, if it bottoms out so to speak, you push oil past the seals.

 

Well that makes sense. I was worried I'd have issues. I'm still going to add the missing oil.

Thanks

 

you absolutely want the air gap to be correct. You will be able to ride the bike but dont hammer it.

 

Hi Dan. have a look at Dave Moss tuning, he is the suspension Guru. Cheers Brian.