Suspension fork oil weights--what`s the differences?

JamesB

I`m hoping to do more routine fork maintenance, ie regular oil changes follwoing seizeing up of my RS Reba and not enjoying 20 miles riding a semi rigid fork....

I`ve found out now how to change the oils , and works fine but used 5wt; should apaprently have been 15wt; so waht difference do all the various wt oils make? I cna see that a heavier weight oil will make for slower damping as it`s more viscous but what about teh oil bath lubricating, will a light oil make the fork more supple, but not last as long being less tacky?

Can suspension oils also be used as chain lubes??

ta

ps how does basic serviceability (ie oil changes) vary between mfrs such as RS / Fox / Pace?

supersonic

The damper chamber uses 5wt. Always. For RS.

The lubeing parts and oil baths use 15wt.

For service intervals, see the websites.

JamesB

Anyone else have any thoughts about the oil weights for lubeing and fork plushness?? eg. Should a lighter lube oil be used in colder conditions

supersonic

No, it should be as RS says - 5wt and 15wt. Only the older hyrdracoil and hydrair models can be tunes with different weights.

If you go to thin with lube oil it may not stick were needed.

JamesB

Given that fork technology of a stanchion sliding throiugh a set of bushings and being lubricated via a foam oil ring is essentially the same for all mfrs, why should eg Fox recommend 85wt (Fox Float Fluid is apparently equiv to this wt) on the foam ring , 7.5wt on the oil bath and RS go for just 15wt throughout? Won`t the Fox foam ring end up just as a 7.5wt soaked ring with use,?? :? :?

supersonic

The bushings may be grooved, different materials, different tightness.

The oil bath has to move about, and sometimes there are small ports for it to move through.

Basically the systems are optimised to work with certain weight fluids.

You would probably be fine with 5wt in the RS lube areas, but having had the forks apart many times, you can see 15wt is thicker and seems to stick around the o rings better too.

JamesB

Fair enough, thanks

snotty badger

When I checked the RS manual for my Pikes it states 5wt up top and 5, 10 or 15wt in the lowers. It does say 15wt is stock though...

cavegiant

I have changed dampener oils on a few forks to tune to my particular preference.

I am unsure of the particulars of your dampening systems and if the fancy RS offerings needs to be 5 for a specific reason.

I generally run by the motor cycle tuning systems of use the lightest oil you can get away with.

I have a table of relative viscocities from different brands which I can't seem to attach...brilliant.


Anyway, take apart your dampener and work out how it works, what fluid rates do to particular parts, before changing.

or just do it by each, change weight, see if you like what it does.

On my Dorado, it comes with .
I tried 2.5 but that stopped it working (no appreciable dampening of any kind)
with a mix of the two the fork became a lot smoother and more supple, win!

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cavegiant

dorado came with 5, not sure why that got cut off.


PM me with your e-mail if you want the chart (do not assume that 5wt from one manufacturer is even close to 5wt from another).

Super is however spot of for the fork lube, use what it says, nothing else.

Don't use this on your chain.