With this new OZ Superleggera weighing in at
7kg...

Does anyone know the *definite* weights of:

1) 17" OZ ST
2) 17" OZ Prodrive (P1 wheel)
3) OEM 5 spoke 16" alloy (name?!)
4) OEM 5 spoke 16" alloy in gold (just kidding!)

Would love to know weight of the OEM ready
for when I whack the Superleggeras on...
but I don't have one off the car without
a wheel on....anyone fancy weighing themselves and then
weighing themselves with an OEM craddled in their arms ?!

Mike.

 

Mike

Did last year some weighing by myself:

## OEM 16" wheel (my99): 7.25 kg (with E010 16.5 kg)
## OZ Superleggera 17": 7-7,5 kg
## OZ Supert. Evo II 17": 8.5-9 kg
## OZ P1-wheel 17": 9-9,5 kg,
## ScoobySport MIM 17": 10,5 kg

The other important thing is the ET;
for me is the choice between P1-wheel, with the better ET52, and the 2 kg less Superleggera with ET48...
I bought the P1, but then Superleggera was not there...

Tyres:
OEM Bridgestone RE010 (16"): 9-9,5 kg
Bridgest. 205-50-16 S02-PP : 9 - 9,5 kg
Bridgest. 215-45-17 S02-PP : 9,5 - 10 kg.
Bridgest. 215-40-17 S02-PP lm 8,5 kg

Don't know the weight P-Zero 205-45-17.

grt Geert

 

Wow!!! Excellent just what I wanted!!!
We really are a bunch of nerds! Still I found
someone who had more of a wheel-weighing
fetish than me!! Just kidding... :-)

Was hoping the OEM 16" alloy would weigh
more so that I'd notice going to the 7kg
Superleggera...!!! Oh well...spose you only
notice it if you go from a heavier 17" to
the lighter 17".

I thought some people in the Superleggera
thread were saying it felt twice as light
as say the OZ Supertourismo!!!

Thanks for the info...

 

Mike,

lol...

on the moment i have another ffffetishhhh:
an AP-22 Performance Meter; so many numbers to play with... and so much fun to collect that numbers...

....shlllliiisshh...

Geert

 

What is the relevance of the ET number ?

I ask as Mike Wood from ProDrive recently said they favour the P1 wheel's ET52 size.

Just wondering what the implications are ?
-DV

 

Good grief... I disagree with Don Palmer!!!!

On a circuit, unsprung weight makes little or no difference, except the centrifugal force of the wheel maybe affecting acceleration.

On a country lane, the difference is very important.

The heavier the wheel/hub/brakes, the more mass it is all thrown up into the wheel arch with and the more force must be used to arrest this movement and return it all to terra firma.

Until it is returned to the road, you have no grip. Important when cornering and braking on badly surfaced roads and this is a MAJOR effect on handling.

In fact the wheel does not even have to leave the surface to be "unweighted".

Then again, perhaps I can agree with Don in that if you have lighter components hanging off the corners, suspension reaction times are quicker and spring/damper rates can be reduced accordingly. By default, we have a better ride and better handling.

Anyone for Magnesium wheels at 4kg each? 400 to 600 a corner, but require regular inflating.

Thought not

ps Scoobysport KN's at 8.5kg

 

The implications relate mostly to ride - Ride is different from handling.

The ride improves when the ratio between the sprung and the un-sprung weight is maximised.

Light wheels mean better ride. – this is very important on very light-weight cars like the Sevens which are transformed by magnesium wheels.


Tyres are obviously important for handling - grip is a function of tyre construction, tread pattern and the materials used.

Bigger wheels mean bigger brakes can be fitted. This also affects un-sprung weight thus ride.

Engineering – pah!

who needs it?

Sorry

Don Palmer the wetter the better

 

Hi fello nerds! A few more numbers for you, measured on the bathroom scales (which SHE says weigh heavy! LOL).

Speedline ST2 9.2k
Radius R3 11.0k

On the unsprung-weight thing, 'effective' unsprung weight is greater the wider the wheels due to extra leverage - another reason for sticking to the recommended off-set.

Pete's reference to the new Scoobysport KN wheel is interesting. I think I am right in saying it is not only light but at 50mm ET is close to optimum. Does it clear AP 6-pots, Pete?

Question for techi nerds: it is easy to measure weight, but what about strength? Has anyone heard of wheels breaking? (It's certainly not unheard of in biking circles.) And bearings, too. I'm just trying to imagine the forces involved at a track day - an ordinary road car, shod with slicks and racing brakes slowing you down with a force equal to what, at least 1,000 bhp? A cracked spoke hardly bears thinking about.

But I am thinking about it. Is anyone else?

Hoppy

 

Hoppy thanks for the extra weight info.
I pressume these figures are without tyres and are both in 17"?

I'm gonna compile a table of wheels including offsets...see new thread.

Mike

 

Mike, sorry. Yes, both 17x7 no rubber. The table idea is excellent.

Hoppy

 

Anyone know the weight of a 17" Stilauto SR500?

 

Hi Hoppy

I have this wheel on the RA with AP 6 pots and there's huge clearance (see CCC article).

I suspect that we are talking about a lot more than 1000bhp, to reduce 1200kg of car with this much force. 120mph to 30mph in what... 3 seconds max, maybe 2??