[kaishang]

Ahh, it seems my 284-style 17" wheels weigh 10.36kg

[ALF_E90]

Large light wheels with spokes will be an inherently weak design - spoked wheels are basically a very weak shape and the manufacturers work miracles to make them as strong as they are. I always liked my alfa telephone-dial wheels as they looked lovely and are an inherently strong design.

The style 162 18's I'll probably sell are reasonably light (12kg ish) and look like a very strong design. One of my 17" style 185 winter wheels has a big flat spot on the inside edge, which is how it was when I got it (as part of a well-used set from Ebay, though the buckle was not declared so I'm trying to get the seller to find me another single one, cheap). Whether that is related to it being one of the lighter OEM wheel designs or not, who knows, I'm hoping the set I just bought for summer use is straighter

With potholes as bad as they are there seems to be a lot of wheel and tyre damage out there, and unfortunately (since they cost a lot more) runflat tyres seem to suffer more than most.

[F31-340i]

Originally Posted by ALF_E90

Large light wheels with spokes will be an inherently weak design - spoked wheels are basically a very weak shape and the manufacturers work miracles to make them as strong as they are. I always liked my alfa telephone-dial wheels as they looked lovely and are an inherently strong design.

The style 162 18's I'll probably sell are reasonably light (12kg ish) and look like a very strong design. One of my 17" style 185 winter wheels has a big flat spot on the inside edge, which is how it was when I got it (as part of a well-used set from Ebay, though the buckle was not declared so I'm trying to get the seller to find me another single one, cheap). Whether that is related to it being one of the lighter OEM wheel designs or not, who knows, I'm hoping the set I just bought for summer use is straighter

With potholes as bad as they are there seems to be a lot of wheel and tyre damage out there, and unfortunately (since they cost a lot more) runflat tyres seem to suffer more than most.

Teledials came up the other day in here...

http://www.e90post.com/forums/showthread.php?t=475561

I think the weakness on the 19" 225s wheel is mainly on the inner rim - it is a wide wheel that is obviously thin and a totally flat profile toward the inner rim edge - not well suited to taking a bashing on hard low profile RFTs.

[ALF_E90]

Originally Posted by ///ajd

Teledials came up the other day in here...

http://www.e90post.com/forums/showthread.php?t=475561

I think the weakness on the 19" 225s wheel is mainly on the inner rim - it is a wide wheel that is obviously thin and a totally flat profile toward the inner rim edge - not well suited to taking a bashing on hard low profile RFTs.

Thanks, just posted a few pics of my beloved 156GTA SW on there, including a close-up of one of the teledials that is one of my favourite of my car photos...

[HighlandPete]

I'm not sure the Felgen rim weights are totally accurate. I notice for the 225M they give the same weight, for both 8" & 9" widths. Maybe, but does seem wrong for the extra width. Most staggered sets show at lesast 0.5kg increase on the wider rim.

Still can't fathom my 160 rim weight, Felgen quote 12kgs, but I know the Bridgestone RFT is about 12.7kgs, the total weight when weighed last month was 23.2kgs, so the rim can't be 12kgs. I say it's about 10.5kgs which seems more in keeping with the other 17" rims.

No immediate plans to remove a wheel to prove the weight, but I'm tempted.

For 335diesel, I see the CSC3 is about 9.5kgs for a 225/45 R17 94Y XL. On a 160 rim it should be something like 20kgs. My winter tyre should be about 20.2kgs on the 160.

I'll weigh a 8" x 17" 161 with the Falken 452 on, tomorrow, and see what weight that is.

HighlandPete

[Em135eye]

Good work Pete! I noticed quite a few weight anomalies too so also not convinced by the felgen sites figures.

[ALF_E90]

We could do some weights of our own on here. I have 18" 162 fronts and rears in the garage with runflats on, happy to weigh them at the weekend with the scales I use for my mountain bikes!

[Em135eye]

ALF - weird to think that just a tyre (or rim) weighs more than many MTBs!

[HighlandPete]

Even more curious about the weight of the 160 with a winter tyre fitted. I've weighed the 161's, with Falken 452's.

8" x 17" with 225/45 94Y XL = 24.2kgs
8.5" x 17" with 255/40 94Y = 26.1kgs

I was surprised, so double checked with a baggage scale, same results within 0.1kg.

I found the weight I recorded for the 161's, with Goodyear F1 GS-D3's fiited, 23.7kg & 24.75kg. I've read the Falken's are a heavy tyre, this proves it.

So the 160 with Bridgestone RFT is lighter than the same size 161 with a Falken fitted. 23.2kg vs. 24.2kg.

I must get a 160 off the car, as soon as the weather is better and see where we are with a non RFT fitted.

HighlandPete

[Em135eye]

Pete - I will do the same when I get the chance. Then it's even more "scientific!"

[F31-340i]

Originally Posted by HighlandPete

Even more curious about the weight of the 160 with a winter tyre fitted. I've weighed the 161's, with Falken 452's.

8" x 17" with 225/45 94Y XL = 24.2kgs
8.5" x 17" with 255/40 94Y = 26.1kgs

I was surprised, so double checked with a baggage scale, same results within 0.1kg.

I found the weight I recorded for the 161's, with Goodyear F1 GS-D3's fiited, 23.7kg & 24.75kg. I've read the Falken's are a heavy tyre, this proves it.

So the 160 with Bridgestone RFT is lighter than the same size 161 with a Falken fitted. 23.2kg vs. 24.2kg.

I must get a 160 off the car, as soon as the weather is better and see where we are with a non RFT fitted.

HighlandPete

Crikey - so a 265/30R19 Falken 452 on a 225M 19" wheel weighs 1.4Kg less than a 255/40R17 Falken 452 on a 17" 161.

Either that or my digital bathroom scales* are under-reading - a bit worrying given what else I weigh on them

Felgen Katalog has a 161 weighing only 9.7Kg/10.2Kg front rear so either the 17" wheel weights are wrong or the Falken is really very heavy.

This appears to go against conventional wisdom on larger wheels being heavier.










* they're a nice German set and pretty accurate I think - just checked with some sugar and other known kitchen items and if anything they're slightly overreading (i.e. the 19" 225M wheel & tyre is lighter than 24.7Kg).

[Em135eye]

Just found this website with some tyre weights - not sure how accurate it is?

http://www.tirerack.com/tires/tires....a+RE050A+I+RFT - hit the "specs" tab at the bottom.

It has Conti SC3s non RFT 225/45 17" XLs at 20lbs or 9.1kgs.

The 255/35 19" version is 25lbs or 11.3kgs.

A 225/45 17" Bridgestone RFT RE050A (BM specific) is 26lbs or 11.8kgs- a LOT heavier!
A 255/35 19" is 27lbs (12.2kgs)

Unfortunately they don't have Falkens!

If the tyre weights are accurate, using Pete's 160 with RFT reading that means a 160 rim weighs 11.4kgs, not 12kgs.

It means my 160s with CSC3 non RFTs are 20.5kgs each. Pretty darn light really.

Also shows that non RFTs are pretty light compared to RFTs.

And using the weights on Felgen (yes that's a bit naughty I know as I've just dissed their figures!) I get a 19" 225M and a 255/35 RFT tyre weighing in at 12.63kgs + 12.2kgs = 24.82kgs or 23.93 with a non RFT CSC3.

So 19s inch 225M rears with RFTs weigh in at 4.32kgs (or almost 20%) of unsprung and very fast moving weight more than my "non sporty" 160s with non RFTs...

Now I wonder how much more M sport kit weighs than SE kit...? Bigger seats, more plastic, etc.

We already have almost 20kgs weight difference just in wheels and tyres...

[I6Touring]

Originally Posted by 335diesel

A 225/45 17" Bridgestone RFT RE050A (BM specific) is 26lbs or 11.8kgs- a LOT heavier!

I just tried to weigh my 17x8 Style 158 wheels fitted with those tyres using a 22kg max spring balance, but it went off the scale by what looks like at least 2kg. The felgen katalog says these wheels should weight 9.38kg so something's wrong here! Hopefully its just my (cheap) spring balance as I had been enjoying the thought that my wheels were relatively light.

I did notice the smaller wheels and non-RFT winter tyres I fitted in October were lighter, but didn't weigh them at the time.

[HighlandPete]

The more I investigate, the more I see the Felgen quoted weights, as way out on some specs'.

My RFT was the Bridgestone Potenza RE050A II, the nearest weight I find (Tirerack, 91V OE BMW) is 28lbs, 12.7kgs, so my 23.2kgs total, makes the 160 rim 10.5kgs. (Felgen 12.0kgs).

I've just got to get a 160 off the car and confirm the weight, it should be from the calcs': Rim 10.5kgs + Vredestein Wintrac 9.7kgs = 20.2kgs.

From Falken data sheets, the tyres I've fitted are:

225/45 R17; 26lbs, 11.8kgs. (Same spec' CSC3 is 9.5kgs), so the Falken is a heavy tyre. Michelin PS2 in similar spec' (91Y) is 10.4kgs.
255/40 R17; 25lbs, 11.3kgs. (Lighter than the 225/45 front tyre).

My total weights as posted in an earlier post, mean my rims are:

161 style, 8" x 17", Gross 24.2 - 11.8 = 12.4kgs. (Felgen 9.7kgs)
161 style, 8.5" x 17", Gross 26.1 - 11.3 = 14.8kgs. (Felgen 10.2kgs)

My, that is a heavy rim for an 8.5" x 17". 14.8kgs????

BTW, the Falken 452 265/30 R19 93Y XL is 11.8kgs. Same weight as the 225/45 R17 94Y.

HighlandPete

[F31-340i]

Originally Posted by balernoStu

I just tried to weigh my 17x8 Style 158 wheels fitted with those tyres using a 22kg max spring balance, but it went off the scale by what looks like at least 2kg. The felgen katalog says these wheels should weight 9.38kg so something's wrong here! Hopefully its just my (cheap) spring balance as I had been enjoying the thought that my wheels were relatively light.

I did notice the smaller wheels and non-RFT winter tyres I fitted in October were lighter, but didn't weigh them at the time.

Seems like all these wheels may weigh approximately the same, give or take.

I'd thought that the 158 was one of the lighter wheels - but its seems not.

The 160 style is shown on Felgen as a full 2.6Kg heavier than a 158, so your wheels could be the heaviest of all Matt - time to get the bathroom scales out!

There is the possibility of course that BMW have deliberately engineered & specified their OEM wheels of different sizes to have basically the same (unsprung) weight. They could certainly require their supplier to do this.

[F31-340i]

Originally Posted by HighlandPete

BTW, the Falken 452 265/30 R19 93Y XL is 11.8kgs.

HighlandPete

That would make my rear 225M 19" 9J wheel 12.9Kg.

Might go a weigh a front. We should all have better things to do

BTW the front 7J forged turbo Fuchs wheel on my 911 is only 8.1Kg, apparently.

[HighlandPete]

Originally Posted by ///ajd

Seems like all these wheels may weigh approximately the same, give or take.

There is the possibility of course that BMW have deliberately engineered & specified their OEM wheels of different sizes to have basically the same (unsprung) weight. They could certainly require their supplier to do this.

I think I weighed the 161 rims when I first got them, can't find any reference, although I've the weight with the original tyres I fitted, as I wanted the comparison to the RFT wheels. Was surprised at the time that the 161 front + Goodyear F1 GS-D3, was 0.5kg heavier than the 160 rim + RFT.

But if my 14.8kgs calculated rim weight is correct, then a RFT fitted (RE050A II 255/40 R17 OE BMW @ 13.6kgs), will make a total rear wheel weight of 28.4kgs... that throws the idea of BMW aiming at similar unsprung weights. That is a crazy weight for a 8.5" x 17" wheel.

I'm going to check it again tomorrow, now that I've sourced the weight for the tyre from Falken's own data.

HighlandPete

[Em135eye]

TBH ajd, the more I look at the Felgen weights, the more I see very dodgy readings. Pete has estimated just over 10kgs for the 160s. Add a mere 9ish kgs for the tyres and you have a very light set up. Anyway, the only accurate measurements will be our own I reckon but that tyre website is quite interesting.

[HighlandPete]

Problem with Tirerack's 'tires', often they are US spec's and can't be accurately cross referenced for the UK. But they do give a good spead of info' and tyre tech'. I've used the site for several years and communicated with their guys as well, a very good outfit.

HighlandPete

[Em135eye]

Pete - it's probably not a bad guide and I've checked loads of their figures - most seem "sensible" unlike Felgen's random wheel weights.

Anyone else think weights have got a bit silly on most "performance" cars? The lightest of the E9* group, the coupe, still weighs well over 1600kgs even with a dinky engine. I know the 3 series is quite a big car but that's still lardy. And no one seems to think twice about ticking every option box and adding more weight (yes I know our sunroof is a heavy option too!).

Would be great if another CSL type BM came out. Slightly affordable unlike the M3 GTR but properly lightened - sub 1400kgs would be a realistic target.

A 911 is around 1400kgs with 4WD and a 6 pot motor - I'm sure it could be done with a 3 series.

[doughboy]

Originally Posted by 335diesel

Would be great if another CSL type BM came out. Slightly affordable unlike the M3 GTR but properly lightened - sub 1400kgs would be a realistic target.

A 911 is around 1400kgs with 4WD and a 6 pot motor - I'm sure it could be done with a 3 series.

Fat chance when the new 1M coupe weighs in at 1590kg!!

A 911 is also a very small car compared to a 3er. (and costs aload more!)

It would be nice though....

[Em135eye]

Weird that BM spend so much on R&D for "clean" engines then stick them in cars that weigh more than the moon.

That 1M weight is mildly insane.