Actually, from one point of view, TT is where weight should matter least, since one typically neither accelerates hard , not climbs. On the other hand , you're right that a superlight bike shouldn't actually hurt in a TT, since stiffness is not as important. I guess one could argue that for TT (at least short modern TT, as opposed to the very long ones in the British tradition) one may as well try to get that tiny edge of reducing rolling resistance, even though aerodynamics are a whole lot more important.
Regards,
Jerry Moos
> I am in general agreement with Jerry but would add time
> trial bikes to the list of those where lightening is
> generally beneficial and tends to have fewer detrimental
> effects; especially on pre-aero tt bicycles.
>
> Obviously, going too far can a big problem. Recall the rash
> of broken handlebars at a recent TDF team time trial. One
> rider (Millar?) in this year's TDF lightened his by having
> the FD removed on a single chainring crank and lost the tt
> by having the chain unship.
>
> Charlie Young
> Honeybrook, PA
>
> > We've had this discussion several time before. I'm in the
> > camp which maintains that the only weight which matters
> > much is the weight of the rims and tires, which have a
> > large moment arm around the center of rotation (the hub
> > axle). The weight of the frame and rider act at the
> > center of rotation and have essentially no moment arm at
> > all. The weight of the bike does contribute a bit to the
> > rolling friction on the tires, but the force required to
> > overcome rolling friction is trivial compared to that
> > required to overcome the aerodynamic drag on the rider's
> > body. In short, you expend lees energy drafting behind
> > someone on a 25 lb bike than riding in the wind on a 15 lb
> > bike.
> > Weight matters when climbing, as energy must be expended
> > to lift the weight against gravity. It also matters when
> > accelerating (force = mass x acceleration). But bicycle
> > road racing, unlike automobile road racing, does not
> > involve frequent hard accelerations. Theoretically, a
> > very light bike would be beneficial in field sprints in a
> > road race, in track sprinting, and in criteriums, but the
> > first two are typically the the domain of large, muscular
> > riders, who need a stiff frame to resist flexing more than
> > a superlight frame. Criterium specialists are also
> > concerned with frame stiffness. So mountain stages are
> > about the only place where a superlight frame may make
> > real sense, which may be why the top pro teams for decades
> > have tended to use superlight frames in just such stages.
> > Regards,
> >
> > Jerry Moos
> > Houston, TX