pretty sure that the redrum that rockshox recomends to use is really nothing more than the transmission fluid that you put in your car or truck.from talking to guys that have done suspension work on dirtbikes and snowmobiles that transmission fluid is 5w oil and is used in certain suspension applications.not sure what marzoochi recommends for replacement in their forks but i used bel-ray 10w fork oil that i bought from the dirt bike shop on my 02 shiver dc and it worked out just fine.i think the cost of 1or2 oz's of redrum is about the same as 1qt of transmission fluid.