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Discussion Starter #1
What are your recommendations on fork oil? I have a 96 cb750 fyi. I will be doing the whole kit from all balls. Thanks.
 

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atf weorks as good as any
think of it as about a 10 wt
so it aint worth piss if you require 30wt
the only drawback is atf stinks so i use maxima fork oil the shocks i restore ,reasoni mention it is you can get it from multiple sellers on ebay $10 a liter shipped from 5wt to 30and itb smells nice
https://www.ebay.com/itm/Maxima-56901-Fork-Oil-15WT-1L/332423003297?hash=item4d65f47ca1:g:2wgAAOSwy0JZ7iOO
go ahead and spend 25-30 a liter on stuff that works no better if you hate money
bmw riders use knarwhalre semen worksb nom netter,nope
i always try 1wt under what factory manuals have as a guidline dont go on the heavy side it wont cure soft springs

do get the springs dialed in
 

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I'd check over at the SOHC4 forums to see what they like to use. You can't go wrong starting with the recommended weight in the service manual though. I'm a Bel-Ray brand guy myself.
 

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repsol make a 15w30 that seems to work well in damper rod forks. depends if you can get it and what is recommended though.

a quick google found lots of info. 10 wt seems to be the starting point. oil height is a variable you can play with too. the higher the level the more the air spring effect will come in to play. this makes the forks firmer as they get toward full compression. it's amazing how much difference it can make to the way they work under heavy braking or the like.
 

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In the grand scheme of things fork oil is not that expensive. You wont need more than a litre.
i do agree but little overcosts on the bike can soon asdd up to a new tire
if a gal or guy is convinced the fork oil was a bargain then i feel they will be more open to tuning and testing ans learing how to make changhes in careful inkervals
a little spilt/contaminated fluid is not a mental block so much $10 a liter $30 a liter
the 30 will induce more cstress if it gets "wasted"
then again aint nobody gonna learn to =tune there springs and suspension unless theyreally want to and look into it on their own without some asshole like me barking orders
cause what matters most is what turns heads lol you fools aint nobody gonna head turn becausae you been blowin seals
 

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Discussion Starter #7
Now xb if I understand you correctly your saying automatic transmission fluid is as good as the specific fork oil? If viscosity and weight are similar I see no problem with it. I understand different brands may use different additives but imo your looking for a hydro type fluid capable of transferring pressure via side to side cycling correct? If anyone has a food link on how to properly tune the front cylinders that would be great. Thanks again everyone.
 

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ATF is about 7wt. Most of the honda factory service manuals for 1970's motorcycles recommended it because it was cheap, plentiful, and about the same weight as the factory stuff (7.5wt). Personally I run Golden Spectro 10wt fork oil in almost all my old motorcycles. The exception being when I used Motorex synthetic in two of my bikes because the shop was out of GS. Honestly the GS is petroleum and $10 a pop where as the Motorex is almost $20 (I think it's like $18). It's up to you - I don't notice a performance difference between the two, but I am expecting a longevity difference out of the synthetic.
 

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The thing about ATF is you don't know what weight it is.

In this thread alone there are 2 knowledgeable guys who think its either 7 or 10 weight.

Fork oil is sold by weights, so it's really a no brainer.

Plus it's not like engine oil where you change it every thousand miles or so.....and even if you did you only use about 500ml......
 

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OK, so all this stuff is basically hopped up hydraulic oil, so viscosity ratings are semi arbitrarily derived. So, if you are gonna tune with different weight fork oils, stick with the same brand. If you start with one brand of 10w, decide it is not enough, and then buy a different brand 12w, the second brand's 12w may not be any heavier than the first brands 10w. I think I read about this at the RaceTech website, and if so, it is explained much better there.
 

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The thing about ATF is you don't know what weight it is.

In this thread alone there are 2 knowledgeable guys who think its either 7 or 10 weight.
It's funny, but I think the reason that there is a difference is because of heat. The viscosity of oil is measured at a fixed temperature. At about room temp (60-85 degrees F), and depending on the amount of processing and refinement, ATF is about 10wt. At 100 degrees F it can drop down to as low as 7. ATF is meant to be used under pressure in a mildly warm transmission so you don't see as wild a swing in the hotter ranges as you would with something like motor oil that goes from 30wt to 10wt from cold startup to operating temperature. BTW, some transmission fluids have more viscosity cold and are 10wt at 100 degrees F. Which.....

...brings us back to waht Seanbarney41 says above - that viscosity is somewhat arbitrary with ATF and it is not really rated by viscosity so go with the stuff that is and be consistent with it.
 
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