in message <[email hidden]>, David Waters
(') said:What is a compact and what are the advantages/disadvantages?
Long ago, bicycles were made of steel and tubes were generally of small
diameter. Because the seat post was of steel and of small diameter if
you exposed a lot of it it would flex. So frames were designed with
horizontal top tubes, in order to reduce the length of the exposed seat
tubes. The range of practical adjustment was quite small, so many sizes
had to be made and stocked, meaning that manufacturers had quite a lot
of capital tied up in stock.
Nowadays bicycles are often made of aluminium, with larger diameter
tubes. So the seat post can be of larger diameter and hence stiffer. So
you can expose more of it without excessive flex. So you can make bikes
with sloping top tubes which give a lot more adjustment. So you don't
have to make so many sizes. These bikes with sloping top tubes and
yards of exposed seat post are called 'compacts'.
Two benefits: the manufacturers save money, so the bike may cost less.
And in an unplanned dismount you're less likely to come down hard on
the bar with your wedding tackle.
--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
I shall continue to be an impossible person so long as those
who are now possible remain possible -- Michael Bakunin