tobold.org

correct • elegant • free

△ Cam.misc △

◅ Safer driving and cyclists

lightning ▻

Cycle & pedestrian railway bridge, council comment?

In article <199511291219.MAA07044@sun1.cup.cam.ac.uk>,
Paul Treadaway  <pt100@cup.cam.ac.uk> wrote:
>I'm a little confused by your comment about 3 gears. Surely the problem
>with Sturmer-Archer geared bikes is the lack of high ratio gears for the
>long flat stretches in Cambridge, or conceivably the lack of intermediate
>gears, but there's nowhere in Cambridge requiring a gear lower than the
>lowest ration gear of a Sturmer-Archer is there?

This is meaningless.  The hub gear fixes the relative ratios of
the available gears (although I'm reasonably sure that there are
"wide" and "narrow" versions of the 3-speed hub, and Sturmey-Archer
(sic) have been producing various 5-speed hubs for some years now),
but the absolute gearing, measured in inches of road travel per
revolution of the pedals, depends on the ratio of the numbers of
teeth on the chainwheel and sprocket.

The gearing also depends on the size of the rear wheel, and how
hard it is to push the pedals depends on the gearing and the throw
of the cranks, but these variables are more or less fixed by the
geometry of the bike.

If your hub gears are too low, get a chainwheel with a couple more
teeth, or a sprocket with a couple fewer.

Tim.
--
Tim Goodwin   | "After all, what did Brunel, Watt, Boulton and
Unipalm PIPEX | Telford do that was complex?  I could have built
Cambridge, UK | the Great Western Railway on my own." -- Ian Batten

Original headers:

From: tim@pipex.net (Tim Goodwin)
Newsgroups: cam.misc
Subject: Re: Cycle & pedestrian railway bridge, council comment?
Date: 30 Nov 1995 11:09:52 GMT
Organization: Unipalm PIPEX
Message-ID: <49k3e0$2o5@wave.news.pipex.net>
References: <49f11f$pbc@doc.armltd.co.uk>
  <49fauu$cqp@lyra.csx.cam.ac.uk>
  <199511291219.MAA07044@sun1.cup.cam.ac.uk>

△ Cam.misc △

◅ Safer driving and cyclists

lightning ▻