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Model specific boards => Golf mk6 => Topic started by: CHB100 on 18 June 2011, 14:45

Title: Wheel & Tyre weights!
Post by: CHB100 on 18 June 2011, 14:45
Have just removed 17" Monza's and replaced with 18" DOTZ exiles (Pics above) and weighed each, guess

what.........

17" Monza with Dunlop 245/45 R17 circa 5mm tread  =  23KG

18" DOTZ Exile with Contisport 3 225/40ZR18 circa 7mm tread = 20KG

So that's 3KG a corner!! Alloy wheel weight or tyres (rubber & canvas) are heavier than you think?

So an unsprung weight saving of 12KG, will it be noticeable?
Title: Re: Wheel & Tyre weights!
Post by: am1w on 18 June 2011, 15:33
Every little bit counts. Possibly one of the reasons SteveP bought the wheels.
If you look at my Summer Tyre Sticky you'll find that Conti tyres are probably the lightest. Perilli are quite light too. Can't check as I am away from home having a haircut!
Glad you like the wheels. We were all careful owners!
Title: Re: Wheel & Tyre weights!
Post by: Exonian on 19 June 2011, 15:54
When I picked up one of my BBS CKs my back nearly snapped.
When I picked up one of my ex SteveP Pro Races it was as light as a feather (f**king big heavy aluminium and rubber feather though). So you can see the motorsport heritage there, every unsprung kilo saved is worth quite a bit of sprung kilo-age.

Not very scientific but a fact.
Title: Re: Wheel & Tyre weights!
Post by: Hurdy on 19 June 2011, 17:27
1kg off the unsprung rotating mass is the equivalent of 5kg from the sprung static weight of the car. Rotational inertia plays a big part in acceleration, deceleration and cornering of a car. Ascari used carbon fibre Dymag alloys on their cars and found that it reduced the 0-60mph times and lap times by a significant amount.

The 17" Monza's weigh just over 11kg on their own, compare that to OZ Alleggerita's at 6.4kg each.

That equates to 4.6kg a corner or 18.4kg for the car. Multiply this by 5 and the effect on the car is like removing 92kg from the sprung static weight. :cool:

Tyres can be around 1-2kg different in weight depending on the compound and the inner wall make up. Some use kevlar reinforcing for the sidewalls now instead of steel braiding as it is stronger AND lighter. :smiley:
Title: Re: Wheel & Tyre weights!
Post by: R32UK on 19 June 2011, 20:17
I think the bbs on my car at the moment probably weigh twice as much as one of the monzas  :laugh:

i dont avoid potholes.. i make them :laugh:
Title: Re: Wheel & Tyre weights!
Post by: ajmoir36 on 19 June 2011, 21:38
Whats the weight of a Vancouver then?

Waht about strength?, I had some Kahns (once) and they bent in a pot hole like cheese.
Title: Re: Wheel & Tyre weights!
Post by: am1w on 19 June 2011, 23:46
Ajmoir makes a very good point about strength.
Today, my nearside front 18" Monza Shadow hit a massive pot hole, nay a crater, on the A40. There was no way to avoid it. However, I managed to avoid the massive lump of tarmac that lay alongside it. Must admit I was canning the car a bit.
I felt sick to the stomach when this happened and prayed to all the relevant gods for my beloved Monza and not so loved Bridgestone not to be wrecked. My prayers were answered this time. Never needed a drink afterwards so badly!
Tough wheel that Monza Shadow, but possibly not very light. Fine by me! :smug:
Title: Re: Wheel & Tyre weights!
Post by: Ess_Three on 20 June 2011, 02:45
Ajmoir makes a very good point about strength.
Today, my nearside front 18" Monza Shadow hit a massive pot hole, nay a crater, on the A40. There was no way to avoid it. However, I managed to avoid the massive lump of tarmac that lay alongside it. Must admit I was canning the car a bit.
I felt sick to the stomach when this happened and prayed to all the relevant gods for my beloved Monzza and not so loved Bridgestone not to be wrecked. My prayers were answered this time. Never needed a drink afterwards so badly!
Tough wheel that Monza Shadow, but possibly not very light. Fine by me! :smug:

Alloy used, construction and design all come into play for strength...
It's fairly well known that a cross-spoke design is about as strong as any, whilst straight spokes tend to be a bit lighter, whilst forged construction tends to be stronger than cast, and flow formed in between the two.
Unless you go to exotic construction and higher quality alloys, it's difficult to keep the price down, the weight down, yet keep the strength up.

I remember bending a front strut on a Mk3 Golf whilst the BBS RX wheel was out of round by less than 0.5mm...
Whilst on my ITR I gave a featherlight Enkai wheel a good smack and was left with this:

(http://i188.photobucket.com/albums/z72/Ess_Three/Wreckedwheel1-1.jpg)

Title: Re: Wheel & Tyre weights!
Post by: am1w on 20 June 2011, 07:56
That looks brutal, Glen.
Do you think these would be strong enough for my winter wheels 'cos I really like them especially for their bling?  :wink:
http://www.performancealloys.com/wheel-details.aspx?ID=630
Title: Re: Wheel & Tyre weights!
Post by: Hurdy on 20 June 2011, 16:27
Strength is key, that is why I'd only buy from a maker that has a good reputation

The Team Dynamics Pro Race 1.2 is a strong wheel and was used in BTCC
The BBS wheels have always been strong
The OZ alloys also are very strong and the Alleggerita's are flowformed for extra strength.

Chinese plasticine alloys are brilliant at wasting your money. I tend to try and stick to the old saying - buy once, buy right :smiley: but even that doesn't always work as the Eibach dampers on the MKV were  :sick: :sick: :sick:
Title: Re: Wheel & Tyre weights!
Post by: mac7 on 20 June 2011, 18:26
1kg off the unsprung rotating mass is the equivalent of 5kg from the sprung static weight of the car.

That equates to 4.6kg a corner or 18.4kg for the car. Multiply this by 5 and the effect on the car is like removing 92kg from the sprung static weight. :cool:

I'm sceptical... where does this come from?
Title: Re: Wheel & Tyre weights!
Post by: am1w on 20 June 2011, 20:54
Hit two more massive potholes today. They are popping up (or down) everywhere. The rain has not helped. No damage. Will my luck last?  :rolleyes:
Title: Re: Wheel & Tyre weights!
Post by: Hurdy on 20 June 2011, 22:46
1kg off the unsprung rotating mass is the equivalent of 5kg from the sprung static weight of the car.

That equates to 4.6kg a corner or 18.4kg for the car. Multiply this by 5 and the effect on the car is like removing 92kg from the sprung static weight. :cool:

I'm sceptical... where does this come from?

I got it from here..........

http://www.360autodesign.co.uk/Alloy_wheel_packages/Carbon_Magnesium_780.aspx

They actually say 6 x  :shocked:
Title: Re: Wheel & Tyre weights!
Post by: mac7 on 21 June 2011, 19:11
Mmmmm carbon fibre and magnesium wheels  :cool:  £5, 138 for a set of 4  :shocked: