Front Fork Oil Weight?

[Old N' Grumpy]

I am replacing my Roadsters front springs and rear shocks with Progressives. After looking in the owners manual and doing a search (albeit fast) I cannot find the stock front shock oil weight which is what Progressive calls for. Help please.

 

[Triple Trouble]

I believe that stock is 5 wt

 

[rocketjohn]

My book calls for 0 wt albeit a Touring bike. For a Roadster, I think 5wt or even a tad heavier would be better.

 

[Old N' Grumpy]

And I heard 7 so hopefully others will chime in so I can confirm for sure.

 

[rocketjohn]

You have some flexibility in choosing, depending on how you want to tune the ride. My Intruder had 10 wt from the factory and I had to put 20 wt in it to keep the fork from bouncing like a pogo stick.

 

[Old N' Grumpy]

You have some flexibility in choosing, depending on how you want to tune the ride. My Intruder had 10 wt from the factory and I had to put 20 wt in it to keep the fork from bouncing like a pogo stick.

Guess it's not as easy as one size fits all...****!...lol

 

[Jeffrey Cochran]

When I added Progressive springs to my forks I used 7wt fork oil, if my old and feeble memory serves me right stock was 5wt. This is on a 08 Classic . Just as important is the fluid level !

 

[rocketjohn]

Oh! Yes indeed, the level....too much and it will get hydraulic lock, too little and it will get squeaky and foamy and just not work well at all.

 

[Jeffrey Cochran]

Had some time today so looked it up ,

"The oil level specified for Rocket III forks is 89 mm from the upper surface of the fork outer tube, with the fork fUlly compressed. "

"Fill the fork with SAE 5w (or Kayaba KHL15-10 fork oil until the oil level is slightly above the recommended level. Alternatively add 667cc of oil if filling a completely empty fork. "

Hope that helps

 

[Ishrub]

My suspension specialist used a 10w but I forgot to ask the brand.

When I was researching I found that the nominal wt in 'w' is pretty useless as all brands vary in actual viscosity. So finally check for the oil with best match to specs for Kayaba KHL15-10 fork oil and go from there up or down for weight/ride preferance.

Comparative Oil Weights Table - Transmoto

Buying the right oil for your bike is very important as it can effect performance and the amount of wear-and-tear your bike receives. So what oil should you use in your suspension? Most suspension units use approximately a 5Wt (SAE). But, due to the international SAE standard being so loose, one oil company’s 5Wt can be the same viscosity as another’s 7.5Wt.

Here’s a really nerdy table that uses the much tighter Centistoke (Cst) testing scale, so we can compare brands with accuracy. Want to know more about oils, suspension components and your options? Check out www.teknikmotorsport.com

Some more re Street Triple R fork-oil which uses same KHL 15-10 (KAWASAKI KHL-15-10 cSt @ 40C = 15.3 )

KHL 15-10
After "googling" it, that's what i found :
comparative oil weight
motul fork oil blend chart
it seems to be grade 2.5W, which is very light

Street Triple R - fork oil - Triumph Forum: Triumph Rat Motorcycle Forums