1994 Stumpjumper FSR Revival - FINISHED 2015-03-25
- Thread starter Seneb
- Start date
dalecooper
Senior Retro Guru
Re:
Nice bike! Good to see that old parts mix well with new parts! Enjoy the ride!
Nice bike! Good to see that old parts mix well with new parts! Enjoy the ride!
Thanks, everyone. After riding it more, and on rougher terrain, I've decided that the springs in the fork are terrible. So much force is required to fight the rebound that it is exhausting and distracting. If I decide to ride it more frequently, I will surely send the fork to Risse for a GEM cartridge install and a bit of other custom work. I have absolutely no regrets on spending the time and money to rebuild the bike!
Thias":1in08dtk said:Did you refill the dampener cartridge of the Judys?
Maybe there is no rebound dampening any more
Would be an easy fix.
No cartridges, just spings. The fork was originally only elastomers, which I ditched over a decade ago when the forks were on a different bike.
Thias
Klein Fan
No. There is a dampener cartridge in those judys, filled with oil. Those start leaking and loosing their oil.
I will search for a pic to show you...
Edit:
There you go:
Upper row: Cartridge housing, sealing ring, spacer, circlip
lower: dampener rod with valve magic. Adjustment screw accessable from the right.
This is the later aluminium version of the dampener. The early judys had a plastic one. Those were not very durable and popped (broke) quite often.
You should separate your judy and inspect your cartridge. Its not that difficult. Take out the inbus-bolts at the lower end, screw them back in a few turns and (carefully) hit them with a soft hammer. Then you will be able to separate the legs. In one of those legs is the dampener, in the other just a rod with some topout rubbers.
To take out the cartridge you just need to remove that circlip that can be seen on my photo above.
(To test try to slide the rod. It should be easy to move in one direction but "resistant" to the other. Shaking it shouldn't make any sounds. If you can hear the oil wobbling - too much air inside. If there is any oil left
)
The cartridge can be separated also. Just pull it apart and be careful about the oil that will come out.
On one side the sealing ring will slide out. To refill you can use automatic transmission fluid, as I did (equals 7WD viscosity) or by 5WD fork oil. To bleed the dampener, there is a very thin inbus screw inside that (hollow) cartridge rod that has to be removed. (That screw is also used to tune the dampening rate later). Then slide the rod all the way in, fill in some oil, so the housing is filled up half. Then move the rod up and down a bit to allow the oil to flow though the valve. Then fill the cartridge to the brim and press the seal into place. Access oil should come out of the screw hole in that rod. Then put the adjuster screw back in and thats it. When putting the fork back together note that one of the two inbus screws has a bore. This is to allow access to the adjustment screw of the dampening cartridge rod.
After refill you may also find, that the sealing rings are leaking. In that case you can replace them with new standard size seals. I have the sizes written somewhere. You can message me if needed and I will search for them.
Hope that helps.
I will search for a pic to show you...
Edit:
There you go:
Upper row: Cartridge housing, sealing ring, spacer, circlip
lower: dampener rod with valve magic. Adjustment screw accessable from the right.
This is the later aluminium version of the dampener. The early judys had a plastic one. Those were not very durable and popped (broke) quite often.
You should separate your judy and inspect your cartridge. Its not that difficult. Take out the inbus-bolts at the lower end, screw them back in a few turns and (carefully) hit them with a soft hammer. Then you will be able to separate the legs. In one of those legs is the dampener, in the other just a rod with some topout rubbers.
To take out the cartridge you just need to remove that circlip that can be seen on my photo above.
(To test try to slide the rod. It should be easy to move in one direction but "resistant" to the other. Shaking it shouldn't make any sounds. If you can hear the oil wobbling - too much air inside. If there is any oil left
)The cartridge can be separated also. Just pull it apart and be careful about the oil that will come out.
On one side the sealing ring will slide out. To refill you can use automatic transmission fluid, as I did (equals 7WD viscosity) or by 5WD fork oil. To bleed the dampener, there is a very thin inbus screw inside that (hollow) cartridge rod that has to be removed. (That screw is also used to tune the dampening rate later). Then slide the rod all the way in, fill in some oil, so the housing is filled up half. Then move the rod up and down a bit to allow the oil to flow though the valve. Then fill the cartridge to the brim and press the seal into place. Access oil should come out of the screw hole in that rod. Then put the adjuster screw back in and thats it. When putting the fork back together note that one of the two inbus screws has a bore. This is to allow access to the adjustment screw of the dampening cartridge rod.
After refill you may also find, that the sealing rings are leaking. In that case you can replace them with new standard size seals. I have the sizes written somewhere. You can message me if needed and I will search for them.
Hope that helps.
