Bottom Bracket Tapers

I looked over on Sheldon's website but couldn't discover the difference in tapers of Shimano and Campy bottom brackets. It always bothered me that they weren't compatible (sort of like Duane and the truth).

Does anyone know what these tapers are?

https://propelsteps.files.wordpress....rs-3.jpg?w=585

On 12/22/2016 10:26 AM, wrote:
I looked over on Sheldon's website but couldn't discover the difference in tapers of Shimano and Campy bottom brackets. It always bothered me that they weren't compatible (sort of like Duane and the truth).

Does anyone know what these tapers are?


The original Stronglight of the 1930s and most quality
classic era cranks (including Campagnolo) used the same
taper until Shimano decided to use a different (smaller)
section of that taper. Hence our modern consternation
between big and small spindle ends. It's not the taper
angle, only the section.

http://www.yellowjersey.org/photosfr...t/3SPINDLE.JPG

The leftmost spindle shown is a different (obsolete) taper
angle for cast cranks.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

JIS (Japanese Industrial Standard) is used by Shimano and all Asian cranksets. ISO is used by Campagnolo and maybe that is all. As Andy mentioned, JIS is smaller so it goes too far onto a Campagnolo crank.

On Thursday, December 22, 2016 at 11:38:30 AM UTC-8, wrote:
JIS (Japanese Industrial Standard) is used by Shimano and all Asian cranksets. ISO is used by Campagnolo and maybe that is all. As Andy mentioned, JIS is smaller so it goes too far onto a Campagnolo crank.

Thanks guys.

By the way - I said that the Motobecane I bought had a Made In France sticker on it. That must have been another French bike I was looking at - a modern Peugeot. This one turns out to be a Motobecane USA and someone said that these are made in Japan. Well, if it's made in Japan they have improved quite a bit since Bridgestone was the best they could offer.

On 12/22/2016 1:25 PM, AMuzi wrote:
On 12/22/2016 10:26 AM, wrote:
I looked over on Sheldon's website but couldn't discover the
difference in tapers of Shimano and Campy bottom brackets. It always
bothered me that they weren't compatible (sort of like Duane and the
truth).

Does anyone know what these tapers are?


The original Stronglight of the 1930s and most quality classic era
cranks (including Campagnolo) used the same taper until Shimano decided
to use a different (smaller) section of that taper. Hence our modern
consternation between big and small spindle ends. It's not the taper
angle, only the section.

http://www.yellowjersey.org/photosfr...t/3SPINDLE.JPG

The leftmost spindle shown is a different (obsolete) taper angle for
cast cranks.

Do you know how the internal (i.e. female) square taper is cut into the
cranks?

(Am I still allowed to say "female"?)


--
- Frank Krygowski

On Thursday, December 22, 2016 at 11:38:30 AM UTC-8, wrote:
JIS (Japanese Industrial Standard) is used by Shimano and all Asian cranksets. ISO is used by Campagnolo and maybe that is all. As Andy mentioned, JIS is smaller so it goes too far onto a Campagnolo crank.

There was a period of time when Shimano used an ISO-ish taper. You could interchange old Dura Ace with Campagnolo. That's was way back when odd, non-interchangeable, proprietary parts were not considered a good thing -- unless you were French.

-- Jay Beattie.

On 12/22/2016 1:38 PM, wrote:
JIS (Japanese Industrial Standard) is used by Shimano and all Asian cranksets. ISO is used by Campagnolo and maybe that is all. As Andy mentioned, JIS is smaller so it goes too far onto a Campagnolo crank.


Not quite all Asian cranks. Classic taper section on Dura
Ace square taper & Sugino 75.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 12/22/2016 2:57 PM, Frank Krygowski wrote:
On 12/22/2016 1:25 PM, AMuzi wrote:
On 12/22/2016 10:26 AM, wrote:
I looked over on Sheldon's website but couldn't discover the
difference in tapers of Shimano and Campy bottom
brackets. It always
bothered me that they weren't compatible (sort of like
Duane and the
truth).

Does anyone know what these tapers are?


The original Stronglight of the 1930s and most quality
classic era
cranks (including Campagnolo) used the same taper until
Shimano decided
to use a different (smaller) section of that taper. Hence
our modern
consternation between big and small spindle ends. It's not
the taper
angle, only the section.

http://www.yellowjersey.org/photosfr...t/3SPINDLE.JPG

The leftmost spindle shown is a different (obsolete) taper
angle for
cast cranks.

Do you know how the internal (i.e. female) square taper is
cut into the cranks?

(Am I still allowed to say "female"?)



They used to be broached but the surfaces of premium cranks
have shown milling marks for a long time. Mid to low end
cranks are thixoformed.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Thursday, December 22, 2016 at 1:15:37 PM UTC-5, DATAKOLL MARINE RESEARCH wrote:
https://propelsteps.files.wordpress....rs-3.jpg?w=585

if the crank n tapir doahn fit tightly, soda can shims cut with scissors laid long on 2 opposing flats greased with red Loctite may hold the unit. Dangling long on he outboard side so as the wrenching on slides more shim inward nt running out of shim near end torque.

clean tapir flats with no rough edges male or female. filum edges.

clean threads nut n shaft lubed with red locktite.

Torque is TIGHT with a 6-8" handle. TIGHT. SQWEEK

let set 24-36 hours before using.