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Old 12-28-06, 04:42 PM   #1
bobchmara
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Crank/BB recommendation for Nexus 8

I've spent a couple of hours searching the forums for crank/bb combos that provide a straight chainline for a bike with a Nexus 8 hub. The Harris site gives the crank info for the San Jos8, as does a thread here about a nice Schwinn World Voyageur (http://bikeforums.net/showthread.php...xus+8+schwinn). However, neither one states the bottom bracket info.

I know I can change the chainline by flipping the cog, and I've read that a straight chainline is essential for a Nexus 8. So what crank/bb combos are people are using with their Nexus 8's? A chain recommendation would be appreciated too.

Thanks,
Bob Chmara
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Old 12-28-06, 09:31 PM   #2
reverborama
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This was something that I spent a lot of time thinking about because there's really no way to know without having done it before -- or having a bunch of parts laying around to try out. I used a 172.5mm Sugino RD crank (CK1018) on mine. For a BB, I went with a Shimano BB-UN52 68/110 which was the size recommended by the guys at Harris for that crank. I'd defer to whatever they suggest with the crank you plan to use. I got the crank from Harris and the BB from an LBS (they installed it for me).
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Old 12-29-06, 04:11 AM   #3
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Quote:
Originally Posted by bobchmara
I've spent a couple of hours searching the forums for crank/bb combos that provide a straight chainline for a bike with a Nexus 8 hub. The Harris site gives the crank info for the San Jos8, as does a thread here about a nice Schwinn World Voyageur (http://bikeforums.net/showthread.php...xus+8+schwinn). However, neither one states the bottom bracket info.

I know I can change the chainline by flipping the cog, and I've read that a straight chainline is essential for a Nexus 8. So what crank/bb combos are people are using with their Nexus 8's? A chain recommendation would be appreciated too.

Thanks,
Bob Chmara
As light and strong as Octalink BB's are, I would go with a square taper. There are only a few sizes availabe in Octalink. The square taper must have 20 different lengths. Please don't quote me on that. What I'm trying to say is, you stand a better chance of getting the chain line correct with the larger selection of square taper BB's. JIS BB taper went from 103 to 122mm, with a lot of sizes inbetween. Good luck and let us know how it comes out.

Tim
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Old 12-29-06, 08:29 AM   #4
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Your chainline target is 43 or 48mm (http://bike.shimano.com/catalog/cycl...=1167402179521)

When built up in it's Nexus configuration, my 1x1 has a BulletProof crank on a Shimano 113mm bottom bracket with a $10 BMX chain. I'm using the ring on the outboard of the crank. Going by the Bulletproof spec, a 107 mm BB would have given me a perfect chainline but the stay of the 1x1 are to wide.

As for the straight chainline comment, my is supposedly off by ~0.100 and I've had zero issues (fyi, my Nexus is the coaster version).
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