New Project, "The Fat Girl"

[crazy steve]

...Issue we still have is the left fork tube. We replaced both seals on the forks but the roughness of the left tube destroyed the new seal in 100 miles. I have a good set of air forks from a 81 special in the parts pile. I know the preload adjuster and air fittings are different between the 2 bikes but can I swap over just the tubes?

Fork Diameter and 'working' length is the same on all the XS/XJs, but the fork geometry isn't, as well as having different internals. All special/XJ forks will interchange, as well as all standard forks, just don't mix and match; swap the whole works (trees, etc) if you do (unless you're running a sidehack, then there's a legit reason for mixing).

'78E original owner

[wingnut]

Steve I was just thinking of taking the guts out of the XJ tube and installing them in the replacement tube from the XS. I have to disassemble the XJ tube assembly anyway to replace the seals so I'll have a look and see if the guts will fit. The rebound adjustment and the air fill parts are different but the XJ parts may screw into the XS tube. I'll let you know. If not we will be looking for an XJ tube

[crazy steve]

...I was just thinking of taking the guts out of the XJ tube and installing them in the replacement tube from the XS...

If the 'replacement' forks you have are off a special, it should work, and there may not be any difference internally. In fact, the special and XJ forks may be the same. If they're 'standard' forks, no way; the tubes are different lengths, and they're machined just enough differently that the internals won't quite fit.

'78E original owner