Importance of correct fork oil wt

[oldstinky75]

Was thinking of servicing my Rockshox solo air R recently when I noticed in the service manual that I needed 2 different fork oil weights, 5 for the upper and 15 for the lowers. Is the type of oil weight crucial, in that the wrong one will affect performance or reduce longevity?

 

[The Duckmeister]

Heavier oil is used for lubricating the seals, because it stays where it's needed better. Lighter oil is used for the rebound & lockout systems, so it needs to be able to flow through the mechanism. Using oil that's too heavy will retard fork performance 'cos it won't flow quickly enough.

 

[bell.cameron]

Its not going to kill your forks if you put the wrong stuff in. There was an article a while back about servicing your boxxers with water, and the only thing it did (in the short term) was mess with your compression and rebound speeds.

 

[moorey]

Its not going to kill your forks if you put the wrong stuff in. There was an article a while back about servicing your boxxers with water, and the only thing it did (in the short term) was mess with your compression and rebound speeds.

Article?
or thread by theo the fuckwit for a once off emergency that killed his forks...?

 

[Shredden]

Article?
or thread by theo the fuckwit for a once off emergency that killed his forks...?

A C+ in year 11 English would easily qualify me as a journalist I would say.

Still have those forks under the work bench. Should put them on the 951 for a giggle.

 

[moorey]

You should totally do that.

 

[SummitFever]

Use good quality suspension oil in the damper. Note: oil ratings like 5wt, 10wt etc. can be quite inaccurate. One oil company's 5wt may be similar to another company's 10wt. Read this article for a good explaination and a useful table listing most commonly available suspension fluids. The table will allow you to see how close an available fluid may be to what the manf. recommends for your fork.

For non-damper oil, like that used to lubricate the lowers, the general consensus is that a good quality synthetic motor oil (like Mobil 1) will actually be better than using heavy wt suspension fluid. This "splash oil" only needs to make things slippery. Suspension fluid doesn't offer the ultimate in slipperiness because its engineered to provide consistent damping with only sufficient lubricating properties to stop your damper destroying itself.

For RS forks, use a teflon/silicon based suspension grease to lube the air spring seal head. Do not use oil, it will migrate quickly below the air piston. For Manitou forks with a quad seal (not o-ring like RS forks) on the air piston, use oil.

 

[driftking]

Weight of oil is less important its mostly the viscosity that you need to look at.
It will effect your dampening of you rebound and compression, equally different oil weights are better at lubricating than others. So its prett important to choose a good oil, oil weights can be changed for tuning purposes.

 

[T-Rex]

Use good quality suspension oil in the damper. Note: oil ratings like 5wt, 10wt etc. can be quite inaccurate. One oil company's 5wt may be similar to another company's 10wt. Read this article for a good explaination and a useful table listing most commonly available suspension fluids. The table will allow you to see how close an available fluid may be to what the manf. recommends for your fork.

For non-damper oil, like that used to lubricate the lowers, the general consensus is that a good quality synthetic motor oil (like Mobil 1) will actually be better than using heavy wt suspension fluid. This "splash oil" only needs to make things slippery. Suspension fluid doesn't offer the ultimate in slipperiness because its engineered to provide consistent damping with only sufficient lubricating properties to stop your damper destroying itself.

For RS forks, use a teflon/silicon based suspension grease to lube the air spring seal head. Do not use oil, it will migrate quickly below the air piston. For Manitou forks with a quad seal (not o-ring like RS forks) on the air piston, use oil.

This.

We use the exact manufacturers recommended oil for damping, and a 0-30wt synthetic moto engine oil called "Ultra" for lowers lube on all forks.

 

[oldstinky75]

Thanks for the tips guys. Good thing I didn't break out the olive oil, even though it was extra virgin.:friendly_wink: