Threadless BB Cartridges: Why/Why Not?

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...
--
PeteCresswell

(PeteCresswell) wrote:
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...

systems like that have been tried (merlin, klein, pinnarello), the
trick would be to settle on a standard.

it will also be denounced by the lugs and espressos crowd as a cost
cutting scheme.

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...

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.

Jobst Brandt

here's pinarello's version:

http://www.pinarello.com/eng/product...ology_gear.php

-Amit

wrote:
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...

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.

Jobst Brandt

Mavic did a very successful one for many years.. it's disappearance is
probably the most unfortunate by-product of the take over.. NOS ones
turn up from time to time but I wish someone would buy or steal the
design and make new ones.

Amit Ghosh writes:

here's Pirandello's version:

http://www.pinarello.com/eng/product...ology_gear.php

Unfortunately the mechanism remains secret. What holds the spindle
radially or laterally and how is the spindle attached to the bearing.
Without a press fit, this will become a creaking rouge generating
interface as will the bearings inside the BB shell. As I mentioned in
another thread, what are these folks thinking when they build their
web sites. Their 3-D image is a useless fuzzy picture unlike a cross
section line drawing.

Jobst Brandt

wrote in message
oups.com...
Mavic did a very successful one for many years.. it's disappearance is
probably the most unfortunate by-product of the take over.. NOS ones
turn up from time to time but I wish someone would buy or steal the
design and make new ones.

Nearly certain that the "Mavic" is still made, and marketed by Stronglight
these days.

Gary Jacobson
Rosendale, NY

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

Andrew Muzi 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...

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.

I don't recall, and don't call me Shirley.

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.

Picture reference please. I don't have much hope though because these
folks seldom show a cross section drawing where the function is
revealed. You might suspect they don't trust their patent protection.

Jobst Brandt

aka Jobst Brandt but not Shirley wrote:
Andrew Muzi 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...

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.

I don't recall, and don't call me Shirley.

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.

Picture reference please. I don't have much hope though because these
folks seldom show a cross section drawing where the function is
revealed. You might suspect they don't trust their patent protection.

Is this the referenced BB? See
http://www.bikepro.com/products/bottom_brackets/mavic.html.

--
Tom Sherman