Just been looking into this as i am looking to lose weight on the car (me as well :tongue: )

 

Been onto the wheel place which i got my wheels from and the new wheels are 2kg's lighter than my old wheels which in rolling radius works out to 14/1 so if you work it all out ie 2kg savings per wheel times 4 = 8kg savings on wheels then times that by 14 = 112kg rolling weight saving which i would imagine would make quite a big difference :cool:

 

Some bugger buy my wheels :nana2:

 

Mike

What are the new ones you're getting and out of interest how much do they weigh?

What does that mean "in rolling radius works out at 14/1" ?

Fitting lighter alloy wheels will reduces the car's unsprung weight - in layman's terms this means a reduction in rotating mass at the ends of your suspension components, giving you improved performance, steering feel and greater braking response.

Yes, but where does the 14/1 bit come in?

Yes, but where does the 14/1 bit come in?

 

not quite sure on the full explaination but it means for every say 1kg you save on each wheel its the same as saving 14kgs on the total weight of the car. Its all to do with rolling weights etc i dont totally understand it myself :p

its to do with centrifugal forces. same reason why people go for lightweight fly wheels and UD pulleys. it doesnt just save a few pounds of weight

Reducing unsprung weight is one of the most critical factors affecting a vehicle's road holding ability. Unsprung weight is that portion of a vehicle that is not supported by the suspension (i.e. wheels, tires and brakes) and therefore is the most susceptible to road shock and cornering forces. Therefore reducing unsprung weight has more effect than reducing "sprung" weight as the tyre itself has less dampening to accomplish.

 

Hope that makes some sense to you.

There is quite a good article on it here which explains it a bit more technically.

There's 2 seperate things going on here.

One is that reducing unsprung weight is good as it allows the tyre to stay in contact with the road better over bumps etc.

 

The other is that taking, say 2kg off a wheel actually has more apparent effect than just the 2kg, as the engine has to accelerate the wheel forwards, and also accelerate it rotationally.

I first heard of this when I was designing rotor head components at Westland Helicopters, and decided to prove it for myself.

 

It turns out that, assuming an average type of wheel etc. that saving 2kg on a wheel equates to about a 2.4kg loss from the vehicle.

So unfortunately your 8kg loss is the same as losing only about 10kg from the car.

 

Or looking at it another way, the force to accelerate the wheel rotationally is negligible compared to the force to move it forwards.

When I got my 17" Volk Racing Challenge i decided to weigh them compared to my stock wheels, they weighed 1kg less each wheel/tyre considering the rim had gone up 1" in diameter, 1/2" in width and tyre also was 10mm wider. Not bad methinks :)

 

But as to what they weigh........ I cant remember figures now :o