How much does weight influence performance?

[pastapouch]

Wat? S? jy ons Vets is stadig?

 

Vets??? Afrikaans / Engels

In Engels kort vir Veteran????

In Afrikaans is dit kort vir Vetties? 

 

[AuctionLamb]

I lost 9kg's and can feel the difference on flat and hills!!!

 

I would rather be a less heavy(climber) cyclist than a heavy(sprinter). In CPT there is so little flat races so not worth to be a pure sprinter.

 

To lose that much weight I'd have to have a testicle removed. Hey' date=' maybe the saddle would be more comfortable after that too!

[/quote']

 

I actually picked up the 11 kg cause JHB was good to me......just 2kg to go....

[Gumpole]

I lost 9kg's and can feel the difference on flat and hills!!!

 

I would rather be a less heavy(climber) cyclist than a heavy(sprinter). In CPT there is so little flat races so not worth to be a pure sprinter.

 

I think if you are overweight the benefits in losing extra fat far outweigh the actual loss of the weight.

 

Sias, I am not saying that the Vets are slow, just that if you take a TT up one of the Alpine climbs there will be a bit of a gap between the top Tour contenders who normally win with a performance of 1800m/h, and a SA 'elite' rider and 'Vet'

 

So maybe it should be 6% for LA at his peak, 5.5% for top SA climbers, 5% for good vet climber, 4% for B/C start rider, 3% for me , 1% for the 6hr argus rider.

[Johan Bornman]

Snip.....

Dis ook nie net die gewig nie' date=' maar ook waar dit verloor word. As jy bv 1kg op die wiele verloor, gaan dit jou baie meer baat as om 1kg op die raam te verloor. Die wiele beweeg en die raam is staties relatief tot alle dele op die fiets. Jy het baie minder energie nodig om bv 'n Zipp 202 (1050g) aan die draai te kry en aan die draai te hou as 'n Mavic Open Pro met 32 speke (1900g). Op 'n 13km klinm gaan jy definitief die verskil agterkom en in die tye sien.[/quote']

 

Sias, I can't blame you for repeating the stuff you read in bike magazines and hear from other people who heard it from someone who read it in a bike magazine. In the PR business, they know that if someone hears something three times from three different sources, it is considered as the gospel truth, and they design PR (publicity) campaigns around that.

 

But back to physics. The notion that weight saved on a wheel is somehow more valuable than weight saved on the bike or body, is pure nonsense. The effect is so miniscule, in the order of less than one half a percent for an 85kg rider and bike losing say 400grams on the wheel, that it is completely negligible. Weight is weight, save it and you gain. Weight (saved) on a wheel is jsut weight saved.

 

Further, you say (and I translate) that "and to keep it turning", making the case that to keep a heavier wheel turning requires more energy. It doesn't. Once the wheel is turning, the only energy lost is through friction and a lighter or heavier wheel has similar friction - rolling resistance, bearing friction and aerodynamics (assuming the same profile etc). The fact that a lighter wheel perhaps has less spokes will make it more aero, but your statement of "to keep it turning" is not true.

 

 

 

[epoh]

I lost 9kg's and can feel the difference on flat and hills!!!

 

 

 To lose that much weight I'd have to have a testicle removed. Hey' date=' maybe the saddle would be more comfortable after that too!

[/quote']

 

 

 

 

 

erm.. as gifted as you are, imagine if you loose both testicles!@# that would save you 18kg in weight

 

 

 

 

[Sean]

I lost 9kg's and can feel the difference on flat and hills!!!

 

 To lose that much weight I'd have to have a testicle removed. Hey' date=' maybe the saddle would be more comfortable after that too!

[/quote']

erm.. as gifted as you are, imagine if you loose both testicles!@# that would save you 18kg in weight

 

Don;t think I haven't contemplated that

I made the mistake of mentioning the idea to my wife (she was all for it actually. can't imagine why )

[AuctionLamb]

I lost 9kg's and can feel the difference on flat and hills!!!

 

 To lose that much weight I'd have to have a testicle removed. Hey' date=' maybe the saddle would be more comfortable after that too!

[/quote']

erm.. as gifted as you are, imagine if you loose both testicles!@# that would save you 18kg in weight

 

maybe he want's to belike Lance A??

[Guest colonel]

Ask Fatty he can tell you it makes a difference.

[Groot Lem]

So if I lose a kg on the bike is the effect the same as a kg off my body weight??

[RobMobius]

Yes and no.

 

If you lose a kg of non functional mass such as fat, hair, skin (fell on Sunday and feel like I have lost a Kg of skin!) the result is the same as losing a kg of bike weight. The bottom line is you have less weight to drag up a hill.

 

If you lose a kg of functional weight such a leg muscle then you have effectively reduced that which you need to get you to the top of the hill.

 

Bluntly put, if you needed your Honda Civic to climb a hill quicker then it makes sense to make the car lighter by ripping out seats, spare wheels etc. But if you lighten the car by putting in a smaller engine then the gains will be neutral or even negative.

 

[Johan Bornman]

Yes and no.

If you lose a kg of non functional mass such as fat' date=' hair, skin (fell on Sunday and feel like I have lost a Kg of skin!) the result is the same as losing a kg of bike weight. The bottom line is you have less weight to drag up a hill.

If you lose a kg of functional weight such a leg muscle then you have effectively reduced that which you need to get you to the top of the hill.

Bluntly put, if you needed your Honda Civic to climb a hill quicker then it makes sense to make the car lighter by ripping out seats, spare wheels etc. But if you lighten the car by putting in a smaller engine then the gains will be neutral or even negative.
[/quote']

 

Well explained.

 I just want to emphasise that the 1kg, even if lost from the wheels, has no different effect than that lost from your bike or your spare tyre around your waist.

 

 

[GoLefty!!]

Yes and no.

If you lose a kg of non functional mass such as fat' date=' hair, skin (fell on Sunday and feel like I have lost a Kg of skin!) the result is the same as losing a kg of bike weight. The bottom line is you have less weight to drag up a hill.

If you lose a kg of functional weight such a leg muscle then you have effectively reduced that which you need to get you to the top of the hill.

Bluntly put, if you needed your Honda Civic to climb a hill quicker then it makes sense to make the car lighter by ripping out seats, spare wheels etc. But if you lighten the car by putting in a smaller engine then the gains will be neutral or even negative.
[/quote']

 

Ah again assumptions. A smaller engine is not necessarily less powerful since it has less friction. Also ligter pistons and possibly requiring less fuel to do the job all translate into perhaps little drop in actual performance.

 

The key to going faster is Power to weight. How many watts per kilogram can you produce. Now this does not mean that you need to rush out an buy a powermeter, occasional access to one will do.

 

Loosing mass off you body in the right areas will be beneficial. Even loosing it off you legs will benefit you as long as you are loosing more power than you are loosing weight.

 

Remember the rider is the engine. Efficiency of using fuel and hence the power output is the best way to gauge performance increase for any moving object.

 

Since in an engine e.g, lightening the moving parts allows higher revs, it stands to reason that lightening the bits that make the wheels tun will have benefits in reducing fatigue (Less mass to decelerate at the end of the stroke and less to accelerate) and you should be able to get higher rpm and therefore more power. The push on the pedal is also important but again like in a car engine, if you can keep the bnag going till the pistons starts to come back up then you are making best use of the energy available, hence if you can applu force to the pedals through a better pedal stroke you produce more power through the stroke and you go faster.

 

forget about the bike weight. Look at the total mass and the rotating and reciprocating masses. This is where the biggest gains are.

 

 

[RobMobius]

"Ah again assumptions. A smaller engine is not necessarily less powerful

since it has less friction. Also ligter pistons and possibly requiring

less fuel to do the job all translate into perhaps little drop in

actual performance."

 

--------   This represents a hair

 

-------<  This represents a split hair

 

At a basic level, reducing weight by non functional mass is better than losing weight from functional mass such as muscle.

 

I think what the previous poster is trying to say is if you can reduce body weight, possibly by losing muscle mass, but still retain the same power output you will increased your power to weight ratio which should make you a better climber.

 

Will it make you be able to "rev" faster or cycle with a higher cadence? Not directly no. take a look at the builds of the sprinters (running and cycling). No lack of muscle mass there.

 

Leg speed is determined by a host of factors. The most obvious one after training techniques is the muscle fibre type that dominates. A dominance of white muscles fibre means a faster muscle, more powerful muscle contraction over a short distance. Red fibre types are slower and less powerful but have far more endurance. This brings up an interesting debate on which will make you a better climber? I propose a dominance of red slow twitch fibres.

 

[Johan Bornman]

Yes and no.

 

Ah again assumptions. A smaller engine is not necessarily less powerful since it has less friction.

 

Oh for goodness sake Tim. Stop it. The world revolves around assumptions and any sane person keeps those in mind. If we were to write everything will dozens of disclaimers and lists of assumptions we'll get nowhere fast.

 

[

Loosing mass off you body in the right areas will be beneficial. Even loosing it off you legs will benefit you as long as you are loosing more power than you are loosing weight.

 

I don't think so......

 

 

forget about the bike weight. Look at the total mass and the rotating and reciprocating masses. This is where the biggest gains are.

  

 

Tim, you keep on sneaking in this apparrently innocuous and innocent line. However, you are wrong, no matter how many times you say it. I think it is time you do the homework and show the math to prove your point.

 

Let me repeat: Rotating mass make no more of a difference than mass elsewhere on the bike!

 

Assumptions: Anything under 1% is enough to effectively discard in the practical world.

 

 

Johan Bornman2007-08-29 12:10:04

[bruce]

Assumptions: Anything under 1% is enough to effectively discard in the practical world.

 

Unless of course, the performance differential between the two situations you are comparing is of the order of a single percentage point.  Then an absolute value of 1% change becomes huge in relative terms

[PokerFace]

Get a healthy sustainable diet and a good training program. Spend as much time as you can on your bike (with good training program) and you are 90% there. Then go and buy the lightest bike you can afford and that is your optimum weight/power to weight etc.!!!! If that is not enough for you. Become a weight weenie like Rasmussen and look like death warmed up and become miserable, because you are always hungry.