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Old August 4th 20, 02:31 AM posted to rec.bicycles.tech
AMuzi
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Posts: 13,447
Default LBS owner's essay

On 8/3/2020 7:04 PM, jbeattie wrote:
On Monday, August 3, 2020 at 3:52:51 PM UTC-7, AMuzi wrote:
On 8/3/2020 1:08 PM, Sepp Ruf wrote:
wrote:
On Monday, August 3, 2020 at 9:40:20 AM UTC-7, sms wrote:
On 8/2/2020 6:27 PM, AMuzi wrote:

snip

I understood Mr Ruf to mean that a Sachs 2 speed of that era was
engineered with RH 10.5x26 thread.

I assume someone at F&S reasoned that your basic 9.5mm standard axle
would be less strong with a hole in the middle. Once that thread is
supported with tooling the next guy asks 'why not?'

Exactly.

+1

They no doubt found that 9.5mm was not sufficient with the
hole and determined that 10.5mm was optimal and didn't want something
as big as 12mm.

I guess they also found that 10mm was not sufficient. Who knows? And it
didn't really matter. They could specify the proper nuts to be
supplied.

They may have copied the Sturmey-Archer design but decided to go metric
instead of English and rounded up from 13/32" to 10.5mm.

When you engineer things you don't cut corners so that you need to
totally redesign something in the future. The 10.5 instead of a 12 made
about as much sense as your normal postings.

F&S were selling all kinds and sizes of hubs in the 1910's, including
"motor" hubs with 11, 13, and 14mm threaded axles, no threading details
known to me, unfortunately. Go ahead and ask Andrew or Aaron's how commonly
the 2 to 7 sp IGH's have failed because of 10.5 instead of 12mm. Eight
decades of engineers cutting corners was not what killed F&S. I only ever
broke any axles with the help of multi-sprockets freewheels, so I'm no expert.


F&S made all sorts of things including bayonets for a
succession of German armies[1]

I assume that, despite claims here on RBT, there just wasn't
enough volume to sustain their well designed well made but
esoteric bicycle designs. All the gearboxes made in a year
don't equal a day of Shimano derailleur production.

I see a lot of broken things but gearbox broken axles are
not among them. Freewheel hub axles yes, all the while.


I'm surprised to hear that. I've never broken a freehub axle. I broke some 5-6sp freewheel axles, but that's it.

-- Jay Beattie.


Yes we completely agree. Freewheel hub axles are very badly
cantilevered on the right side. Freehub (cassette) axles are
a much better design, as service history clearly shows.

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


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