SP12 Wheel Weight Saving
Discussion
Whilst adjusting the damping yesterday, I thought whilst my SP12's were off I'd weigh them.
My 18" SP12 from Silverstone with Toyo's running 255's weight 18kg. I checked my old TVR 16" Saturn’s with 225s. They weigh 18kg as well
What happened to my 25% weight saving?
I can only conclude that original TVR 18" Spiders are heavier than SP12's and the original Saturn's.
Therefore does a 16” Saturn shod Cerb accelerate faster than a 18" Spider Cerb?
My 18" SP12 from Silverstone with Toyo's running 255's weight 18kg. I checked my old TVR 16" Saturn’s with 225s. They weigh 18kg as well
What happened to my 25% weight saving?
I can only conclude that original TVR 18" Spiders are heavier than SP12's and the original Saturn's.
Therefore does a 16” Saturn shod Cerb accelerate faster than a 18" Spider Cerb?
Edited by johnbear on Friday 15th December 09:00
Can I hijack this thread a little by asking if someone can explain to me in simpleton terms how a saving of 12kg in total (3kg per wheel) would equate to shaving off a much larger weight (36kg I believe in a another thread) elsewhere from the car. This is on the basis of moving from the original 18 inch spiders over to the Silverstone SP12 wheels. I ask as I really like the look of the SP12's especially after seeing them in the flesh fitted to the Boss's Cerb at the VW meet.
The theory is that every kilogram taken off the unsprung weight is worth 3kg off the car in handling terms. It's to do with the inertia under acceleration and braking of unsprung weight. It's not 36kg physically removed, the effect of 12kg off the unsprung has the *same effect* (apparently) as taking 36kg from the sprung weight. Somebody more erudite than I (Trackcar?) could explain it better I'm sure.
I'd never given the weight saving much though but I had expected some saving over the Saturns, if only a small amount.
I'd presumed the tyres on a 16 are heavier than an 18 due to the increased sidewall on the 16's (I haven't put the SP12 225 from the front on the scales yet). I expected the Saturns to be made of a heavier alloy than the SP12's, therefore I thought a saving small saving might exist with the SP12's over the Saturns, even though they are bigger.
But I didn't expect them to be exactly the same (within reason of my bathroom scales).
However, they are fanastic looking wheels. The only shame is I caught the alloy rim against the road going down the hairpins on Stelvio. The force going into the corners must have been too much for the tyre sidewall.
I'd presumed the tyres on a 16 are heavier than an 18 due to the increased sidewall on the 16's (I haven't put the SP12 225 from the front on the scales yet). I expected the Saturns to be made of a heavier alloy than the SP12's, therefore I thought a saving small saving might exist with the SP12's over the Saturns, even though they are bigger.
But I didn't expect them to be exactly the same (within reason of my bathroom scales).
However, they are fanastic looking wheels. The only shame is I caught the alloy rim against the road going down the hairpins on Stelvio. The force going into the corners must have been too much for the tyre sidewall.
BossCerbera said:
Neil P said:
Depends how much the driver weights, and how many sticky buns they've eaten.
Look on the bright side - if your car's on spiders now, you can eat another half-a-person's weight in sticky buns if you move to SP12s.
Well, they're not going to fecking help me much Phil!
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