1990 Rocky Mountain Cirrus...

Would be interested to know if you'll hit the same issue than me with the front derailleur [1]. Since yours is the collar band version, there's hope.
 
Would be interested to know if you'll hit the same issue than me with the front derailleur [1]. Since yours is the collar band version, there's hope.
I dont think that your problem comes from FD, more from the BB spindle length... I'm waiting my crankset but for what I saw I'll go with a 122.5 BB... About FD band style I've no idea. I've see some Cirrus builds with each version. Maybe you can ask Synlos, his Cirrus build use a classic collar version. I let you know later when I would have received the missing parts... ;)
 
My Cirrus has a ø31,8mm FD-clamp and a 27,0 seat post. Pre 30,4mm. ;)
I just installed that one, like Shimanos guid says. And thats it...
 
I've gone steerer cable stop on mine as the syncros didnt have the noodle. Made my own Syncros seat post QR after filing and drilling
 
I too have seen Cirrus with both styles of FD. And generally, the band style FD was for the early Cirrus. On mine, even with 127.5mm spindle and despite getting 47.5mm chainline, the cable is still slightly sliding against the derailleur body [1]. But the front gears are operating fine with it. Should I go even wider? I don't know if the BB-UN71 bottom bracket was available with a spindle longer than 127.5mm.
 
Last edited:
With early 90s XT 122.5 should give 47. 5 (well 89 model+ at least) and 127.5 give the wider 50mm.
Technically back then it was just 122.5 (D-NL) as the spec.


You'd generally (some rule of thumb) use the wider one with the big band, if you had the middle band you'd see which worked for you. Shortest first.

If you have 47.5 chainline with 127.5, then just go wider to get the 50mm chainline.
If it shifts and works well, job done.
Don't worry why the crank might be out, worn tapers etc..
 
Back
Top