DirtPedalerB

Ok I'm looking for some fork oil and I have found my 5wt at a local motoshop, and I have called many shops looking for the 15wt that goes in the air chamber, but noone stocks it. all I can find is 10wt will this work in place of the 15wt ... or do I need the 15???

dminor 

Available online at the Motorcycle Superstore. You can get Bel-Ray for 11.99 or some brand I haven't heard of - - Maxima - - for 7.99 in 15 wt.

https://www.motorcycle-superstore.com...cessories.aspx

They are physically located in Medford, OR, are huge and reputable and a good outfit to order from.

MX South also has Bel-Ray (for a couple dollars more) and is another reputable online:

https://www.mxsouth.com/belray/belray...e-fork-oil.htm

cryptid01

^ thank you for your regional support.

DirtPedalerB

so your saying the 10 weight is a no go? I think it's mainly to seal in the air ,, I found some 20wt at a nother shop would that be better?

dminor 

Not knowing what fork or its internals, I would go with the recommended weight unless you are trying to achieve a specific performance change that going to a different viscosity might bring about.

You can kind-of achieve 15 wt. by mixing 10 wt and 20 wt half/half.

DirtPedalerB

it's a rock shox reba SL 2006 ... dual air the air side calls for the 15, the damper uses 5 and 15 on the lower

dminor 

^^ OK, in reading the service manual (https://www.sram.com/_media/techdocs/...ce%20Guide.pdf), we're talking really small quanities (15cc) -- which is probably just to lube the piston, o-rings, bushings, etc. I think if you don't do 15, I'd error on the side of heavier visocsity (20) to be sure the bushings stay properly lubed. But that is an uneducated guess.

Svr

For the small quantity of oil in the positive air chamber on Fox and Rock Shox forks:

10 weight fork oil will work in a pinch, but will find its way past the piston seal more quickly than 15 or 20 weight. You'll need to check the quantity and condition about twice as often as usual.

DirtPedalerB

well twice as often as never is never right??? anyway after my intense fork oil research I'm going with the 5 and 10 as they are both the same brand (Honda), looking at a viscosity chart I found the viscosity varies a good bit between manufacturers and I don't want to run all around town... one brands 10 may be another brands 5 or 7 (this is probably tainted info as they were all measured a 104 deg F). The belray oil you mentioned registers as heavier than most.

I might need a seal or something , but I'll determine that later .. the right slider with the damper has black rubber that comes out on the stanction after every 20 mile ride.. It's done that since ive had it not sure what it is. I've been hitting the stanctions with finish line red with teflon to combat that.

I just hope I don't break the thing as I've never servied a fork before.. also I'm doing the headset as it has grindies in it, but last time I looked at it I didn't see a way to remove the races, it's a cancreep vp something the ruther with semi cartridge bearings.. I'm probably going to have to degrease it on the bike then hope I can work grease in it.

I feel so cheeto typing this stuff.

DirtPedalerB

on yeah thanks Dminor and SVr for you help .. and thanks gastro for uhmmm errr your support of my obsessive compulsive thread

never

I've been right on a few occasions.

djp2k8

You can definitely mix 10 and 20 to get 15 weight.

Svr

The 10 weight should work for you, but don't be surprised to see oil coming out of the negative chamber when you check the pressure. The thinner oil that migrates past the main piston seal ends up in the negative chamber, then gets forced out through the schrader valve at the bottom of the left leg when a pump is connected. Just something to be aware of.

RIC0

If your a small guy, say less than 165 use 5wt, anything over use 10wt. I use Amsoil 10wt in all my forks, works much better for rebound. I'm an Amsoil synthetic dealer if you want some 10wt, let me know.

dminor 

Except he's not talking the damper side; his question was about the air-chamber side.

DirtPedalerB

https://www.pvdwiki.com/index.php?title=Suspension_Fluid

a sweet chart of the thickness of fork oil.. the oil i bought honda(showa ss8) has a cs(centistrokes) of 36.47 while the rock shox 15W recommended is 42.8 .. the article reports that rock shox fluid is now just rebadged maxima. with a cs of 46 .. so i'm a little thin, but close enough. plus if it does seep around the seal my shock pump will be well lubed.

ed 

Doesn't that make 10w 20?

DirtPedalerB

no the W stands for winter.. 10w20 would be 10 weight at low temps and 20 at high temps .. i think that's how it works.

ed 

It was a joke...supposed to be funny...not taken seriously...like everything else I say.