On 10/24/2018 5:59 AM, Emanuel Berg wrote:
Today there was a gorgeous open-frame steel
bike from the 60s or 70s, with the favorite
635 tires.

The only wrench in the machinery is that it has
rear-facing dropouts, and the o-bolts to grab
the rear wheel axle to tighten the chain were
missing. If it ever had any! Or were they
always there on such bikes?

I think such, now exotic spare parts can be
difficult to find... Can you get away
without them?

I read [1] that on track bikes, also with
rear-facing dropouts, they don't have them (the
o-bolts). But I suppose people set the tension
before every race! I also read that track bikes
do not have QRs, because "threaded nuts will
hold the chain tension far longer", and that
such bikes have a more robust, 1/8in chain.
I bring this up because it seems to contradict
what was said in another thread that QR is
stronger than nuts. Obviously, people don't
race track bikes as others do commuters!
Unless I'm missing something else (I never even
saw a track bike IRL).

BTW aren't all nuts "threaded"? Except those
who participate in reality TV shows...

[1] page 188 in
@book{complete-road-bike-maintenance,
author = {Guy Andrews},
ISBN = {978 1 4081 7093 9},
publisher = {Bloomsbury},
title = {Complete Road Bike Maintenance},
year = 2013
}


Chain tensioners are handy on roadsters to get the wheel
centered what with full mudguards, chain case, stirrup brake
and so on before tightening the axle nuts. They are not
necessary by any means and in fact the #1 problem with them
is riders setting chain tension too high which causes
excessive chain and bearing wear.

A QR holds as tight or tighter than axle nuts but either are
adequate especially on single speed where the gearing is not
as low as touring setups. Racing rules for track prohibit
QR. That and tradition are why real track bikes use solid
axles. (My own fixie is QR, never posed any problem whatsoever))

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