Newbie BB question
#1
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Joined: Dec 2005
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Newbie BB question
So I'm building my first fixed gear. I got a decent frame off of craigs list and am now looking at collecting all the components. I had saved up some money for this so I'm going fairly high end, but won't be able to build another bike for a long, long time.
I've decided on a sugino 75 crank, but am not sure what bottom bracket spindle length I should go for?
I read somewhere that the 75 took a 109mm spacing? My rear dropouts have 126mm spacing so I'm unsure how that will affect the chainline or the bb length.
I'm thinking about a PhilWood BB for duribility and adjustability(I usually spend more than I should up front but expect it to last forever) The BB shell is Italian threaded and measures 70mm wide. The phils that come in the vincinity of the 109 figure are 108, 110.5, and 111. Which one?
Definatly going with a Phil Rear Hub, probably 18t cog and 19t freewheel, 46t up front. (I have a few small to medium hills in my daily 8 or so mile path)
Any help would be much appreciated, thanks.
I've decided on a sugino 75 crank, but am not sure what bottom bracket spindle length I should go for?
I read somewhere that the 75 took a 109mm spacing? My rear dropouts have 126mm spacing so I'm unsure how that will affect the chainline or the bb length.
I'm thinking about a PhilWood BB for duribility and adjustability(I usually spend more than I should up front but expect it to last forever) The BB shell is Italian threaded and measures 70mm wide. The phils that come in the vincinity of the 109 figure are 108, 110.5, and 111. Which one?
Definatly going with a Phil Rear Hub, probably 18t cog and 19t freewheel, 46t up front. (I have a few small to medium hills in my daily 8 or so mile path)
Any help would be much appreciated, thanks.
#2
if you haven't found it yet, this site is gonna be your best friend https://sheldonbrown.com/fixed-conversion.html
chainline specific stuff is here https://sheldonbrown.com/gloss_ch.html#chainline (which is basically a fancy way of saying that i don't know the answer to your question).
chainline specific stuff is here https://sheldonbrown.com/gloss_ch.html#chainline (which is basically a fancy way of saying that i don't know the answer to your question).
#3
I have a 126mm spaced frame hooked to a phil rear flip/flop hub....I got a 110mm bottom bracket for it, and that works for me with stronglight double (my ring is on the inside) cranks that I have
unless someone can give you a first hand experience with sugino 75 cranks, I would say that the best thing would be to see if you can install an old bottom bracket, measure from center to the chainring, and then work from there (subtract what you need to ) to meet length of the center of hub to cog teeth on a phil hub (bout 42-43mm....see https://www.sheldonbrown.com/chainline.html )
don't know if that made sense.. I was able to install an old BB and measure and guestimate, and the 110 worked for me
unless someone can give you a first hand experience with sugino 75 cranks, I would say that the best thing would be to see if you can install an old bottom bracket, measure from center to the chainring, and then work from there (subtract what you need to ) to meet length of the center of hub to cog teeth on a phil hub (bout 42-43mm....see https://www.sheldonbrown.com/chainline.html )
don't know if that made sense.. I was able to install an old BB and measure and guestimate, and the 110 worked for me
#4
Sugino 75's take a JIS 109mm spindle (yes i know this is going to start a flamewar about sugino spindle compatibility) which should give you your 42mm chainline
126mm spacing doesn't affect your chainline, provided you respace a 120mm hub evenly (3mm on either side).
get the Phil 108mm BB (BRS08) and the italian cups. the way a phil BB mounts lets you adjust the chainline about 5mm in either direction, so getting the absolutely correct spindle length isn't crucial. (Don't get the 110.5 it has the wrong spindle taper)
126mm spacing doesn't affect your chainline, provided you respace a 120mm hub evenly (3mm on either side).
get the Phil 108mm BB (BRS08) and the italian cups. the way a phil BB mounts lets you adjust the chainline about 5mm in either direction, so getting the absolutely correct spindle length isn't crucial. (Don't get the 110.5 it has the wrong spindle taper)
#5
Originally Posted by baxtefer
126mm spacing doesn't affect your chainline, provided you respace a 120mm hub evenly (3mm on either side).
#7
hahaha..and...I don't know
maybe he could look up the 120 spaced hub (as opposed to the 130mm or whatever else they make) to be 36.75mm from center to shoulder and figure out what measurement he needed for the front
maybe he could look up the 120 spaced hub (as opposed to the 130mm or whatever else they make) to be 36.75mm from center to shoulder and figure out what measurement he needed for the front
#10
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Joined: Dec 2005
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Thanks for the suggestions. One of the big reasons I was going to go with the phils was the mentioned 5mm give. Figured if so long as I didn't go way too short it wouldn't matter a hell of a lot cause I could always adjust it one way or the other. I don't know anything about the taper debate. Over whether sugino will work with ISO or not? I think the 108 should be a safe bet. Thanks again.
#12
just to be somewhat clear, the debate in that thread isn't about whether or not you should use JIS or ISO tapers -- it was as to whether or not the Sugino and Shimano tapers, both of which are JIS, are different. JIS cranks should certainly not be used with ISO taper bottom brackets and vice versa. the differences in the tapers are significant enough that, while one may work a bit, you are at risk of rounding out your crank taper holes and/or slippage.
#13
yes, true. i think that some people are still convinced (wrongly) that sugino is ISO. i still don't get how they could both be JIS and be measurably different. anyway, there's a link in that thread (post #43) to another thread in which someone asserts sugino is compatible to ISO. go figure.
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#14
^ the link linked to old posts by sydney (RIP) who insisted that sugino was ISO.
I'm pretty sure he's partially correct in that the old-school sugino cranks were campy inspired/imitations and were thus ISO tapered.
the modern stuff is JIS.
I'm pretty sure he's partially correct in that the old-school sugino cranks were campy inspired/imitations and were thus ISO tapered.
the modern stuff is JIS.
#15
Originally Posted by habitus
yes, true. i think that some people are still convinced (wrongly) that sugino is ISO. i still don't get how they could both be JIS and be measurably different.
#16
Originally Posted by shants
i think that the most likely answer offered is that the sugino cranks are manufactured to tighter tolerances than many JIS bottom brackets, especially the cheaper shimano ones (un53, 73).
#17
Here's a good reference from John: https://www.businesscycles.com/tr-refspec.htm#b/b
#20
Originally Posted by baxtefer
^ please do.
oh, and while you're at it can you solve the equivalent Suntour Superbe debate too. It's pretty much the same problem.
Thanks.
oh, and while you're at it can you solve the equivalent Suntour Superbe debate too. It's pretty much the same problem.
Thanks.
#25
Originally Posted by baxtefer
^ the link linked to old posts by sydney (RIP) who insisted that sugino was ISO.
I'm pretty sure he's partially correct in that the old-school sugino cranks were campy inspired/imitations and were thus ISO tapered.
the modern stuff is JIS.
I'm pretty sure he's partially correct in that the old-school sugino cranks were campy inspired/imitations and were thus ISO tapered.
the modern stuff is JIS.
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