Anyone try 2.5wt damper oil in Rockshox Forks? (factory is 5wt)

[Skylark]

But within reason you'd want less low speed compression damping for better small bump compliance, so lighter oil would be better in that regard?

But it's 6 of one half a dozen of another because you could put a little more negative air pressure to compensate for using heavier oil?

[Cassie]

And how about mixing two types of weight oil (say (10wt & 5wt) to get to soemthing in-between?

I think this topic was covered many moons ago...but i'm sure Lefty / Droo will have a good answer??

[droo]

And how about mixing two types of weight oil (say (10wt & 5wt) to get to soemthing in-between?

I think this topic was covered many moons ago...but i'm sure Lefty / Droo will have a good answer??

 

You can, but with the range of oils available off the shelf it's unnecessary. If you are going to blend, 2 things - one, stick with the same maufacturer and range, and secondly use the ISO viscosity in cSt, not the weight on the front of the bottle.

 

Link to an online blend viscosity calculator that takes out all the HG maths. The formula is logarithmic, not linear, so equal parts 10 and 20 cSt will not give you 15 - you'll need 39% 10 and 61% 20.

 

If you're up for some reading about LSC, including some intimidating looking formulae, click here. There's also a list of the ISO viscosities of most commercially available oils at the bottom.

Edited March 6, 2014 by droo

[Cassie]

Your'e the man!!

 

I'll read this for interest sake...But it's much easier to just buy the correct Wt oil fromthe start..and concentrate on the job at hand i.e servicing the fork!!

 

Much appreciated for the info...

[GoLefty!!]

You can, but with the range of oils available off the shelf it's unnecessary. If you are going to blend, 2 things - one, stick with the same maufacturer and range, and secondly use the ISO viscosity in cSt, not the weight on the front of the bottle.

 

Link to an online blend viscosity calculator that takes out all the HG maths. The formula is logarithmic, not linear, so equal parts 10 and 20 cSt will not give you 15 - you'll need 39% 10 and 61% 20.

 

If you're up for some reading about LSC, including some intimidating looking formulae, click here. There's also a list of the ISO viscosities of most commercially available oils at the bottom.

 

 

Just remember that the formula assumes that the VI of the oils is the same or similar and that both oils are of mineral composition. It will get you close enough for the purpose of blending your own oil.

 

So when mixing two oils, try to get both oils from the same manufacturer with a very similar VI: within 10% is good enough.

[Pipsqueak]

I was alarmed when I took my Revelation apart - how little (or no) oil there is in there from new. None in the air chamber (solo), just a blob of grease, and literally a smear in either side (apart from damper). Having dealt with Fox before I can't figure out how RS expect things to keep working for that long, unless that's part of the plan.

 

Surely I can put a little more than 5ml in?

[droo]

I was alarmed when I took my Revelation apart - how little (or no) oil there is in there from new. None in the air chamber (solo), just a blob of grease, and literally a smear in either side (apart from damper). Having dealt with Fox before I can't figure out how RS expect things to keep working for that long, unless that's part of the plan.

 

Surely I can put a little more than 5ml in?

 

Considering they last a whole lot longer on average than Fox, I don't think there's much of a problem with what they've got in there. You can run up to 10ml bath oil per leg, but it'll just leak past the wipers faster.

[Pipsqueak]

Considering they last a whole lot longer on average than Fox, I don't think there's much of a problem with what they've got in there. You can run up to 10ml bath oil per leg, but it'll just leak past the wipers faster.

OK, interesting. Tx.

[Skylark]

Ok so I used that Yamaha fork oil, couldn't get the cST specs of the actual bottle I got as I'm not sure it matches the yamalube 5 oil on those fork oil weight lists floating around the internet. It says SAE 5 on the bottle though, its weird, Yamaha has it on the website but no cST weight or specsheet?

 

 

Fork is noticeably plusher now though, its awesome, rebuilt it with hydraulic O-rings from SKF (cost R20 for 2 full sets for rebuilding the damper and dual air sides), what a winner - my fork is so easy to work on! (Finding the 100% correct O-ring sizes though was a f0kking mission, if you try be careful as they use a mix of metric and imperial oring sizes)

 

This is the oil, anyone use it before or know the cST weight of it:

 

 

Edited March 17, 2014 by Skylark

[Super_mil]

Fork is noticeably plusher now though, its awesome, rebuilt it with hydraulic O-rings from SKF (cost R20 for 2 full sets for rebuilding the damper and dual air sides), what a winner - my fork is so easy to work on! (Finding the 100% correct O-ring sizes though was a f0kking mission, if you try be careful as they use a mix of metric and imperial oring sizes)

 

 

Did you just take the O-rings into SKF with you or how did you go about measuring them?

[Skylark]

Searched on the internet, was a long mission as there were lots of conflicting peoples opinions , eventually I found a thread with a lot of people confirming the correct sizes in imperial and mm for my specific 2009 Revelation . Lots of people tried measuring them in mm and getting the equivalent metric size if it was imperial size they measured, that does not work!

 

If you go to an SKF with the O rings taken from your fork or you buy an original seal kit and take to with you they will be able to match them up but the guy helping you better be patient but then again when mechanics rebuild hydraulic equipment that's what they probably do.

 

I put the rings out of the fork on a screw driver shaft and hung each one next to the new one from SKF, they will match almost perfectly in all respects. Although they may be just slightly different due to wear and getting stretched, when you install them you can also feel the slight friction increase relative to the old worn ring.

 

O rings are measured by the ID and ring thickness, there may be a few different thicknesses of each ID size in metric or imperial but there's not a whole lot of room for error if you are careful as they jump by about 0.5mm per sizing so as long as you careful it works. A vernier helps, possibly indispensable.

 

Maybe Droo if he's feeling charitable can help out with Oring sizes, we must start a fork/shock seal size sticky, man I struggled to get the correct Orings, was a huge learning curve , especially finding out some of the seals were imperial.

Edited March 17, 2014 by Skylark

[droo]

Step one: get a vernier. Any other way of measuring will be a waste of time. Even one of those crappy plastic ones from Builders will do, just don't leave it in the sun.

 

The trick with metric and imperial sizing - measure the cross section first. Metric start at 1.0 and go up in 0.5mm increments (with a few odd ones thrown in to piss you off, like 1,3).

 

Imperial: 0 series 1.78mm, 1 series 2.62mm, .2 series 3.53mm, 3 series 5.33mm.

 

A quick google will throw up an imperial size chart which helps a whole stack when measuring ID.

 

As for my database - I've spent the last 18 months collecting kit specs for a million different forks, but they're all in a little notebook. If someone feels like capturing all the data for me I may be inclined to share it, but the current format works for me and I don't feel like generating more work for myself

 

Last one - that friction increase is because you should be lubricating the o-rings before installing them. Float fluid or a soluble grease like Motorex Prep M or Parker O-lube will do the job, although if you've just rebuilt your air spring you should have something that works.

[PhilipV]

hmmm, I have a rebuild kit that is still in a sealed packet.

 

Question to Droo: Can I get the different seals, foam rings, crush washers and O-rings from non traditional suppliers (like Bearing man etc?) My hope is that this will be cheaper than buying a RS service kit everytime. Will this be detrimental to the health of my fork?

 

Then I think I should open the packet, get the corresponding sizes and specs for my kit, and we can create a thread with this. Mine is the Rockshox 32mm stanchion kit for the 2012 SID (26er)

[droo]

Wipers and foam rings are proprietary, but Rockshox kits aren't that pricey. Where you'll battle is crush washers (I have literally thousands, so just ping me if you need) and glide rings (which almost never need replacing).

 

The o-ring kits are standard on almost all 32mm RS forks, and are all standard sizes available from any decent o-ring supplier. Just take the current kit along - they'll measure for you - and keep the receipt for the order codes.

[Super_mil]

Searched on the internet, was a long mission as there were lots of conflicting peoples opinions , eventually I found a thread with a lot of people confirming the correct sizes in imperial and mm for my specific 2009 Revelation . Lots of people tried measuring them in mm and getting the equivalent metric size if it was imperial size they measured, that does not work!

 

If you go to an SKF with the O rings taken from your fork or you buy an original seal kit and take to with you they will be able to match them up but the guy helping you better be patient but then again when mechanics rebuild hydraulic equipment that's what they probably do.

 

I put the rings out of the fork on a screw driver shaft and hung each one next to the new one from SKF, they will match almost perfectly in all respects. Although they may be just slightly different due to wear and getting stretched, when you install them you can also feel the slight friction increase relative to the old worn ring.

 

O rings are measured by the ID and ring thickness, there may be a few different thicknesses of each ID size in metric or imperial but there's not a whole lot of room for error if you are careful as they jump by about 0.5mm per sizing so as long as you careful it works. A vernier helps, possibly indispensable.

 

Maybe Droo if he's feeling charitable can help out with Oring sizes, we must start a fork/shock seal size sticky, man I struggled to get the correct Orings, was a huge learning curve , especially finding out some of the seals were imperial.

Step one: get a vernier. Any other way of measuring will be a waste of time. Even one of those crappy plastic ones from Builders will do, just don't leave it in the sun.

 

The trick with metric and imperial sizing - measure the cross section first. Metric start at 1.0 and go up in 0.5mm increments (with a few odd ones thrown in to piss you off, like 1,3).

 

Imperial: 0 series 1.78mm, 1 series 2.62mm, .2 series 3.53mm, 3 series 5.33mm.

 

A quick google will throw up an imperial size chart which helps a whole stack when measuring ID.

 

As for my database - I've spent the last 18 months collecting kit specs for a million different forks, but they're all in a little notebook. If someone feels like capturing all the data for me I may be inclined to share it, but the current format works for me and I don't feel like generating more work for myself

 

Last one - that friction increase is because you should be lubricating the o-rings before installing them. Float fluid or a soluble grease like Motorex Prep M or Parker O-lube will do the job, although if you've just rebuilt your air spring you should have something that works.

 

Thanks guys that is some really good info right there.

I also searched about for O-rings sometime back and found some good info <<here>>

Well that page links to 3 other pages with all the info...

[G00SE]

Good thread this, some nice useful info.