Shimano BB mystery vs. Campagnolo BB logic!?

leonidnk-<< Please, explain me who is wrong? Shimano or Campagnolo? I am going
to
replace my double Shimano 105 BB and crankset to triple Ultegra or Centaur.

Quoted message said:

Quoted message said:

<BR><BR>

Neither are wrong, Just Campagnolo gives you more options and seems more
logically thought out when it comes to front der placement, chainline and front
der action.

I would go with the Campagnolo as 118.5mm Octalink is going away. In 2005, the
ONLY BB available for these shimano triple cranks will be 105 level and that
will be gone in 2006, if shimano continues with their one piece gig for cranks.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

Leon said:

There are two axle length (spindle length) for Shimano Ultegra BB
(BB-6500) - 109,5 mm and 118,5 mm and two axle length (spindle length) for
Campagnolo Centaur BB (AC-H) – 111,0 mm and 115,5 mm.

In the Shimano Service Instruction Book: 118,5 mm is for triple front
chainwheel (triple crankset), 109,5 mm is for double front chainwheel
(double crankset). There is nothing about Seat Tube Diameter. I think that
is mystery. Bigger Seat Tube Diameter moves front derailleur more
laterally (outside). Front derailleur may come across with Seat Tube on
way to shift to smallest chainring and get stop.

In the Campagnolo Service Instruction Book everything are logical. They
recommend axle length (spindle length) depend of triple-double crankset
and Seat Tube Diameter. For instance: 111 mm is OK for triple and Seat
Tube Diameter 28,6 mm, but not OK for 35 mm tube, for 35 mm 115,5 mm is OK.

Please, explain me who is wrong? Shimano or Campagnolo? I am going to
replace my double Shimano 105 BB and crankset to triple Ultegra or Centaur.

I say that Shimano is right in this. What matters should not be the
derailleur capability -- that should be adequate for all seat tube
diameters -- but the chainline. The middle of the crankset should be
parallel to the middle of the cassette; that's why there is a difference
between double and triple.

I'm sure the Campy front derailleurs can handle whatever seat tube
diameter your bike has.

--

David L. Johnson

__o | A foolish consistency is the hobgoblin of little minds, adored by
_`\(,_ | little statesmen and philosophers and divines. --Ralph Waldo
(_)/ (_) | Emerson

David L. Johnson said:

Leon said:

There are two axle length (spindle length) for Shimano Ultegra BB
(BB-6500) - 109,5 mm and 118,5 mm and two axle length (spindle length)
for
Campagnolo Centaur BB (AC-H) – 111,0 mm and 115,5 mm.

In the Shimano Service Instruction Book: 118,5 mm is for triple front
chainwheel (triple crankset), 109,5 mm is for double front chainwheel
(double crankset). There is nothing about Seat Tube Diameter. I think
that
is mystery. Bigger Seat Tube Diameter moves front derailleur more
laterally (outside). Front derailleur may come across with Seat Tube on
way to shift to smallest chainring and get stop.

In the Campagnolo Service Instruction Book everything are logical. They
recommend axle length (spindle length) depend of triple-double crankset
and Seat Tube Diameter. For instance: 111 mm is OK for triple and Seat
Tube Diameter 28,6 mm, but not OK for 35 mm tube, for 35 mm 115,5 mm is
OK.

Please, explain me who is wrong? Shimano or Campagnolo? I am going to
replace my double Shimano 105 BB and crankset to triple Ultegra or
Centaur.

I say that Shimano is right in this. What matters should not be the
derailleur capability -- that should be adequate for all seat tube
diameters -- but the chainline. The middle of the crankset should be
parallel to the middle of the cassette; that's why there is a difference
between double and triple.

I'm sure the Campy front derailleurs can handle whatever seat tube
diameter your bike has.

You did not get my point, David. If you use just one axle length and same
crankset, you get always same chainline. You are right. But with a
different Seat Tube Diameters you should get a different front derailleur
positions. And with a big Seat Tube Diameter and a short axle length,
front derailleur does not have room to shift to the smallest chainring. I
hope that is clear now.

Leon said:

You did not get my point, David. If you use just one axle length and same
crankset, you get always same chainline. You are right. But with a
different Seat Tube Diameters you should get a different front derailleur

That was clear before, but chainline is more important than derailer
position. Derailers have adjustments; chainline doesn't.

Quoted message said:

positions. And with a big Seat Tube Diameter and a short axle length,
front derailleur does not have room to shift to the smallest chainring. I
hope that is clear now.

If it's that bad, then only having two BB lengths won't help. The
longer BB will work for the double, but nothing will work for the
triple. A third, longer BB would be necessary.
--
Rick Onanian

Rick Onanian said:

Leon said:

You did not get my point, David. If you use just one axle length and
same
crankset, you get always same chainline. You are right. But with a
different Seat Tube Diameters you should get a different front
derailleur

That was clear before, but chainline is more important than derailer
position. Derailers have adjustments; chainline doesn't.

Quoted message said:

positions. And with a big Seat Tube Diameter and a short axle length,
front derailleur does not have room to shift to the smallest chainring.
I
hope that is clear now.

If it's that bad, then only having two BB lengths won't help. The
longer BB will work for the double, but nothing will work for the
triple. A third, longer BB would be necessary.
--
Rick Onanian

That is case with Compagnolo BB (AC-H):
• CENTAUR - AC-H - AC-S - SC-S bottom brackets:
- axle length: 111 mm (symmetrical)
- for double crankset: CENTAUR 10s - CENTAUR 9s - VELOCE 9s - MIRAGE 9s -
XENON 9s
- for tubes: ø 28.6 mm - ø 32 mm - ø 35 mm
- chain line: 43.5 mm
- for triple crankset: CENTAUR 9s - VELOCE 9s - MIRAGE 9s - XENON 9s
- for tubes: ø 28.6 mm
- chain line: 45 mm
• AC-H - SC-S bottom brackets:
- axle length: 115.5 mm
- for triple crankset: CENTAUR 9s - VELOCE 9s - MIRAGE 9s - XENON 9s
- for tubes: ø 32 mm - ø 35 mm
- chain line: 47.5 mm

How I said in the beginning: Campagnolo BB is recommendations is logical.

Leon said:

Rick Onanian said:

If it's that bad, then only having two BB lengths won't help. The
longer BB will work for the double, but nothing will work for the
triple. A third, longer BB would be necessary.

Quoted message said:

That is case with Compagnolo BB (AC-H):
- axle length: 111 mm (symmetrical)
- axle length: 115.5 mm

Your list only included two axle lengths. For the range of seat tube
diameters about which you're concerned, three axle lengths are
necessary, and yet the result ignores chainline.

Maybe Campagnolo's front derailers don't offer sufficient adjustment
for fat seat tubes...or maybe Shimano just doesn't offer a setup
that will work for fat seat tubes with triple cranks -- although
Ultegra derailer, triple crank, and 118.5mm BB work fine on my Giant
TCR2 with it's fat aluminum tubes.

Quoted message said:

How I said in the beginning: Campagnolo BB is recommendations is logical.

I can't see the logic in sacrificing chainline for the ability to
use fat tubes with narrow-range derailers.
--
Rick Onanian

Rick Onanian said:

Leon said:

On Tue, 25 May 2004 11:50:42 -0400, Rick Onanian <[email hidden]>

Quoted message said:

If it's that bad, then only having two BB lengths won't help. The
longer BB will work for the double, but nothing will work for the
triple. A third, longer BB would be necessary.

Quoted message said:

That is case with Compagnolo BB (AC-H):
- axle length: 111 mm (symmetrical)
- axle length: 115.5 mm

Your list only included two axle lengths. For the range of seat tube
diameters about which you're concerned, three axle lengths are
necessary, and yet the result ignores chainline.

Maybe Campagnolo's front derailers don't offer sufficient adjustment
for fat seat tubes...or maybe Shimano just doesn't offer a setup
that will work for fat seat tubes with triple cranks -- although
Ultegra derailer, triple crank, and 118.5mm BB work fine on my Giant
TCR2 with it's fat aluminum tubes.

Quoted message said:

How I said in the beginning: Campagnolo BB is recommendations is
logical.

I can't see the logic in sacrificing chainline for the ability to
use fat tubes with narrow-range derailers.
--
Rick Onanian

Very interesting, Rick! I have Giant TCR2 (2002 edition) with Shimano 105
group (triple). I can not shift to the smallest chainring, 35 mm seat tube
is on the way. There is only about 1 mm room is lacking. May be my bike
was assembled with 109,9 mm axle? I do not know how I may check axle
length.

This seems to be getting awfully complicated...
First, to measure the length of your BB axle, simply remove both cranks and
measure its length from end to end. I use a 6" dial caliper which avoids
dealing measuring with the diameter of the BB shell in the way. If the shell
is in your way, then disassemble the axel from the BB and measure.

Is it possible that Shimano accounts for the seat tube diameter variations
in the different sizes they sell? On their MTB front derailleurs, they all
seem to work fine with the standard long BB for triples if you buy one with
the proper diameter clamp.

At the risk of stirring the pot still further, do Shimano's road front
derailleurs also incorporate the further complications of all the
complications involved with the combinations of top/bottom pull, and
top/bottom swing?

B maytum
[email hidden]

"Leon" <[email hidden]> wrote in message news:opr8kg6fgd0lcd5c@dell8200...

Quoted message said:

Rick Onanian said:

Leon said:

On Tue, 25 May 2004 11:50:42 -0400, Rick Onanian <[email hidden]>
wrote:
> If it's that bad, then only having two BB lengths won't help. The
> longer BB will work for the double, but nothing will work for the
> triple. A third, longer BB would be necessary.

Quoted message said:

That is case with Compagnolo BB (AC-H):
- axle length: 111 mm (symmetrical)
- axle length: 115.5 mm

Your list only included two axle lengths. For the range of seat tube
diameters about which you're concerned, three axle lengths are
necessary, and yet the result ignores chainline.

Maybe Campagnolo's front derailers don't offer sufficient adjustment
for fat seat tubes...or maybe Shimano just doesn't offer a setup
that will work for fat seat tubes with triple cranks -- although
Ultegra derailer, triple crank, and 118.5mm BB work fine on my Giant
TCR2 with it's fat aluminum tubes.

Quoted message said:

How I said in the beginning: Campagnolo BB is recommendations is
logical.

I can't see the logic in sacrificing chainline for the ability to
use fat tubes with narrow-range derailers.
--
Rick Onanian

Very interesting, Rick! I have Giant TCR2 (2002 edition) with Shimano 105
group (triple). I can not shift to the smallest chainring, 35 mm seat tube
is on the way. There is only about 1 mm room is lacking. May be my bike
was assembled with 109,9 mm axle? I do not know how I may check axle
length.

Leon said:

Very interesting, Rick! I have Giant TCR2 (2002 edition) with Shimano 105
group (triple). I can not shift to the smallest chainring, 35 mm seat tube
is on the way. There is only about 1 mm room is lacking. May be my bike
was assembled with 109,9 mm axle? I do not know how I may check axle
length.

Are you saying that the front derailer cage hits the seat tube
before it goes far enough to shift?

Check the BB. It's often printed right on visible parts of the BB.

Either way, where did you buy the bike that allowed it out their
door like that?
--
Rick Onanian

Leon said:

You did not get my point, David. If you use just one axle length and same
crankset, you get always same chainline. You are right. But with a
different Seat Tube Diameters you should get a different front derailleur
positions. And with a big Seat Tube Diameter and a short axle length,
front derailleur does not have room to shift to the smallest chainring. I
hope that is clear now.

I did get your point. I said, twice, that a good derailleur would have
enough clearance for any (well, any reasonable) seat tube diameter. You
are talking about a 4mm difference in radius between the largest and
smallest tubes in common use. The derailleur should be able to accomodate
that.

Conversely, you should not have to mess up the chainline in order to
obtain derailleur clearance.

--

David L. Johnson

__o | Arguing with an engineer is like mud wrestling with a pig... You
_`\(,_ | soon find out the pig likes it!
(_)/ (_) |

Rick Onanian said:

Maybe Campagnolo's front derailers don't offer sufficient adjustment
for fat seat tubes...

No. They do. Campy is just being fussy here, as far as I can determine.
They are known for being very conservative in their specs. Probably so
they can blame the user no matter what goes wrong.

I strongly emphasize that chainline should be the first consideration.

--

David L. Johnson

__o | Do not worry about your difficulties in mathematics, I can assure
_`\(,_ | you that mine are all greater. -- A. Einstein
(_)/ (_) |

Rick Onanian said:

Leon said:

Very interesting, Rick! I have Giant TCR2 (2002 edition) with Shimano
105
group (triple). I can not shift to the smallest chainring, 35 mm seat
tube
is on the way. There is only about 1 mm room is lacking. May be my bike
was assembled with 109,9 mm axle? I do not know how I may check axle
length.

Are you saying that the front derailer cage hits the seat tube
before it goes far enough to shift?

Check the BB. It's often printed right on visible parts of the BB.

Either way, where did you buy the bike that allowed it out their
door like that?
--
Rick Onanian

I buy the bike from eBay. Bike came with double front der. After my
complain to seller, I got a triple front der. That was November already. I
mount triple front der. now and found the problem. I have to check axle
length.

Rick Onanian said:

Leon said:

Very interesting, Rick! I have Giant TCR2 (2002 edition) with Shimano 105
group (triple). I can not shift to the smallest chainring, 35 mm seat tube
is on the way. There is only about 1 mm room is lacking. May be my bike
was assembled with 109,9 mm axle? I do not know how I may check axle
length.

Take the cranks off. Hold a ruler just below the bottom bracket. Note
length from end to end. That's it.

Quoted message said:

Are you saying that the front derailer cage hits the seat tube before it
goes far enough to shift?

Are you sure it's not just an adjustment problem?

--

David L. Johnson

__o | "What am I on? I'm on my bike, six hours a day, busting my ass.
_`\(,_ | What are you on?" --Lance Armstrong
(_)/ (_) |

David L. Johnson said:

Rick Onanian said:

Maybe Campagnolo's front derailers don't offer sufficient adjustment
for fat seat tubes...

No. They do. Campy is just being fussy here, as far as I can determine.
They are known for being very conservative in their specs. Probably so
they can blame the user no matter what goes wrong.

I strongly emphasize that chainline should be the first consideration.

By Shimano I should have 45 mm chainline;
By Campagnolo I should have 47 mm chainline;
How it is possible?

Now I have 45 mm chainline, but triple 105 front der. does not have enough
room for shifting to the smallest chainring.

David L. Johnson said:

Rick Onanian said:

Leon said:

Very interesting, Rick! I have Giant TCR2 (2002 edition) with Shimano
105
group (triple). I can not shift to the smallest chainring, 35 mm seat
tube
is on the way. There is only about 1 mm room is lacking. May be my bike
was assembled with 109,5 mm axle? I do not know how I may check axle
length.

Take the cranks off. Hold a ruler just below the bottom bracket. Note
length from end to end. That's it.

If I have 45 mm chainline, may I be sure about 118,5 mm axle length? Or I
need check axle length anyway?

Quoted message said:

Quoted message said:

Are you saying that the front derailer cage hits the seat tube before it
goes far enough to shift?

Are you sure it's not just an adjustment problem?

I am not able adjust front der. properly, I have to make a hole in seat
tube.

Quoted message said:

I have to make a hole in seat

tube

You jest!

Look at where your 105 front derailleur bottoms out against the seat tube. It
is probably not the cage but a rounded protrusion on the inside leg of the
parallelogram; this can easily be filed down. If you remove 1 mm in thickness
it will let the cage move about 2 mm farther to the inside.

Mike Yankee

(Address is munged to thwart spammers.
To reply, delete everything after "com".)

MikeYankee said:

Quoted message said:

I have to make a hole in seat

tube

You jest!

Look at where your 105 front derailleur bottoms out against the seat
tube. It
is probably not the cage but a rounded protrusion on the inside leg of
the
parallelogram; this can easily be filed down. If you remove 1 mm in
thickness
it will let the cage move about 2 mm farther to the inside.

Mike Yankee

(Address is munged to thwart spammers.
To reply, delete everything after "com".)

Thanks, I should try.

david-<< I say that Shimano is right in this. What matters should not be the
derailleur capability -- that should be adequate for all seat tube
diameters -- but the chainline. >><BR><BR>

Problem is that on some really fat seattubed frames, like Serotta Legend, you
can't get the shimano triple fder to move inward far enough to get the chain on
the small ring.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

leon-<< I am not able adjust front der. properly, I have to make a hole in seat

tube. >><BR><BR>

A round steel rod, a tap on the seatube, and the fder for shimano, will move
farther oin.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"