Pete Cresswell writes:
Thanks to Werehatrack for introducing me to the concept...
Now it begs the question:
Why are BB shells threaded in the first place?
i.e. Why don't most bikes just come with threadless
already installed?
Sounds like there's a downside...

wrote:
I must have missed it but could you direct me to a web site where I
can see the cross section of a threadless BB? The only ones I know of
were on Ashtabula cranks and they had a larger diameter.

Surely, you recall the Mavic system of the eigties? Conical
rings on both sides screw onto a threaded Phil-ish
cartridge. IN Mavic's design, the frame gets milled with a
4mm chamfer on each end of the BB. The later
all-nylon-casing types (KSS brand) seem to work fine
without that chamfer.

They are both more expensive to make and much more time
consuming to install. As such they can't be an OEM part and
in today's world that is a kiss of death. Low volume means
high prices which leads to low volume and therefore high
prices, etc.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971