Fork Oil

[RichV]

I live out in the country and the nearest place that sells fork oil is a long ways off. Is there something else I can use that's a good or better replacement? I've heard of using ATF as a replacement.

[bikerphil]

ATF can be used in a pinch, it is lighter weight than 10W, more like 5W. I have tried it, but have always switched back to a heavier fork specific oil.

[jetmechmarty]

+1. ATF works, but there's better stuff now. How can you tune the suspension if you don't know the viscosity of the oil? There are several kinds of ATF and each has a different viscosity.

[mlew]

I have used ATF also and it works well. You can order fork oil from amazon and have it in a few days.

[somesuch]

ATF and gold valve would work good together....you really should get some sort of a"gold valve" for the bike...unless you switch to a modern fork.

[motoman]

I live out in the country and the nearest place that sells fork oil is a long ways off. Is there something else I can use that's a good or better replacement? I've heard of using ATF as a replacement.

I'd advise going with Silcolene 15w or BelRay as a second choice. ATF does NOT compress for compression dampening correctly.

[motoman]

I'd advise going with Silcolene 15w or BelRay as a second choice. ATF does NOT compress for compression dampening correctly.

BTW, same removal process goes for middle drive and final drive filler caps in order to release them.

[TopCatGr58]

I'd advise going with Silcolene 15w or BelRay as a second choice. ATF does NOT compress for compression dampening correctly.

Hey Brant,

Just wanting to discuss physics here. From what I learned in school....liquids don't compress! Now with the compression dampening affect of the forks, I thought the fork oil had to go thru the small ports in the dampening rod, and that it was the viscosity of the fluid that controlled how quickly the fluid would pass thru those holes, and therefore how soft or firm the compression would feel dependent on how thick the fluid was. The higher the viscosity, the slower it would flow thru the holes and the stiffer the dampening/compression would feel. The thinner, the quicker it flows and the softer the compression would feel. This discussion is more for newbies and such, I know YOU know these fluid dynamics properties.

I use ATF, Dexron III, I found that the viscosity is similar to 15wt fork oil. It also has antifoaming properties, as well as detergent properties. YMMV.

T.C.

[jetmechmarty]

With damper rod forks, everything is a compromise. If you use heavier fork oil, high speed damping (hitting a bump) suffers. Lighter viscosity may mean low speed damping (encountering a dip in the pavement) won't work as well. If you wish to play with it, stick with one brand of fork oil as viscosity varies between brands.

[motoman]

With damper rod forks, everything is a compromise. If you use heavier fork oil, high speed damping (hitting a bump) suffers. Lighter viscosity may mean low speed damping (encountering a dip in the pavement) won't work as well. If you wish to play with it, stick with one brand of fork oil as viscosity varies between brands.

Very true Marty, as far as brand differences. Thanks for the full explanation T.C. I've gotten real lazy with full explations. ATF, whether it be DexronIII or whatever STILL doesn't have the designed dampening affects going thru the orfices, but would use it myself 'in a pinch' if I didn't have easy access to correct specific fork oil. Problem with older fork orfices is with extended use with age, the reccomended fork oil weight NEEDS to be stepped up in weight from original factory reccomendations. Reason being is orfices getting slightly enlarged from oil friction. Not to defer from subject, but my moto-dross bike forks would get so hot from competative racing they were to hot to touch after a moto heat race. Heat IS from oil friction through orfices.