a pound off the wheels = two off the bike?

[gummibear]

Just to toss a spanner in the works, if you are riding a rolling hill type profile with short elivation periods, would it not be better to have heavy wheels? - Imagine the flywheel effect with mercury filled tubes!

 

Those wheels with the springs and weights

[Monark]

If lighter wheels do not make a difference then why do race cars run lighter flywheels and lighter rims?

 

I have just moved to a wheel set that is 800g lighter than my old set... the difference is amazing...

[FBSP]

Surely, if the weight of the wheels differ, rotational mass on a hill must favour the lighter wheels, especially as the hill goes on for a long time and doubly so if the gradient is steep. The heavier wheels would be ok if on a rolling set up (undulating profile) as the momentum is more, but from a standing start on a hill, the lighter wheels must be quicker, ie: a hill TT. An interesting debate none the less. I certainly agree that the test should be done a few times, not just once. Thanks for the interesting work SteveCT, more stuff like this and less rubbish on the hub would be great.

[chris_w_65]

If lighter wheels do not make a difference then why do race cars run lighter flywheels and lighter rims?

 

I have just moved to a wheel set that is 800g lighter than my old set... the difference is amazing...

 

Lighter rims is for less unsprung mass

 

Lighter flywheel is for more power and rpm and less torque

[Bennie Dikwiel]

Those wheels with the springs and weights

 

Pepetual motion - we going to make big bucks!!!!

 

[javadude]

This issue was discussed at great length a couple of years ago with the hub geniuses at each others throats for several days and many posts. There were qualified mathematicians, engineers and self taughts who went to great lengths to prove their theories and dis each others qualifications in the process.

[Starvin' Marvin]

I would thought a lighter flywheel makes it easier for a engine to rev up, less inertia faster rpm increase better accleration.

[stewie911]

Should make no difference where you take the weight off including yourself, coz everything has to accelerate or be kept in motion at the same rate.

Disagree, felt a massive difference on the hills when I got a better mtb, which weighed about 1-2kg less.

Can't even feel a difference going up hill when I lose 2 or more kg's.

[chris_w_65]

Disagree, felt a massive difference on the hills when I got a better mtb, which weighed about 1-2kg less.

Can't even feel a difference going up hill when I lose 2 or more kg's.

 

Placebo effect?

[Bat-ass]

its not hard to get definate answers to this mystery...

you need a power meter.. ride at a set power, say 250 watts.

First ride up a climb with heavy wheels, then up the same climb holding the exact same watts with the light wheels.... that will tell the diference...

 

Would be interesting to do the same over a few different terain examples??

I guess this is how they come to the numbers when they talk about "deep aero wheels" are "40sec faster" over 20 km flat course..??

[stewie911]

Placebo effect?

 

Let's go to the extreme.

 

Do you think someone that weighs 100kg riding a 10kg bike would ride a hill the same as when he loses 20kg and ride that same hill with a 30kg bike.

[chris_w_65]

Let's go to the extreme.

 

Do you think someone that weighs 100kg riding a 10kg bike would ride a hill the same as when he loses 20kg and ride that same hill with a 30kg bike.

 

He would lose the 20kg gradually and get used to less weight gradually and then you would suddenly slap 20kg on the bike so he would suffer.

 

Rather say ...

 

Would an 80kg guy with a 20kg backpack and a 10kg bike go up the hill the same as if he had no backpack and a 30kg bike?

[Johan Bornman]

The assumption is bull****.

[Caerus]

The assumption is bull****.

 

 

Bwah ha ha, lol.

[kosmonooit]

There's the whole mechanical dynamics of the spinning mass - gyroscopic moments etc will differ with wheel mass. Not going to make one go any faster down hill but surely will effect handling.

[Smiles]

what about the effect of the colour of the wheels - i know different bies are faster than others. black bikes are really fast, and really clean white ones with little bits of red detail may be even faster. orange and blue are downright slow