John B. Slocomb wrote:
On Mon, 2 Sep 2019 03:19:15 +0000 (UTC), Ralph Barone
wrote:

John B. Slocomb wrote:
On Sun, 1 Sep 2019 18:12:12 -0700 (PDT), Tom Kunich
wrote:

On Friday, August 30, 2019 at 7:49:45 PM UTC-7, AMuzi wrote:
On 8/30/2019 9:07 PM, Don Gillies wrote:
If a vintage crank needs an offset on one side, you can just add the
offset to the other side and substitute a symmetric crankset, so a 116
R+5 bottom bracket can be substituted with a 121 symmetric bottom
bracket (120 or 122 would work fine.)

- Don Gillies
Palo Alto, CA, USA


Which makes your tread ( aka "Q") wider.
Deal breaker for some riders.

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

The iliac width is why the BB50 has become so common. People's legs do
not have to spread so wide and the length of the BB shaft is narrower
and consequently stiffer. Average hip breadth is 13" or 33 cm. So the
narrower the BB the more angularly correct a pedal spacing would be.

Time for Frank to tell us all that I don't know what I'm talking about.

By gorry Tommie! You hit the nail right on the head!

You whip out these hip width measurements like they are carved on
tablets of stone... and perhaps they are. Except that you neglect to
mention that hip width in males is noticible different than in
females. To the extent thjat a female's knee joints are closer
together then her hip joints while a male's knee joints are generally
speaking the same width.

But perhaps you are telling us that women don't ride bicycles? Or the
moon is made of blue chease?

--

Cheers,

John B.


And, of course, the important measurement when discussing Q factor is how
far apart the ankles are when doing a similar exercise like walking or
running.

I wouldn't argue except to say that over the years I've owned quite a
number of bicycles which undoubtedly had varying BB width... and I've
never been able to tell the difference. I've never jumped on a bike
and thought "Gee, those pedals are a long ways apart" or conversely,
"Gee those pedals are really close together".

For that matter, I see people running and their stride seems wider
with running shoes on than when barefoot.

As always, I may be wrong, but like many of the things that seem to be
of such major concern, I just can't believe that pedal width (within
reason) is THAT important.
--

Cheers,

John B.


and that too...

I went for a bike fitting and the guy spaced my pedals OUT another couple
mm on each side, but he used ****ty spacers, so I removed them. I didn’t
recall it making a noticeable difference in either direction.

I was also hoping to buy a bike power meter that fit between your pedal and
your crank (and which kicked your pedals out another 3/4” or so, and there
weren’t many complaints about the Q factor - only the bait and switch when
the company decided they couldn’t actually build the product.