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