Unsprung Weight Increase !

[concordepilot19]

I had one of my original steels fitted temporarily during an alloy refurb and was surprised to notice that the alloy weighed more than the steel ! Bathroom scales confirm that the 15" steel plus tyre was 15.5 kg and the 16" alloy plus tyre 18 kg. That sounds like a 10kg increase in unsprung weight in total, should I be surprised / concerned ? The wider section / lower profile is a bit more stable / less wallowy on the road, but apart from that it's down to looks alone !

 

[Will]

The alloy wheels should also help with cooling the brakes I believe

Oh, and they look much better

 

[jgevers]

Hi,

2.5 kg per corner is not to bad. Expect slightly less control from shock but probably not noticable on the road. Slightly increased wear on ball joints, bushes and bearings because of increased weight and increased grip. Probably a bit lumpier over uneven surfaces due to increased weight and lower profile tyre.

On the whole I wouldn't worry about it.

regards,

Job

 

[Satch]

The unsprungweight includes wheels and tyres, hubs, brakes and stuff not supported wholly by the springs, so you add in a percentage of the weight of steering and control arms etc etc. that connect to the unsprung bits.

So the weight difference here is not going to be material.