Archived Posts

Post by **Admin** » Mon Apr 16, 2007 6:14 pm

I personally dont like ATF for any application in rear shocks or forks, i find its too "edgy" and offers no real lubing properties.
Bel Ray make fork and shock oil in various viscosities which offer superior performance to ATF or regular oil.
For years ive used this in all my motocross bikes with no seal leakage or noticable wear, also you can play around with the viscosity grades to alter the rebound and damping properties, especially useful on forks that dont carry any external adjustments.

Post by **Admin** » Mon Apr 16, 2007 6:18 pm

Allan, what weight works well in the GT750? Like I said, I've never really gotten a feel for fork oil, so I've just stayed with the ATF. My forks have the damper mods.

Lane

Post by **Admin** » Mon Apr 16, 2007 6:23 pm

160cc (5.4 ounces).

Lane

Post by **Admin** » Mon Apr 16, 2007 6:38 pm

Lane do you have the CC volume for all the various ft forks thru the years for the buffalo, or is the 160ccs covering all the models J to B.

Post by **Admin** » Mon Apr 16, 2007 7:18 pm

Good question on the oil viscosity needed for the buffalo Lane,and until i rebuild and test the A model forks i have, i cant tell you this final figure yet.
Looking at the ATFs viscosity i'd say that the minimum fork oil to even consider in the Buffalo is the 7 weight, although i think the 10 would hardly be way too stiff either, considering the overall soft nature of vintage forks with very little in terms of proper damping.
This general spongy performance was commonly called the "pogo stick" effect back in the days of when testing these bikes.
For my A model forks i still need to get my new upper stancions which will soon be here, some new piston rings for the lower inner rods and paint the alloy outer legs in a decent metallic silver with clearcoat.
I cant stress enough that its a common myth, that by raising the oil level significantly the overall hydraulic action will stiffen up.
Definately it will for a while till you over pressurise the system internally and 'blow' the seals, then its back to another rebuild.
I also have some progressivily wound fork springs to add into the mix, so these will also affect the overall compression and rebound damping action along with me playing with the viscosity values.
I had heard about the mod with blocking some hole recently, but havent persued it, so which hole are they referring to.

Post by **Admin** » Mon Apr 16, 2007 7:24 pm

I agree that increasing the oil quantity won't affect damping, but it sure will increase the rising rate of the air spring effect near bottoming, which sometimes will make the fork seem stiffer.
Jr.

Post by **Admin** » Mon Apr 16, 2007 8:39 pm

The mod is posted on the resource page (I think, Muzza's site for sure), but it's really simple. You plug one of the two holes at the top of the damper rod. This doubles the rebound damping. I use acid-core solder and a propane torch to do it. My forks don't pogo anymore since doing it.

Lane

Post by **Admin** » Mon Apr 16, 2007 8:43 pm

According to Mr Clymer, the J and K models used 235cc (7.9 oz). All others, 160cc.

Lane

Post by **Admin** » Mon Apr 16, 2007 8:54 pm

OK i got the plan with blocking one of the damper rod bleed holes,and yup that would be one way to slow the damping action for sure.

Post by **Admin** » Tue Apr 17, 2007 4:54 am

Thanks for the info, that is great I can button up the front end. Thanks again Mac

Post by **Admin** » Tue Apr 17, 2007 12:06 pm

One rule of thumb for all standard type front forks is, you want to take a look down the tube. With the lower leg slider filled with oil, fork fullly extended, you want one inch of fluid above the top of the damper. The damper is that aprt the spring sits in, and the part you can see in the center of the tube.

Oil gets pushed up into the spring, and doesn't drain down as fast as we think, so...the oil level needs to be high enough to not uncover the top of the damper.

Post by **Admin** » Tue May 01, 2007 5:29 pm

i did my fork seals today. it's amazing how much crap gets in there in one season. while i had it apart i braised the top orifice. i read somewhere that there is three orifi but mine only had two. i braised it anyway but now i'm wondering if i shouldn't have. the front end felt really washy last summer so it should be better but i don't want to pop the new seals. any comments?

Post by **Admin** » Tue May 01, 2007 5:51 pm

Advant,

The article is here:

http://www.ozebook.com/compendium/suzi/mags/forks.htm

and the info you want is here:

http://www.ozebook.com/compendium/suzi/mags/forks2b.jpg

There should be two rebound damping holes at the top that you reduce to one and one compression damping hole at the bottom that you leave alone. Don't forget the 1 inch spacer between the damper rod and the cone at the bottom.

Jim

Post by **Admin** » Tue May 01, 2007 6:15 pm

for lack of the proper length allen bolts i put the spacer mod on hold. it will be a good test bed though to see how the front end reacts doing the mods in stages. if the spacer lifts the damper rod (as well as compressing the spring) does that mean more fork oil is required to cover the damper rod?

Post by **Admin** » Wed May 02, 2007 12:57 am

I haven't altered the bottom hole on any I've done. You've done well; it'll work fine. I added the spacer to one set of forks, and honestly haven't noticed any significant difference from the added travel. Maybe if I start jumping the bike, it'll matter...... I've done two sets without the added spacer.

Lane

Archived Posts

Fork oil

damper rod mod