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· A wheelist
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Discussion Starter · #1 ·
My CX frame arrived and I'd hoped to use a new/old stock Race Face Turbine triple square taper MTB crankset (running just two rings on the 110 spider). I use one on my MTB with a 107mm axle and 3 rings.

So I put the 107 BB on the CX and the new crankset.

The chainline is awful! It's about 50mm to the middle ring (I'm just using big & mid). From what I know, I need a chainline of about 41mm to that middle ring for a road/CX frame.

The only other shorter BB I can see is a 103 square taper. I doubt that a 103 is going to give me a correct chainline of about 41mm.

Have you any words of wisdom? Can a mtb triple not be used as a CX or road double and have a good chainline?
 

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I don't know if that particular crankset can be made to work or not on your frame. Do you have a tool to measure chainline like the one that Park sells or used to sell (http://www.parktool.com/repair/readhowto.asp?id=110)? You clamp it on the chainring and see where it lines up with your cassette. Then you know how far off your current setup is, and buy a new BB accordingly. As you said, 103mm is the shortest commonly available Shimano -compatible square taper BB. You an order a custom Phil Wood BB in shorter spindle lengths. However, it might be cheaper to just get a different crankset. Or use the middle and inner ring positions instead of the outer and middle.
 

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I just put a newer RaceFace crank that I had on the MTB onto the cross bike I'm building up. Chainline is not bad right off, just have to work with it a little bit but I think it will work. Yours with the square taper (mine is the new integrated style) should work fine if you just figure out the spindle length as described above.
 

· A wheelist
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Discussion Starter · #4 ·
trin2du said:
I just put a newer RaceFace crank that I had on the MTB onto the cross bike I'm building up. Chainline is not bad right off, just have to work with it a little bit but I think it will work. Yours with the square taper (mine is the new integrated style) should work fine if you just figure out the spindle length as described above.
My chainline is really bad and not usable. It's 50mm and it should be 40 - 41mm. The only shorter spindle is a 103 and that's 4mm shorter than my 107. But that's 4mm taken from both sides of the spindle (2mm each side) - a long way from the ideal of the 10mm I need taking from the drive side.

An hour ago I ordered a new compact road crankset and BB unit.
 

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If you haven't tried it already, and your BB is not a sealed unit you may be able to just reverse the spindle right and left sides to bring your chainline in. A hack solution but common with converting fixed gears on the cheap-
 

· A wheelist
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Discussion Starter · #7 ·
dyg2001 said:
I don't know if that particular crankset can be made to work or not on your frame. Do you have a tool to measure chainline like the one that Park sells or used to sell (http://www.parktool.com/repair/readhowto.asp?id=110)? You clamp it on the chainring and see where it lines up with your cassette. Then you know how far off your current setup is, and buy a new BB accordingly. As you said, 103mm is the shortest commonly available Shimano -compatible square taper BB. You an order a custom Phil Wood BB in shorter spindle lengths. However, it might be cheaper to just get a different crankset. Or use the middle and inner ring positions instead of the outer and middle.
Yep I have the ability to measure chainline. I used to have it written up on my website but it's not there anymore. The shortest stock BB spindle (103) won't be short enough. It's only 2mm less on the drive side and I need about 10.
 

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Discussion Starter · #8 ·
trin2du said:
That sucks. I'm still working with mine. Not too far off, just a bit of stress on the chain in the largest cogs. What crank did you end up going with?
The deflection of the chain in the biggest cogs is immense and not acceptable. I rode the bike yesterday but on a route with low hills so I didn't need my lowest gears. When I did go towards the lowest gears I could hear the complaints from the DT.

I'm going with a Shimano R600 compact and required BB cups & bearings from Bikeman. Owner Davis was a big help yesterday.
 

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Discussion Starter · #9 ·
ZenNMotion said:
If you haven't tried it already, and your BB is not a sealed unit you may be able to just reverse the spindle right and left sides to bring your chainline in. A hack solution but common with converting fixed gears on the cheap-
The BB unit that I wanted to use on the bike and with the RaceFace crankset was a beautiful old Syncros Ti unit that's fully adjustable (both cups). But with it correctly in place the non-drive crank was way too far from the chainstay and if I reversed it, it would be even further out. I could try it for a giggle though. It would show me how much less of a spindle I would need if I took measurements first.
 
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