BB size

Steve W said:

When a dimension is quoted for a bottom bracket where is it measured?

Two dimensions to take note of, one the width of bottom bracket shell
in the frame, the other the axle length of the BB.

The shell measurement is simply the width of the shell from edge to
edge, typically 68 or 73mm.

The bottom bracket axle is again measured end to end. This dimension
is critical to getting correct chainline, and will vary depending on
frame design, crankset choice etc.

--

"Bob"

Email address is spam trapped.
To reply directly remove the beverage.

in message <[email hidden]>, Call me Bob

(') said:

Steve W said:

When a dimension is quoted for a bottom bracket where is it measured?

Two dimensions to take note of, one the width of bottom bracket shell
in the frame, the other the axle length of the BB.

The shell measurement is simply the width of the shell from edge to
edge, typically 68 or 73mm.

The bottom bracket axle is again measured end to end. This dimension
is critical to getting correct chainline, and will vary depending on
frame design, crankset choice etc.

Also, don't forget the thread issue. To keep things simple, stick to
'English' (now ISO) thread. But that means making sure your frame comes
with English thread...

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

I shall continue to be an impossible person so long as those
who are now possible remain possible -- Michael Bakunin

Simon Brooke said:

in message <[email hidden]>, Call me Bob

(') said:

Steve W said:

When a dimension is quoted for a bottom bracket where is it measured?

Two dimensions to take note of, one the width of bottom bracket shell
in the frame, the other the axle length of the BB.

The shell measurement is simply the width of the shell from edge to
edge, typically 68 or 73mm.

The bottom bracket axle is again measured end to end. This dimension
is critical to getting correct chainline, and will vary depending on
frame design, crankset choice etc.

Also, don't forget the thread issue. To keep things simple, stick to
'English' (now ISO) thread. But that means making sure your frame comes
with English thread...

If it's "Italian" (like my bike), then I think it usually has "36x24"
somewhere on the ends (not the shaft) and it will also be 70mm wide.

It may also come undone of its own accord, just like mine has twice
recently. Now assembled with threadlock...

--
Mike