Chainline question...

[a4racer]

Ahoy all,

Looking to switch my drivetrain up a bit.

Currently riding a 6800 group (mech / hydro disc) on a Trek Boone, 11-25 DA cassette.

Looking to go a bit weirder for the winter (which, on Vancouver Island just means "wetter"). Thinking 1x.

After seeing the ad by EddieF here on the classified, I got to thinking: XTR mech, 11-40 cassette, Tampan adapter and XTR crankset (1x11) might be fun. It was pointed out to me by a buddy that the chainline might be an issue.

Currently, chainline on Ultegra is 43.5mm (assume that is average measure, inner would be 41mm outer 46mm). XTR would be 50.4mm. Is the 6.9mm average difference significant? I know, I could just run my Ultegra crankset with a single ring, on the XTR mech / cassette, but I feel that the XTR crankset would be awfully beautiful. I also have a line on XTR calipers that I'm tempted to swap in lieu of the non-series calipers from the Ultegra 6800 group.

I feel that almost 7mm difference in chainline is significant, but I defer to your opinions!

Thanks!

[dddd]

That's a crazy big change in chainline that I am hard-pressed to explain.

Maybe it's the XTR crank being made to PLUS dimensions. As it is, I found the D-A 9010 crankset to be wider than I wanted, even as the chainline was perfect on a 130mm road frame, the left arm was then several mm further outward from the rear rim than was the driveside arm.

The latest MTB cranksets are able to accommodate wider tires with shorter chainstays, but seem needlessly wide outside of those considerations.

I would not be pleased with any more chainline than I already get with any modern 11x2 setup, since these seem to be near the limit of cross-chaining tolerance already, especially with the non-disc 130mm bikes.

[floxy1]

You're trying to put a MTB crank on a cross bike. Am I missing something? MTB going to have a different chainline

[RudAwkning]

I would just get a Sram Force1 or Rival1 crankset. The 43.7mm chainline would be ideal.

[Clancy]

I would just get a Sram Force1 or Rival1 crankset. The 43.7mm chainline would be ideal.

Running a Rival 1 crankset, works perfect, cheap, looks good

Using a Rival rear derailleur, also flawless