What is the rough chainline on an XCL?
I just finished building my XCL a few minutes ago and was adjusting the derailleurs. When I was in the middle (front) ring and largest (32t) cog the chain would hop onto the small chainring without the front derailleur touching the chain. I measured the chainline and come up with ~54mm, which is a bit on the high side of the ~47mm 'norm' by about 1/4" or so.
One thing which may be contributing to the issue is that I've just installed a middle chainring from my old Truvativ Firex crank onto my old Stylo Team crank. The stylo is on the XCL now. The Firex ring had only two pins and the Stylo four. Also the spacing between chainrings is not even; the middle chainring sits maybe 1-2mm outboard from the center. But that doesn't account for the 6mm discrepancy.
I used the correct BB (68/73 x 118 Gigapipe) for the E-type derailleur so I don't think that's the problem either.
Also when in the small chainring, the bottom of the chain will drag on the derailleur cage in all cogs except the largest (32t). I've adjusted the derailleur to the higher of the two vertical mounts. There seem to be no further adjustments for this issue.
Any recommendations? Thanks for listening!
You sure you got the spacers on your BB and crank spindle right? In the directions I read on the Shimano site the E-type (XT or XTR) should require a 50mm chainline. In my case (and most external BB's for E-type mounting on 73mm BB shells) there are no BB spacers used on the non-drive side and the only drive side BB spacer is the actual E-type mounting ring. That just leaves your crank spindle spacers and I can't remember if TruVativ uses spindle spacers or not.
It's an ISIS drive with no spacers on either side;
the only 'spacer' is the E-type bracket. And I see from a 2004 Truvativ crank manual that a triple Stylo should have a 48.5mm chainline. The manual also lists only 113 mm spindle width whereas an E-type derailleur requires 118mm. Using a 118 should only move each crank out 2.5mm, but adding in the offset from that oddball middle chainring looks like the culprit. Dang, no ride this weekend!
Unless someone has a good (quick) fix, I'll probably have to get a new crank for 118 spindle length. May not be easy since ISIS is becoming harder to find.