I've been wondering about oil weight conversions. You say that 5wt really doesn't exist, yet when I buy Spectro fork oil, it is sold at 2.5,5,10,15,20 wt's
No SUS conversions are given. Could you elaborate on this for me?
I have found that most oil labels list a SAE spec for suspension oils. The fact is that is a Crankcase related test. Saybolt (SP) Universial Seconds or SUS is a measurement test that is more approerately set-up for hydraluic fluids. There are others.. I think SAE spec is used to make it easy for the public, however there are huge differences between one "5wt" and another but SUS numbers seem very consistent brand to brand.. (As they should)
When I looked at a Sybolt comparison chart, I noticed that there was a dramatic change in the rating of the oil when test ran at higher temp. I realise that oil will become less viscous at higer temperatures and I'm wondering just how much effect temperature has on the suspension set-up. I'm sure the lower weight oils don't change drastically as the higher ones do, but it must have at least a little effect on damping from a 70 deg cloudy day to 95 in the sun. Any thoughts on this Jeremy?
It's been a while for this thread to return but actually the only real diffrence is from ambient tempeture to operating temp. So don't bother changing your shock oil for ligther fluids. Unless you could redesign the whole system you would find it worked really bad. So yes there is a change but once your rolling it does not seem to make much differenced other than most tunning circuts work much better.