72mm Bottom Bracket Shell / Alfine Crankset
08-06-12, 10:19 PM
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72mm Bottom Bracket Shell / Alfine Crankset
Hey guys,
Sorry for the noob question but I am in the process of putting together my first bike and I'm learning about all the different specs for each component. I bought a chinese CF frame on eBay that lists the bottom bracket shell width at 72mm with an English thread. I am going to be using an Alfine 8-Speed IGH in the rear and I was hoping to buy the matching crankset. However, the Alfine crankset has a listed BB width of 68mm.
My gut instinct is that this will not be long enough for my frame. Am I correct or am I misunderstanding something about Bottom Bracket specs? If this won't work, what cranksets do you guys recommend?
Thanks!
Sorry for the noob question but I am in the process of putting together my first bike and I'm learning about all the different specs for each component. I bought a chinese CF frame on eBay that lists the bottom bracket shell width at 72mm with an English thread. I am going to be using an Alfine 8-Speed IGH in the rear and I was hoping to buy the matching crankset. However, the Alfine crankset has a listed BB width of 68mm.
My gut instinct is that this will not be long enough for my frame. Am I correct or am I misunderstanding something about Bottom Bracket specs? If this won't work, what cranksets do you guys recommend?
Thanks!
08-07-12, 02:47 AM
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There are a few issues you have here.
The Afline crank comes in 2 versions, the S400 (Octalink https://techdocs.shimano.com/media/te...9830616019.pdf) and S500 (HT2 https://techdocs.shimano.com/media/te...9830604038.pdf), if using the S400, this specs a 68mm shell, but you could use a 73mm shell with the same axle length, if using the S500, the Spindle is a fixed length set for 68mm shells, and you can not increase this.
You may want to recheck the size the BB shell on the bike, 72mm is not a current standard, only 68mm & 73mm English thread and 70mm Italian thread are (not counting new press fits & standards like BB30, BB386 etc) would suggest the measurement is incorrectly, or the frame is defective in having a non-standard fitting.
The Afline crank comes in 2 versions, the S400 (Octalink https://techdocs.shimano.com/media/te...9830616019.pdf) and S500 (HT2 https://techdocs.shimano.com/media/te...9830604038.pdf), if using the S400, this specs a 68mm shell, but you could use a 73mm shell with the same axle length, if using the S500, the Spindle is a fixed length set for 68mm shells, and you can not increase this.
You may want to recheck the size the BB shell on the bike, 72mm is not a current standard, only 68mm & 73mm English thread and 70mm Italian thread are (not counting new press fits & standards like BB30, BB386 etc) would suggest the measurement is incorrectly, or the frame is defective in having a non-standard fitting.
08-07-12, 07:18 AM
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That 72 mm number is probably (hopefully) a typo. jimc101 is correct that English threaded bottom bracket shells come in 68 mm (road) and 73 mm (MTB) widths.
08-07-12, 10:23 AM
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There are a few issues you have here.
The Afline crank comes in 2 versions, the S400 (Octalink https://techdocs.shimano.com/media/te...9830616019.pdf) and S500 (HT2 https://techdocs.shimano.com/media/te...9830604038.pdf), if using the S400, this specs a 68mm shell, but you could use a 73mm shell with the same axle length, if using the S500, the Spindle is a fixed length set for 68mm shells, and you can not increase this.
You may want to recheck the size the BB shell on the bike, 72mm is not a current standard, only 68mm & 73mm English thread and 70mm Italian thread are (not counting new press fits & standards like BB30, BB386 etc) would suggest the measurement is incorrectly, or the frame is defective in having a non-standard fitting.
The Afline crank comes in 2 versions, the S400 (Octalink https://techdocs.shimano.com/media/te...9830616019.pdf) and S500 (HT2 https://techdocs.shimano.com/media/te...9830604038.pdf), if using the S400, this specs a 68mm shell, but you could use a 73mm shell with the same axle length, if using the S500, the Spindle is a fixed length set for 68mm shells, and you can not increase this.
You may want to recheck the size the BB shell on the bike, 72mm is not a current standard, only 68mm & 73mm English thread and 70mm Italian thread are (not counting new press fits & standards like BB30, BB386 etc) would suggest the measurement is incorrectly, or the frame is defective in having a non-standard fitting.
I messaged the seller and they said that the S500 crankset would fit but I guess I'm skeptical after hearing what you guys have to say. The specified that I wanted an English BSA Bottom Bracket which should have a 68mm standard width. I guess we'll see what the seller says. Thanks guys! Fingers crossed...
08-07-12, 10:50 AM
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This is the frame that I purchased.
I messaged the seller and they said that the S500 crankset would fit but I guess I'm skeptical after hearing what you guys have to say. The specified that I wanted an English BSA Bottom Bracket which should have a 68mm standard width. I guess we'll see what the seller says. Thanks guys! Fingers crossed...
I messaged the seller and they said that the S500 crankset would fit but I guess I'm skeptical after hearing what you guys have to say. The specified that I wanted an English BSA Bottom Bracket which should have a 68mm standard width. I guess we'll see what the seller says. Thanks guys! Fingers crossed...
08-07-12, 11:46 AM
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This is the frame that I purchased.
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08-07-12, 11:56 AM
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There are a number of issues with CF frames. There are a number
of issues with foreign E-bay sellers. There are a number of issues with
collecting the right parts and assembling a bicycle that comes to you
as a bare frame.
You have chosen to combine all three groups. Good luck
of issues with foreign E-bay sellers. There are a number of issues with
collecting the right parts and assembling a bicycle that comes to you
as a bare frame.
You have chosen to combine all three groups. Good luck
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08-07-12, 12:10 PM
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There are a number of issues with CF frames. There are a number
of issues with foreign E-bay sellers. There are a number of issues with
collecting the right parts and assembling a bicycle that comes to you
as a bare frame.
You have chosen to combine all three groups. Good luck
of issues with foreign E-bay sellers. There are a number of issues with
collecting the right parts and assembling a bicycle that comes to you
as a bare frame.
You have chosen to combine all three groups. Good luck
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