Help me ID my triple trees!

[Firerunner]

Here is the story- I purchased a 1981 XS with a shed full of parts. The P.O. had swapped the forks for what appear to be 1980ish XJ650 forks. The wheel is hideous, and doesn't match the stock aluminum rear wheel, and the thing has dual disks from an XJ, running off of a stock 1981 single disk master cylinder, thus reducing the hydraulic pressure by +/- 50%. The worst part is that the axle mounting location is not centered in the forks like the XS forks, but is set to the front of the axis. I imagine that this is due to the XJ's lower rake numbers, to produce some type of decent trail dimension. Since the XS is raked out a bit more, my trail numbers create handling that can only be described as "limousine-like".

In short, I want to ditch the XJ setup and put XS forks with a stock alloy wheel and single disk back on the bike. Here is the complication: as a part of the shed 'o parts, I received two more XS frames and I think three front ends, all in boxes. Since then, I traded a single frame and front end to someone, but I'm not certain that it was the right front end for that frame. IIRC, the spare frames were early 70's. Now, I have two sets of triple trees. I need to figure out if I gave away the triples for my '81, or if one of my sets is right for it. I don't have the parts in front of me right now, but I can take a look as soon as I get home and look at them better. I'd rather figure this out BEFORE I tear the front end off of a running machine!

I can answer more detailed questions when I get home from work, but any pointers would be appreciated in the mean time. That way, when I get home I should be able to look at the parts intelligently. Both sets of forks seem to fit the tubes that I have, and at first glance, they appeared identical. I'm not really sure if they were even the forks from the frames that I have, but they do appear to be XS650 parts.

Thanks in advance- FR

 

[jamesgs4]

from the aura your parts are eminating, I believe they are from a 1976 xs650 standard, that had a black and silver tank, and was owned by a guy in a green sweater.

 

[Firerunner]

Lol, thanks! I will proceed with that in mind. Would this perhaps be the fellow with the Welsh corgi who chewed up the wiring harness?

What I meant to ask, but only implied, was that I'd like to know of any tangible differences in the parts from different years, so that I could identify these ones.

 

[5twins]

Post some pics of what you've got and you'll be more likely to get some answers.

 

[650Skull]

from the aura your parts are eminating, I believe they are from a 1976 xs650 standard, that had a black and silver tank, and was owned by a guy in a green sweater.

........

 

[jamesgs4]

disc brake front ends use the same 34mm tubes from 72-76. From 1977 on, they are 35mm tubes. you do not want to run 34mm tubes in 35mm trees because they might slip up into the trees when you hit a bump, and that would be a nasty crash.

 

[650Skull]

Need pics to identify the forks. to many differences between 72/77

 

[Firerunner]

After doing a bit of research, it seems that 77+ fork tubes have the caliper in the rear and are 35mm. Since these have the caliper in the rear, I must assume that they are 77+ and thus 35mm. The question then, is what year the steering neck length changed.

I think that perhaps it would have been clearer of me to ask, "can anyone list the differences in triple trees and forks through th years?"

 

[5twins]

The '76 34mm forks also had the caliper in the rear, the only year for the 34s that did.

 

[Firerunner]

Ah. Ok, then. Do you know of any other differences between 76 and 77+?

 

[Firerunner]

Iirc, there is a difference in the top of the fork tubes at some point. Anyone know what and when that was?

 

[650Skull]

The best research would be a picture of the forks. As the saying goes, worth a thousand words.

Stays for the guard are on the 76 34mm forks

identifying the forks wont necessarily identify the triple trees

 

[jamesgs4]

After doing a bit of research, it seems that 77+ fork tubes have the caliper in the rear and are 35mm. Since these have the caliper in the rear, I must assume that they are 77+ and thus 35mm. The question then, is what year the steering neck length changed.

I think that perhaps it would have been clearer of me to ask, "can anyone list the differences in triple trees and forks through th years?"

the steering stem is shorter on 70-73 models, 74+ are the same length.