Playing with an idea of Dinan wheels. Thay seem to be the lightest on the market. 17-18 lb compared to 26 for stock is a huge improvement. Combined with European floating rotors - will give a tremendous reduction in unsprung weight.
Conserns: Forged aluminum - how strong is it. Are these wheels stronger then OEM. Boston "war zone" roads are not kind to any rims... But with better handling I'll autocross between putholes better
I know Mark had these wheels for a while, is 285 on the rear and 275 front good way to go or is it easier to stick with 275 rear, 265 front without rolling more fenders and putting spacers and possibly saving some weight?
BostonRocket considered getting them, but after talking to the Dinan guy at BMW Gallery, he was told that some other guy got the rims, but bent 3 of them in the same day on Boston roads! Well, I personally think it's the way you drive, and if you're careful, the chances of bending them aren't that high.. but you would never know... I personally would go for 19" rims if I were to change anything...
__________________ US Spec 2001 E39 M5 - LHD AC Schnitzer
DFC suspension, anti-sway bars, pedals
front splitters, rear wing w/ carbon fiber
i like mine a lot now that i've gotten used to the looks
they're strong and light and expensive -- if the roads are that bad you may want to consider some of the light weight 2 and 3 piece wheels -- there are some that are only a pound heavier than the Dinans and if you bend it you don't have to replace the whole thing
i've got 275/285 on 9/9.5 per Dinan's recommendation, rolling the rear fender lip is not a big deal (some cars need it even with 275's) and i don't notice the steering limiter; but with the experience of people on the board fitting 275's on 9.5 in front i'd put 275's on 9.5's all round with the 5mm spacer on the front in order to rotate tires front/rear
if you're worried about potholes, 19's are not the way to go
The Dinan wheels are cool, I like mine. Light and strong. I didn't like their looks at first but after seeing SteveR's wheels a couple of times I was clearly jealous of his wheels so I got them. I had mine recoated so they are all one finish, very close to the M5 OEM finish. The Dinans come with the outter part of the rim polished and the spokes with a matt finish. I also have BMW Roundels on the centers rather than the Dinan logos, also no spacers needed. I could not find any other one piece wheel I liked better. My preference would be a clean, light, strong, one piece, radially symetrical, 10 spoke wheel with a lot of air in between the spokes and a powdercoat finish that looks like the OEM color. 18" is the only size I would want, 9"or 9 1/2" in front and 9 1/2" or 10" in the rear. The Dinans, 9'' front and 9 1/2" rear, came pretty close to what I wanted.
Nothing bent yet. (knock knock) That includes a trip through the Boston area as well, (Oktoberfest) and fighting the city's latest project "brick sidewalks" down here. Just have to pay attention to where your driving.
Now I have bent the rims on our X5. (stock with chrome finish) Not sure yet where we managed to do that.
__________________ Mark 2003 X5 4.4 Sport 2002 Mini Cooper S
I can't imagine that saving about 35-40lbs. total in wheel weight would make that much difference on this car. So, there must be something to this "unsprung weight". Could someone explain why "unsprung" weight is any different than "sprung" weight when it comes to performance?
Thanks,
Chris
Last edited by Dallas Spikes; 27th November 2001 at 03:34.
The whole point of the suspension in a car is to keep the tire patch firmly on the pavement. Doing this as the road changes, the car weight shifts around, etc., is close to black magic to me. I don't know how they do it, but you can feel the difference when they do it right. Imagine what would happen as a tire rolled over a bump in the road if the suspension wasn't there. The tire would have to absorb all the energy of the bump and would likely leave the pavement and you would have no traction!
Unfortunately, the suspension can't do anything to correct the influence of unsprung weight. This must fall on the tire itself. Using my example from above, as the tire goes up the front slope of the bump, the sidewalls must compress to absorb the energy of the unsprung weight (the suspension is doing to this for the rest of the car weight). And as the tire rolls down the backside of the bump, the sidewall must expand to keep the contact patch in contact with the road until the suspension can push the tire back down. The more weight that is not absorbed by the springs (thus, unsprung weight), the more work the sidewall has to do and vice-versa.
Another aspect of this that is specific to the wheel weight is rotational inertia. The heavier the wheel the harder it is to get it spinning. This will impact both your acceleration and braking.
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