Strange things in my forks

[Hafty]

ok, I bought some 2003 CRF450R Showa forks through ebay.  They are for a XR650L which I am rebuilding and converting to USD.   Everything looked good on the outside.  The left leaked a bit, so i figured it was a good time to rebuild them and learn how to do a revalve. Anyway here is what I found inside.

 

The top is the right set of valves,  the bottom the left.  You can see that the left rebound stack has more spacers to fill out the shaft.  And the old parts on the wire are different than the right.

 

Notice photo two.  The rebound shafts are different lengths.  I was wondering why I had left over brushings and O-rings from the kit.

 

 

 

 

 

 

 

I found some matching compression parts on ebay and I'll get those, but what the heck do I about the rebound shafts or does it matter that they are different?  And I guess its the threaded end where the valves/pistons bolt on.that's different. 

 

BTW this is the first set of shocks that I have worked on.  I'm glad that Race Tech gives you a good place to start with their gear.

 

What the hell did I end up with?

 

Mark

Edited May 5, 2015 by Hafty

[chadk66]

you ended up with a smorgasborg of parts lol.   different length rebound rods is bad.  dude that is messed up.

[Hafty]

I found a compression bolt set up on eBay that I hope will match my cartridges, and noted a couple of other things about the rebound shafts.  They are from the same model and year fork, but with what I have found... who knows.

 

When I line up the bottom end of the shafts the top out ends are ~5mm different. But I put the rebound shafts back in the cartridges and extended them to full length.   They both extend out the bottom of the cartridge 12 27/32" Which leads me to believe that the travel in both sides is the same.

These forks are going to be used in a USD conversion onto a XR650L.  In my research I have been told that I need to lower the CRF forks to match the travel length of the xrls original forks ~.8 inches.   I found an article on Super moto junkie where it looked like a guy used what he discribed as plastic tubing that he got at home depot or some place like that. Look here post #86

 

Is that possible or do I need to find something that will tolerate heat better? 
Will adding an ~.8" spacer to the rebound top out be too much of a preoad to the spring?
Do I need to cut the spring to compensate for the added preload cresated by spacer?  There are couple of things mentioned in the above super moto post that make it sound like I may not need to do that for this short of a spacer.

 

Thanks for any help

Mark

Edited May 10, 2015 by Hafty

[russ17]

ok, I bought some 2003 CRF450R Showa forks through ebay.  They are for a XR650L which I am rebuilding and converting to USD.   Everything looked good on the outside.  The left leaked a bit, so i figured it was a good time to rebuild them and learn how to do a revalve. Anyway here is what I found inside.

 

The top is the right set of valves,  the bottom the left.  You can see that the left rebound stack has more spacers to fill out the shaft.  And the old parts on the wire are different than the right.

 

Notice photo two.  The rebound shafts are different lengths.  I was wondering why I had left over brushings and O-rings from the kit.

 

 

 

 

 

 

 

I found some matching compression parts on ebay and I'll get those, but what the heck do I about the rebound shafts or does it matter that they are different?  And I guess its the threaded end where the valves/pistons bolt on.that's different. 

 

BTW this is the first set of shocks that I have worked on.  I'm glad that Race Tech gives you a good place to start with their gear.

 

What the hell did I end up with?

 

Mark

you have 2 different year forks. 1 is probably as you said 03 but the other looks like a 08. different rod lengths different floating pistons different mid pistons

[Hafty]

you have 2 different year forks. 1 is probably as you said 03 but the other looks like a 08. different rod lengths different floating pistons different mid pistons

 

I kind of tend to agree.  I can find the right leg floating piston in a parts fiche for the 2003.  The ones I bought to replace them are from a 2003 according to the guy that I bought them from, and look like the right leg parts.  All of the rebuild parts in the kit matched the right leg.  

 

I can't find the left leg parts any where.   There is nothing like it in the parts fiches.  Its like somebody mixed and matched a couple of forks into the 2003 body on the left.  To remove the valve piston and shim stacks I had to file the bolt/nut on all of them like they were factory installs.  Its like they swapped stock parts around trying to make someting work.

 

I measured the extended length of each cartridge with the rebound rods installed and they vary in length by ~3/8"  The right is longer.  I'm really not sure what to do about this.  ? 

 

Since I am lowering the forks so they match the geometry of the XR650L, I'm thinking I can make it up with the lowering spacers?  Any thoughts about that and the supermoto junkie link above and using PVC pipe as the spacers.

 

Any possibility of rescuing this nightmare at all?

 

I appriciate any help/input you guys can share.

 

Thanks

 

Mark

Edited May 10, 2015 by Hafty

[Clicked]

Since you are lowering your bike anyway the different rod lengths aren't going to make a difference. Just make sure both forks bottom and top out at the same stroke length.

 

The valves in your photo are RaceTech valves except for the one base valve. You need to get another RaceTech base valve so it is compatible with the mid-valve you have. RaceTech can probably help you out with a shim stack recommendation for the conversion as well - figure that out before you order the new base valve.

[Hafty]

Since you are lowering your bike anyway the different rod lengths aren't going to make a difference. Just make sure both forks bottom and top out at the same stroke length.

 

The valves in your photo are RaceTech valves except for the one base valve. You need to get another RaceTech base valve so it is compatible with the mid-valve you have. RaceTech can probably help you out with a shim stack recommendation for the conversion as well - figure that out before you order the new base valve.

Thanks for the reply.  This will really help me out.  I bought the RT valves and was in mid upgrade when I found the issues.   I pulled the completed one apart to see what was up.  Then started asking questions here.  

 

I bought these so I would have matching compression assemblies, and modified them with the gold valves.   RT has been great to deal with for me. I contacted them and talked to Kelly I believe and he set me up with how I should go about setting up my valve stack for the heavier bike.

 

So is PVC pipe from the local home depot something I can work with for spacers, Or will they melt?   So far I have not found any really definitive answers.

 

Clicked, I have been following the Shim restackor thread you have going here.  Great stuff.  I have been learning a lot. I'll have to reread it several times to digest it all.

 

Again thanks for the tips.

 

Mark

[mastera210]

HATE to tell you this but if one is 03 and one is a 08 the offset at axle is moved in 3mm I think On the 08

[Hafty]

HATE to tell you this but if one is 03 and one is a 08 the offset at axle is moved in 3mm I think On the 08

The offset you are referring to would be measured from the center of the axle to the center line of the inner fork tube?

I'll check it but I think the outer parts are the 2003. It's the inner ones that have been messed with. I think the compression assembly in the left fork is from something older than 2003. Maybe a CR model. I can't find one with that style of floating piston in the parts fiche that looks like the left one. The right compression assembly matches the two I just bought that are confirmed to come from an 03 model fork

Thanks for the help

Mark