What Have You Done To Your Tdm Today?

[wicklamulla]

 

It's an old favourite of bike shops from 'ye good old days' , Honda specified it as standard for their earlier forks.

 

It's produced to an exacting specification, so unlike 10W fork oil, which has a wide variety of viscosities depending on each manufacturer, ATF is more consistent.between batches. It's also seal friendly and resists foaming well. ATF usually has a viscosity of 34Cst, which is about the same as Silkolene 10W

 

I've used it in both fork legs but thought it was still too light for me,so I thought I would try one leg with a very heavy oil which has a viscosity (cSt) of about 70.

 

The extra viscosity in that one leg reduces front end rebound quite a lot. I notice it when coming off the brakes after heavy braking, with thinner oil the front end popped straight up, but with the heavier oil it feels more controlled. The adjuster valve is set to one click from the least resistance setting so it doesn't give too much compression damping. The leg with ATF mostly controls the compression damping with the help of the 30W leg. The fork leg with ATF is set to one click from firmest setting.

 

This might be a setup which works for me due to my heavy weight , 18 stone fully dressed, so it isn't necessarily a formula which works for everyone.

 

I thought i would try it after riding the KTM for a bit, where one leg controls rebound and the other controls compression.

If I mixed the oils then I wouldn't have the very heavy 30W providing good rebound resistance

 

 

 

Here's a list of some fork oils, you can see that between manufacturers, '5W' fork oil can have a range of viscosities, one manufacturers 5W can have the same viscosity as another manufacturers 10W. http://www.mediaturbo.com/clients/marzocchi/forkoilviscosity.html and here... http://www.dynojet.co.za/wp-content/uplo...rk-oil.pdf

 

 

Standard Dexron 3 ATF has a viscosity of 34.1 (Esso Dexron 3 is 37) , Mobil 1 ATF is 34.0 , I think 34 is in the target ranget for ATF, but older 'Type F' ATF has a cSt of 38.1

 

Honda standard 10W fork oil has a viscosity of 35

 

Castrol 10W fork oil has a viscosity of 15

 

Elf Moto Fork Oil 10W has a viscosity of 47 !!!

 

 

 

 

I've read pages of testimony from people using ATF still today, no problems are reported but it isn't considered the best when using cartridge forks for some reason, but our older damper design is appropriate for ATF

 

Obviously you can replace the ATF with a 10W or 15W fork oil if you were to try a split oil weight setup

 

 

interesting,  thanks