-
• #2
102 mm is the correct axle length for Chorus double cranks. I've got a bike with the same setup and just double checked. The inner ring is meant to be just a gnat's cock away from the chainstay, presumably to give a good chain line on as many gears as possible.
-
• #3
Nice one andy, that's what I needed to know, cheers mate.
-
• #4
Just been reading about
gnat cockserr BB lengths. Worth noting that, certainly for older GS/NR/SR stuff, with Italian cups you were meant to use a spindle one mm longer than the correct length for french or BSC cups...www.bicycleclassics.com/bottom.html
This of course may not apply to newfangled stuff like this... give me a cotter pin and a hammer any day.
-
• #5
gnat cocks? wtf the skully!
-
• #6
The first and second posts use this phrase. I was just trying to be 'down' with the big boys.
-
• #7
oh yeah! missed that! maybe i should go and research "gnat cocks!" and also be down with the kids xD
-
• #8
when i typed it into google it asked me if i meant giant cocks xD
-
• #9
Jeez kids today... it's an internationally recognised (SI) unit of length for crying out loud
-
• #10
Just been reading about
gnat cockserr BB lengths. Worth noting that, certainly for older GS/NR/SR stuff, with Italian cups you were meant to use a spindle one mm longer than the correct length for french or BSC cups...Does this mean my Sugino 103 mm bb will work with Record road doubles?
-
• #11
... in italian thread cups... in 70 mm shells, if your era of record requires 102 mm
Its a fucking minfield. I hate BBs.
-
• #12
... in italian thread cups... in 70 mm shells, if your era of record requires 102 mm
Its a fucking minfield. I hate BBs.
Me too. So if I have an English 68 mm bb shell, ideally I need a 102 mm bb for campy road cranks. Is 1/2 a mm extra on each side going to be problematic?
-
• #13
Does this mean my Sugino 103 mm bb will work with Record road doubles?
Isn't a Sugino bottom bracket JIS? Campag bbs are ISO so you might have a problem with the cranks going too close to the chainstays (crushing the poor gnat's cock in the process).
-
• #14
Here's the obligatory Sheldon link on the topic of BB tapers;
-
• #15
I have a fitted, but never used Chorus 102mm BB (British) - Fucking smooth - £20
-
• #16
I have a fitted, but never used Chorus 102mm BB (British) - Fucking smooth - £20
Shit, good timing - I'll send you a PM
-
• #17
K, so, sort of on topic. Just want someone smart to confirm that I am actually right.
I've got a set of Campag Chorus double ring road cranks (early 90s) coming my way. I plan to (for now) run one ring fixed. I believe the chainline with a 102mm BB is 43.5 to the middle of the two rings. Assuming the back is running 41ish (Suzue Sil + EAI cog = 41.47), this means the outer ring is going to be a bit too far out for riding fixed (measured some Shimano 600s, and it's about 3.5mm from the centre to either ring, so ~47mm).
Without having the cranks with me, anyone know the actual distance to the rings? I'm guessing a 102 spindle + chain ring on the inner will be around what I want (40mm, give or take)? And I don't plan to keep the Suzue in for ever, so if I happen to come across a decent hub that's going to give me a wider chainline, I should be aiming for 47mmish (which a Goldtec + EAI would be preatty close to)?
Cheers!
-
• #18
Mark, if you can wait until the weekend I'll measure my setup, which is running a standard double on a 102 mm bb, and let you know what the chainline is for both the inner and outer chainrings.
-
• #19
There's a BB on the forum right now, which is the only reason I'm being hasty. Not sure what length the BB is yet though. I'll probably just get it anyway if it's 102...
-
• #20
Is the frame Italian or English threaded? If the former I've a bb you can have.
-
• #21
Latter I'm afraid :( 'tis the Raleigh low-pro. Thanks though!
-
• #22
102 mm is the correct axle length for Chorus double cranks. I've got a bike with the same setup and just double checked. The inner ring is meant to be just a gnat's cock away from the chainstay, presumably to give a good chain line on as many gears as possible.
Andy, another quick question. Is a gnat's cock wider than a mil (anyone ever read Aristophanes' Clouds? These are the types of questions that can get you killed! [/nerd]).
Just sourced a 101mm Chorus BB for a decent price. Sounds like this could be an issue though. Could probably bodge it though (1mm spacer)...
-
• #23
From memory, it's probably more than a millimetre for the inner chainring. So it'll depend in part on how you mount your chainring (you dirty whore), i.e. if you go on the inside or outside of the spider. A 101 mm bb will presumably move the chain ring in 0.5 mm anyway which is, even by gnat's cock standards, miniscule.
I reckon it'll be fine. But I'm always optimistic on these things. :-)
-
• #24
oh yeah, half a mil. duh.
-
• #25
To Lazarus this thread- for an early nineties Chorus road double am I correct in thinking that a current campag square taper 102mm bottom bracket would be fine?
p.s. if anyone had such a bb going spare let me know.
English btw- I don't do foreign.
I've got a '95/'96 Campag Chorus double chainset that's going on a frame with a British BB 68mm shell and 130mm rear spacing.
According to the catalogues for those years the BB came in either 102, 111 or 115.5.
The cranks were previously on a frame with a 70/102 italian BB, but I'm not too inclined to assume this was correct (partly because the inner ring was only a gnat's cock away from the chainstay), or that it would work on a 68mm shell.
Oh and it's all square taper of course.
So do any of you actually know which would be the correct axle length?
Thanks