I replaced older 8 speed cassette on my Cannondale Trail with new Shimano Deore M6000 10 speed cassette (11-42). But since the axle spacing is of older type, want to get a matching crankset (2x preferred). Any suggestions? Deore M6000 crankset I presently tried, but has chainline issue.

  • What is the chainline issue, and what M6000 - the FC-M6000-3 (triple) and FC-M6000-B2 has a wider chainline than the FC-M6000-2.
    – mattnz
    May 7 '20 at 1:12

You can look up the specs of Shimano cranks here: https://productinfo.shimano.com/#/spec/MTB/Front%20Chainwheel.

The tables give the OLD (over locknut distance) aka rear hub spacing for each crank. Most are for 142 or 148mm.

Many cranks for 142mm rear spacing have a chainline of 48.8mm, which is just over the old standard of 47.5.mm for triple cranks on 135mm spacing, so any of those should be fine. You just want to avoid cranks with chainline of 50mm or or more.


What is the issue with the chainline? The photo I post is an FC-M6000 crankset (34-24t) mounted on a circa 2009 Specialized Rockhopper having a 68mm bottom bracket shell (threaded) and 135mm spacing at the rear dropout. Using the 2.5mm bottom bracket spacers in the correct position for a 68mm shell--thats two on the right side and one on the left between shell and cup--the resulting chainline is just shy of 50mm. I'm using the BB-MT800 external bearing bottom bracket but the BB-52 would work the same. My cassette is 11-36t with the RD-M781(XT) rear derailleur. This set-up is very smooth and did not require any "hacks" to install or function properly. A similar set up is on my 90's era Giant ATX 890 where I have a 10speed triple crankset (FC-M610) in front of a 9speed rear, same specs as far as shell and rear dropout measurements and it, too, works well. I can't imagine a Cannondale not working beautifully with modern 2x10 componentry. enter image description here!

  • I could see my center line (between 28-38 chainrings) is in line with 7th gear in the rear cassette. Could be I did not fit the rear hub properly? But your post really a helps. Will check again. I haven't ridden the bike yet. And the Shimano specification for my crank-set requires 142 mm hub space. I have seen some photos people tried my group set with similar hub space . Thanks for the helpful reply. The specific model is FC-M6000-2 in my case
    – Anand
    Apr 8 '20 at 8:11
  • My model too (M6000-2). I double checked my chainline and it is 50mm to inside of big chainwheel. In Shimano 2x cranksets the big ring sits in what would be the middle position of a triple. You are correct to measure the chainline to the middle of the 2 rings. Should be 48.8mm, though many will offer up that running the exact spec'd chainline isn't necessary if things are working. I prefer right on.
    – Jeff
    Apr 8 '20 at 17:00
  • When I was building this Specialized up, I noticed something interesting. While waiting for the derailleur hangar to arrive, I measured the distance between the dropouts. It was 142mm right on. The correct hangar sits to the inside of the dropout and when it is secured in place, the spacing becomes 135mm, right on. My hubs are set with O.L.D. of 135.
    – Jeff
    Apr 8 '20 at 17:06

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