Re: [CR]"Whats the beef about bondo?"

Dale,

I'm sure most restorers of bikes use some sort of spot putty and

catalyzed body filler; but in very small amounts. Filling small

pinholes, rust pitting, and such on old bikes. The material used in

large quantities and in thick layers on parts of the bike frame that

tend to flex is not good application of the material. But it is the

only "practical" way to finish off a bike designed like the ones we

have been speaking about. Personally I don't have a real problem with

using bondo to finish a bike designed like the ones we're talking

about provided the layers are not thicker than the material can

withstand in actual use. What I found "odd" about the design and

construction in question is the amount of very heavy brass used in the

making of the faired in parts. It makes the frame very heavy, which to

me is contrary to the purpose of an aerodynamic bike intended for time

trials. Besides the fact that "aero" tubes need to be much heavier

gauge in the first place to have any hope at all of being rigid enough

for effecient power transfer. Round tubes are more aero than teardrop

tubing (or round tubes with farings) 94% of the time. In other words,

aero tubes are only more effecient when going directly into the wind

and within a few degrees of directly into the wind. I believe it has

been established that it comes down to about 6% of the time while on

the road. The position of the rider is by far the most important

factor when trying to become aerodynamically effecient. The rider

represents 90% of the drag of the bike/rider combo. A reasonably light

frame with round tubes and components that are properly designed for

effeciency at TT speeds are a much better approach. Work on the rider

instead of obcessing about an aero frame. That's my opinion, FWIW.

Brian Baylis La Mesa, CA Since real bikes are for performance of the task at hand. I personally

don't award design kudos for bikes that fail that test, regardless of

how interesting or beautiful they look. The KD laser track sprint bike

is to me a whole different animal. I'd have to study it further, never

having seen that before; but THAT bike appears to be a genuine work of

art and design, IMHO.