in message <[email hidden]>, David
(') said:I'm getting a bit overfaced here in this thread by the Metallurgy :-)
What I really would like to know is: for mountain bike use (XC and a
bit of rough treatment) on 85% trails 15% asphalt, can I save much
weight without compromising strength by investing in a composite or
titanium frame ?
Probably not enough to notice. The frame on Juliette's Santa Cruz
Juliana (full suspension, aluminium, large) weighs about 2450 grammes
including rear shock. Before it was built up I could easily hold the
frame vertically above my head holding onto just one of the rear
dropouts between finger and thumb. The frame on my Cannondale Jeckyll
(full suspension, aluminium, large) weighs about 2890 grammes
(according to Weight Weenies - I've never stripped the bike down to
weigh it).
By contrast, the all carbon-fibre frame of the EPX TerraShark, in medium
and without shock, weighs 2340 grammes, so it's probably actually
heavier.
There's a Ghost 'RT Scandium' which Weight Weenies report as weighing
1992 grammes including rear shock, but apart from that sub 2Kg 'large'
suspension frames which you can actually buy are very rare in any
material.
Quoted message said:If so, is it worth the premium such a frame would cost for a non-pro
rider. How much do these frames cost (by comparison)?
The lightest mainstream full suspension frames you can currently get are
probably the Scott Ground Zero frames - but they're being phased out in
favour of the Genius, which is a bit heavier[1]. Failing that, the
Scott Genius or the Santa Cruz Superlight. Under British conditions I'd
go for the Santa Cruz, because the Scott has its rear shock right in
front of the rear wheel where it will get covered in mud and be a
maintenance nightmare.
If you're really interested in saving grammes the weight difference
between an anodized Santa Cruz Superlight and a painted one is nearly
200 grammes - so go anodized. The frame will set you back £1200 list,
built bikes from about £2,300 upwards (Juliette's, last year, including
Hope Minis and some other nice bits, came in about £2500). It's a very
very very nice bike.
<URL:http://www.santacruzbikes.co.uk/completebikes/prices.html>
--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; single speed mountain bikes: for people who cycle on flat mountains.