Any good 7.5wt will do. Mountainbike fork oil is motorbike fork oil.

 

Fox 7wt is nothing more than Torco RSF Medium, found at almost any motocross shop (for a lot cheaper)

 

cool thanks

That's it? Just a rebranding of a common fork oil?

I'll call around and find some and hopefully rebuild that sucker tomorrow. Torco RSF Medium is available lots of places online.

Fox 7wt is nothing more than Torco RSF Medium, found at almost any motocross shop (for a lot cheaper)

 

Fork oil

Hi there, you might want to call Fox, last I spoke with them, they said ten weight now in their forks. 1-800-369-7469

 

Hi there, you might want to call Fox, last I spoke with them, they said ten weight now in their forks. 1-800-369-7469

Their 10wt Green is still Torco and "replaces" their 7wt for the same dampers, their 10wt Red is used for their FIT dampers and is Silkolene Pro RSF 10wt. The label gives it a cSt of 47 at 40 degrees C which is almost the same as the 10 wt Red and seems way too heavy of an open bath damper. I believe the label is wrong.

10wt Green

Old Fox 7wt

Old style Torco bottle

 

You're right

Hi there, you might want to call Fox, last I spoke with them, they said ten weight now in their forks. 1-800-369-7469

I just called them and they said that they now recommend 10wt oil. Which makes me wonder if the fork was originally shipped w/7wt oil a couple of years ago, does the oil weight make much difference at all?

Another post I found says that Fox 10wt oil is actually Silkolene Pro RSF 10wt.

Derek

 

Another post I found says that Fox 10wt oil is actually Silkolene Pro RSF 10wt.

Derek

The RED 10wt for their FIT dampers is, the GREEN 10wt is still Torco

 

I just called them and they said that they now recommend 10wt oil. Which makes me wonder if the fork was originally shipped w/7wt oil a couple of years ago, does the oil weight make much difference at all?

Another post I found says that Fox 10wt oil is actually Silkolene Pro RSF 10wt.

Derek

Does the oil weight make much difference? I think it makes a very, very noticeable difference in the damper. My '06 Fox Van 36 had 7wt in the damper and I could never get full travel out of that fork unless I used a fork spring that was ridiculously soft and basically unuseable for my weight and riding. Changing the damper oil to Silkolene Pro RSF 5wt finally allowed me to get full travel with a good spring match to my weight and riding style. Similar changes in other fork dampers in forks I"ve owned over the years have produced equally noticeable results. Unless the damper is a poor design, one step in oil viscosity should be quite noticeable.

 

Does the oil weight make much difference? I think it makes a very, very noticeable difference in the damper. My '06 Fox Van 36 had 7wt in the damper and I could never get full travel out of that fork unless I used a fork spring that was ridiculously soft and basically unuseable for my weight and riding. Changing the damper oil to Silkolene Pro RSF 5wt finally allowed me to get full travel with a good spring match to my weight and riding style. Similar changes in other fork dampers in forks I"ve owned over the years have produced equally noticeable results. Unless the damper is a poor design, one step in oil viscosity should be quite noticeable.

Agreed, I used to have a Marzocchi that had terrible small bump compliance unless I ran zero air pressure (it was coil with air preload). I switched from the Marzocchi 7.5wt (cSt 26.1@40*C) to Bel Ray 5wt (cSt 17.1@40*C) and it made noticeable difference as I could run the correct sag, get compliance, and not bottom harshly. And the weird thing is that I'm 225lbs so logic would say I'd need a heavier oil.

 

i just buy 10wt and 5wt quarts at the motorcycle shop, easy to blend 7.5wt or any other with the correct proportion.

 

hmmm... I've been trying to figure out what oil to use. I'm interested about the lower weight oil improving performance, but would that increase the wear on the fork, seeing as the oil would be thinner?

type in "fox oil volumes," on Google, one of the links should have charts that tell you what the recommended weights are for the years and models of forks

 

Torco RSF Medium or Mobil or Torco synthetic ATF. I prefer the ATF now. ATF is slightly heavier.

 

Forget the "weight" stated on the bottle of any oil. It's almost meaningless. Some 10W oils have a lower cSt than 5 or 7 weight oils. Comapare the cSt @ 40 degrees to what you have, and match it up with the brand of oil of your choice.

Some reading on the subject, also see the oil chart at the bottom. (written several years ago I think so some manufactures may be using different brands now)
Peter Verdone Designs - Low Speed Damping

 

As has already been said Fox 7wt suspension fluid is Torco RSF Medium which has viscosity of 31.82 cSt @ 40C so you want a suspension fluid that matches this figure because the the weight stated on the bottle means very little really. The best suspension fluid seems to be Silkolene Pro RSF and Red Line but in my opinion Red Line is better as it is slippier, doesn't gum up and is more consistent over a wider temperature range. Therefore the closest fluid they do to Fox 7wt is Red Line (Medium, Red) which has a viscosity of 30.40 cSt @ 40C so just use this.

All the info regarding this is in the below link

Suspension Fluid - Pvdwiki

I've just serviced and done and oil change on my RS Reba's using Red Line (Light, Yellow), which is the closest to RS Fluid, and the difference is quite surprising really. They're really smooth in comparison to before although it's not a controlled test as I replaced the O-rings and the lubrication oil in the lowers with fully synthetic engine oil...that's another discussion in itself as there are people who won't accept motor oil is better for fork lubrication than a heavy weight suspension fluid...but it it