[Stromper]

Any one add shraeder valves to the fork caps and run air pressure in the forks



I am probably like 230 plus when suited up so almost sureadly beyond spring design



I would think like 10 psi would stiffen them up some



Also reading the fork oil threads and being lazy would like

120 MM oil height be a good bet to start rather than the 135 specified

for us lazy and not so picky people ?



Like 120mm of 7.5 weight oil mostly trail performance

Comments?

 

[lizrdbrth]

Interesting true fact:



Fork shraders were never intended to be used to ADD air to a fork. They were intended to let air OUT of them at will.



That said, plenty of people use them that way. 10 psi is a lot, and combined with the high oil levels it might guaranty blown seals. If you're going to use air you prolly should go with 135 and hope for the best.



Early YZ80's and YZ125's with 33mm tubes have shraders and will directly replace TW top caps.

 

[Rainman]

Any one add shraeder valves to the fork caps and run air pressure in the forks



I am probably like 230 plus when suited up so almost sureadly beyond spring design



I would think like 10 psi would stiffen them up some



Also reading the fork oil threads and being lazy would like

120 MM oil height be a good bet to start rather than the 135 specified

for us lazy and not so picky people ?



Like 120mm of 7.5 weight oil mostly trail performance

Comments?

250 plus gear here and its once in a blue moon when I bottom out the front forks. Obviously, if you don't stand up or are jumping it they will bottom out.

 

[dganey]

Thanks to Lizrdbrths insight, I obtained and added the 1982 YZ80 top caps with shrader valves. I run 1 to 2PSI-cold (non-use measurement). however i also added the hyperpro pregressieve springs (spacer cut a little longer for extra preload) and ATF fluid. I am 235 and the front end works great with very little diving on hard breaking. The springs along with modest air pressure have really made a big difference in the front end. It will be an automatic for my next tw as well. By the way, it is really easy to do--did it all without removing the fork tubes.



Dusty

 

[GapRunr]

however i also added the hyperpro pregressieve springs

Hey Dusty,



Do you still have a part number for the HyperPro springs?

 

[Rainman]

Thanks to Lizrdbrths insight, I obtained and added the 1982 YZ80 top caps with shrader valves. I run 1 to 2PSI-cold (non-use measurement). however i also added the hyperpro pregressieve springs (spacer cut a little longer for extra preload) and ATF fluid. I am 235 and the front end works great with very little diving on hard breaking. The springs along with modest air pressure have really made a big difference in the front end. It will be an automatic for my next tw as well. By the way, it is really easy to do--did it all without removing the fork tubes.



Dusty

Hmmm...interesting. You have sparked my interest.

 

[n2o2diver]

Shouldn't you use nitrogen? Compressed air has moisture that would cause corrosion, not to mention contaminate the fluid. FWIW

 

[qwerty]

Shouldn't you use nitrogen? Compressed air has moisture that would cause corrosion, not to mention contaminate the fluid. FWIW

I have one branch of my shop air system routed through a filter, water separator, and resin dryer used for spray painting. I use this branch for inflating tires and air shocks.

 

[dganey]

Hey Dusty,



Do you still have a part number for the HyperPro springs?

Hyperpro part number: SP-YA01 SSA 003: Listed for the TW125, but same for TW200,225. Go to Yamaha section at end of the PDF--3rd from top of yamaha section. Purchased through http:

http://www.epmperf.com/price-lists/Springs 02-12.pdf



//www.epmperf.com/

 

[dganey]

I have one branch of my shop air system routed through a filter, water separator, and resin dryer used for spray painting. I use this branch for inflating tires and air shocks.

+1 on the filter/separator.

 

[rockpile]

Stromper,

I drilled and tapped my caps and installed some valves. At first I tried 10 psi and after the first ride the seals blew out. (the seals were 16 years old) After replacing the seals I added 7.5wt oil and added a 1" pvc pipe for preload with 6psi. The ride was much better but the real rocky parts made the front dance around a lot. I put in 1/2" pvc and its better for the rocks but still bottoms on the faster sections of the trail. I'll take the bottoming out over the pogo stick every day. I use the air pump off my Harley to set the forks before each ride. I can keep up the Pachaug crew with this set up but the bike lets me know its not happy with the pace they ride at.

 

[Stromper]

I'm in Baltic, CT

 

[rockpile]

I'm in Baltic, CT

We rode the loop together last year. It was the time your bike fell off the back of your van. I still have to swap motors and replace the broken spokes on my other rim with the duro tire on it before I'm ready to head back out. I'm up for rides after work (4-5) during the week after I get things going agian. Drop me a line I know pachaug and all hard and easy lines through it.