Weight Less important than thought?

[956870733]

A lighter bike can help you sprint or breakaway as easy as possible. If you were a sprinter who frequently sprint, or say you were the ace who hide behind your teammate and sprint at the end of the day to win the stage for you and your team, you have to have a light one. If you were in a long individual tour, you have to have a heavier one(especially heavier wheel with more moment of inertia which could stock more rotational energy), then you can relax your leg for longer time without lots of speed drop by not spinning.

It's only my opinion.

 

[mikesbytes]

so after reading all the replies it just seems like weight, stiffness, and aero is not a big factor at all. then why do we spend thousands on our bikes? c'mon, there has to be a difference between the $600 bike and the $6000

It really depends on what you are using your bike for. If you are commuting, then its no big deal. If you are a top racer then you could loose a race by half a wheel.

In the end, the most important part is the nut behind the handlebars.

 

[956870733]

Some more comment, for heavier bike, more energy will be transfer into heat when you are braking. That means you are wasting bio-energy of your own.

At high speed cornering, especially in downhill, you need a tyre with better grip on its side for your heavy rear wheel to provide more centripetal force. I'm saying this: you have to be more careful at the corner riding a bike with heavier rear rim(or say disk wheel) in a rainy day. (correct me if you are good at mechanical physics)

 

[531Aussie]

A guy on Bike Forums took these aero numbers out of Tour Magazine.
They tested Uwe Peschel with all the different aero bits.


Required output to maintain 45 kph on a:

Standard road bike, hands on hoods = 465 Watts
Same bike, hands down on the drops = 406 watts
Same bike with aero bars = 369 Watts
Same bike, triathlon position (5.5 cm lower bar, saddle forwards)= 360 Watts
Same bike, as above, with 2 tri spoke wheels = 345 Watts

Cervelo TT bike with 2 tri spoke wheels = 328 Watts
Cervelo TT bike with tri spoke front & disk rear = 320 Watts
Cervelo TT bike, tri spoke front & disk rear + aero helmet = 317 Watts
Cervelo TT bike, same as above + skin suit = 307 Watts
Cervelo TT bike, same as above, with saddle pushed back 3cm = 293 Watts

From 465 to 293 watts!! That's obviously a reduction of 172 Watts just from aero stuff, and the suggestion is that the aero Cervelo TT frame made a difference of 17 Watts

 

[pistole]

A guy on Bike Forums took these aero numbers out of Tour Magazine.
They tested Uwe Peschel with all the different aero bits.


Required output to maintain 45 kph on a:

Standard road bike with road bars = 465 Watts
Same bike hands down on the drops = 406 watts
Same bike with aero bars = 369 Watts
Same bike, triathlon position (5.5 cm lower bar, saddle forwards)= 360 Watts
Same as above with 2 tri spoke wheels = 345 Watts

Cervelo TT bike with 2 tri spoke wheels = 328 Watts
Cervelo TT bike with tri spoke front & disk rear = 320 Watts
Cervelo TT bike, tri spoke front & disk rear + aero helmet = 317 Watts
Cervelo TT bike, same as above + skin suit = 307 Watts
Cervelo TT bike, same as above, with saddle pushed back 3cm = 293 Watts

From 465 to 293 watts!! That's obviously a reduction of 172 Watts just from aero stuff, and the suggestion is that the aero Cervelo TT frame made a difference of 17 Watts

- very interesting read.

- thanks for posting that up.

- have noticed that , by just changing position from the hoods to the drops (and maintaining similar amount of effort) , the speed will pick up by a couple of kmh.

cheers.
.

 

[mikesbytes]

Was wondering about the 14 watt gain by putting the saddle back 3cm. Is that a pure gain, or does the body become less efficent put putting the watts out negating the gain

 

[sogood]

The study measures the power output required to maintain a constant 45kph. So it has nothing to do with the effect of posture on power output.