Hi CR folks,
This list has so many folks that jump on people for so many things - but NOBODY on list commented that my analysis in my 753 response was just PLAIN WRONG! It is a tad scary that the only thing that is truly fact based (physics) didn't get a peep - except for an old friend who set me straight off-list.
According to my friend (and it appears that formulas I found confirm my error), torsional rigidity is effected by diameter to the third power and is directly effected by tube guage.
So - a 1.25" tube with .4mm wall thickness has more torsional rigidity than a 1.125" tube with .5mm wall thickness, but both have less torsional rigidity than a 1.125mm tube with .6mm wall thickness.
The upshot is that tube guage DOES matter for torsional rigidity and you can tune using either tube guage or diameter.
Mike Kone in Boulder CO
> The fact that older Waterfords and a Raleigh team may share 753 tubing is nearly
\r?\n> meaningless. The Waterford uses oversize tubing which makes for a very
\r?\n> different ride. Torsional rigidity is essentially determined ONLY by tube
\r?\n> diameter - with tube wall thickness being of no practical concern. So while you
\r?\n> can tune frame rigidity with respect to side deflection by altering guage, you
\r?\n> can't use an oversize tube and reduce torsional rigidity by making it lighter.
\r?\n> Not that this is a bad thing, it just makes things different. Some folks may
\r?\n> prefer oversize tubes, others like skinny tubes - and I do believe that oversize
\r?\n> tubes transmit road shock differently (in a way that I often like).
\r?\n>
\r?\n> To duplicate the ride of the Raleigh 753 team (if that is what you wish to do),
\r?\n> then perhaps aquire some kind of lightweight skinny tube frame. The current
\r?\n> offerings from true temper actually allow for some very lightwight options.
\r?\n>
\r?\n> Another possibility is to track down an actual 753 tubeset and "clone" the
\r?\n> Raleigh team. I know that Mark Nobilette is sitting on a few sets (but I'm
\r?\n> hoping to have him do some fresh Rene Herse bikes with the materials at some
\r?\n> point).
\r?\n>
\r?\n> Also remember that many Team 753 bikes use the Continental (french) diameters
\r?\n> and this perhaps impacts the feel of the frame as well - with the seatube and
\r?\n> downtube being a smidge smaller and the top tube being a smidge larger).
\r?\n>
\r?\n> Now it is very possible to make a very lightweight lively frame with oversize
\r?\n> tubes (such as Waterford uses), but it will ride somewhat different than the
\r?\n> skinny tube bikes. Years ago I motivated Waterf ord to introduce the RS 22T
\r?\n> which I think was among the very best of the road sport type models (their other
\r?\n> models did not have enough front center to really use fenders despite their
\r?\n> claims). For my taste, the RS22T worked wonderfully (in around the 56-58cm
\r?\n> range) but of course, it is all very subjective.
\r?\n>
\r?\n> Hope these ramblings help.
\r?\n>
\r?\n> Mike Kone
\r?\n> Rene Herse Bicycles Inc.
\r?\n> Boulder CO
\r?\n>
\r?\n> -------------- Original message --------------
\r?\n> From: Steve Kurt
\r?\n>
\r?\n> > hi gang,
\r?\n> >
\r?\n> > I've got a early 80's Raleigh Team, built with Reynolds 753 tubing.
\r?\n> > It's a lovely bike, with superb craftsmanship. Possibly the best
\r?\n> > production frame made??
\r?\n> >
\r?\n> > For better or worse, it's my fastest bike, so I tend to ride it
\r?\n> > frequently. There are days, when it's hot and I'm sweating a lot, that
\r?\n> > I'd rather be riding a bike that I didn't worry as much about. For that
\r?\n> > reason, I've been thinking that a Waterford built from 753 might be a
\r?\n> > good bike for those rougher conditions.
\r?\n> >
\r?\n> > A Waterford 1250 in my size was available on ebay recently, and I was
\r?\n> > seriously tempted. My only question was whether it would ride similarly
\r?\n> > to the Team, especially in terms of weight and stiffness. The Team
\r?\n> > strikes me as being a rather light frame, especially since I ride large
\r?\n> > frames.
\r?\n> >
\r?\n> > Does anyone know how the two compare? Or does anyone have a 61cm c-c
\r?\n> > seat tube, 58cm c-c top tube 753 frame available??
\r?\n> >
\r?\n> >
\r?\n> > regards,
\r?\n> > Steve Kurt
\r?\n> > Peoria, IL