Bicycle Mechanics - campagnolo triple bottom brackets

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View Full Version : campagnolo triple bottom brackets


p4nh4ndle
01-11-11, 07:26 PM
Anybody know if the current iteration of the centaur bottom bracket (recommended for triple cranksets by campagnolo) is symmetrical or asymmetrical?

I want to put a record triple 10spd crankset on my bike and have been having a devil of a time sourcing the appropriate 111mm bb.

thanks
Matt


HillRider
01-11-11, 07:58 PM
Square taper Centaur/Veloce/Mirage bb were symetrical and 111 mm for a double or a triple if limited to a 28.6 mm seat tube and 115.5 mm for the triple used on frames with 31.8 or 35 mm seat tubes.

Chorus/Record bottom brackets were asymetrical and 102 mm for a double and 111 mm for the triple for all seat tube diameters.

Edit: You didn't look hard enough. Licktons in Chicago has all of the square taper Campy bottom brackets including the Centaur 111mm. Look here:

http://www.lickbike.com/productpage.aspx?PART_NUM_SUB='0205-13'

ultraman6970
01-12-11, 07:03 AM
A simple question, why to use triple when u can use compact? My main concern with triple is that u have gears redundancy everywhere, many of the gears combinations are almost epeated 2 to 3 times. With compact you avoid crossing the chain big time also.

Good luck :)


HillRider
01-12-11, 07:11 AM
A simple question, why to use triple when u can use compact? My main concern with triple is that u have gears redundancy everywhere, many of the gears combinations are almost epeated 2 to 3 times. With compact you avoid crossing the chain big time also.

Good luck :)
I don't know where you live or what kind of terrine you ride in but a compact can never provide the same low gear as a triple. Despite their current fashion, a compact isn't the answer to everything.

p4nh4ndle
01-12-11, 08:50 AM
thanks Hill, for both your answers.
and thanks for the Lickton's site; indeed, I'd forgotten about that one.

DaveSSS
01-12-11, 09:34 AM
Gear redundancy is only an issue for those who don't understand how to shift a triple. When you get to the middle ring and next to largest cog and need a lower gear, all you do is shift to the little ring, then 2-3 cogs smaller, just like you do when shifting to the middle ring. There is absolutely nothing to keep track of. so the redundancy is much ado about nothing.

Less redundancy makes the shifting process more difficult. With a compact crank, you always shift one more cog after shifting between the chainrings (3-4 instead of 2-3) due to the reduced redundancy. In the worst case, you could make a 53/27 with no redundancy and then you'd have to shift through all 9 cogs after every chainring shift. Wouldn't that be fun?

Drew Eckhardt
01-12-11, 11:53 AM
A simple question, why to use triple when u can use compact?

The triple gets a combination of more range, closer spacing between gears in your cruising range, less shifting rings, and a better chainline.



My main concern with triple is that u have gears redundancy everywhere
That's good. You can put it in a ring and leave it there for less front shifting. When you need a double shift it can be a three cog change (a single right lever activation with Campagnolo) instead of five (two when moving to a bigger cog and smaller ring).

I made the mistake of switching a triple for a compact with the same range and wouldn't do it again.

In the 8 speed era I ran 50-40-30 x 13-14-15-16-17-18-19-21 in Boulder, CO so I had perfect gears for rides east (plains) or west (mountains) - like a low gear of 42x28 and straight block without changing freewheels. With that cassette discontinued I switched to 9 speeds with a 23 on the end, and swapped the front for a 50-34 after wearing out the chain rings because 34x23 is the same as 30x21 and everyone knows two rings are better than three.

Disregarding the extreme big/big and small/small combinations there's only one gear of overlap (50x21 and 34x14).

Any terrain/wind/fatigue combinations which involve speed fluctuating below 15 and above 17 miles an hour leads to a lot of double shifts with a five cog change each time.

With 50-40-30x13-14-15-16-17-18-19-21-23 the middle ring is good for comfortably cruising at 12-20 MPH when you avoid the biggest and smallest cogs.



, many of the gears combinations are almost epeated 2 to 3 times. With compact you avoid crossing the chain big time also.
My chainline is worse with the compact. If I want to go 16 MPH it's the second largest cog at 50x21 or second smallest at 34x14. On the triple I could run 40x16 or 40x17 in the middle of the cassette.

Drew Eckhardt
01-12-11, 11:58 AM
I don't know where you live or what kind of terrine you ride in but a compact can never provide the same low gear as a triple. Despite their current fashion, a compact isn't the answer to everything.

Unless you're a bike company. Once you convince people that compacts are an alternative to triples you can make and stock fewer crank, rear derailleur, front derailleur, shifter, and bike variants. That's good for the bottom line.

HillRider
01-12-11, 01:20 PM
Unless you're a bike company. Once you convince people that compacts are an alternative to triples you can make and stock fewer crank, rear derailleur, front derailleur, shifter, and bike variants. That's good for the bottom line.
All too true. SRAM seems to have taken this to the extreme and doesn't offer a road triple of any kind and is trying to get away from MTB triples.