smart rear wheel camber

[eqwalker]

I sure would! Why design a suspension so that you must use so much negative camber to start with? Tires are not made to ride more on one side than the other. Otherwise, all cars would have "noticeable" negative camber. I've had several Corvettes and noticeable negative camber was a sign of worn suspension and needed repair (which I have had to have done on one of mine). Yes, I have seen it on Porsche's (I've had two of those) and had them worked on as well. "Noticeable" negative camber was excessive and was found to be out of alignment on the vehicles that I had to have corrected. Why would you want to design a rear suspension that you have to have so much negative camber? I don't mind a little, and like I said, I understand the reason for it, but not to the extent that the smart has that results in uneven tire wear. If I was going to spend time at the track and race them a lot, then maybe so. But not for everyday driving.

[Old smart]

If the smart had a "true" De Dion rear suspension (the tube located laterally by a vertically-moving watts linkage) the rear wheels would always be perpendicular (0 camber), and regardless of body lean. One of the multiple benefits of a true De Dion.

[a2jack]

Padawan. Yes front was also in spec.

Smart sent it out to a disinterested, third party shop with a first class alignment set up. (Toyota of Waterford, Michigan). A2Jack

[Docthrock]

I wondered about the "negative camber" way late last Spring. Went to Indy and looked at about 20 smarts sitting on the lot. They're all that way. Dunno why. Happy to report that after 12500 miles my (especially rear) tires all appear to be wearing evenly... which doesn't make sense. But evedently they ARE engineered that way correctly.

[eqwalker]

Originally Posted by Old smart

If the smart had a "true" De Dion rear suspension (the tube located laterally by a vertically-moving watts linkage) the rear wheels would always be perpendicular (0 camber), and regardless of body lean. One of the multiple benefits of a true De Dion.

Agreed. Indeed true.

[GHammerly]

2 deg. of negative camber will not wear the tires exesively as long as the toe is close to zero. Many contemporary cars have about two deg. negative camber at the rear suspension, my wife's Acura TSX for example.
You wonder why? Negative camber helps the tire have more lateral grip or cornering grip, give the rear more grip and it will keep the rear of the car where it belongs, smart also equiped the car with skinny front tires and wider rears to add even more stability. The smart is a short, tall, and narrow car, this is one of the features built in to the car to keep you safe.

[Old smart]

When I was a funny-looking high school freshman (1959-1960) we were given a writing assignment in General Science class – something that involved some degree of “technical research.” I was by then way into being an “aficcion e cognizento” of international motor sports, and chose the topic of tire grip. I wrote to everyone I favored – Pirelli, Dunlop, Avon, Michelin, etc. (I wasn’t into Goodyear or Firestone). I actually got a lot of useable stuff back, including a translated copy of a treatise written by racer/engineer Piero Taruffi, PhD. It concerned the lateral deflection of the then new Michelin X (radial) tires. At that point, bias-ply tires were the norm. Taruffi wrote that even with lateral deflection (during hard cornering), the radial tread remained parallel to the road surface if suspension lean wasn't a factor (i.e. De Dion or solid axle), due to the sidewall construction. The bias-ply tires would “roll-off” to some extent.

Thus, in reference to a true De Dion rear suspension, I am convinced that the smart’s mild negative camber is to compensate for body roll amd high-weight transfer.

N.B. Yah, I’m probably still funny-looking.

[Godfather]

One would imagine that all the various forms of motor racing chassis setups that feature camber like ours must know something. I'm absolutely sure if I never used the brakes and drove like my hair was on fire I could wear out tires with the best. But why would I?

[fortow]

From my experience with the smart so far, the 2 degrees of negative camber on the rears may actually help to keep tire wear even - maybe that's also a function of how the car is driven though. My front tires show more wear on the inside edges but the rears are wearing evenly across the tread. Maybe the fronts are wearing like that due to no toe-in or some toe-out, I need to check the alignment to determine that. Hopefully no suspension components are bent.

[LittoDeviL]

I have 19,600 miles on the car now and I drive it.. .. EXTREMELY hard..... I have to say tire wear is actually ... fairly even not bad at all.

Cheers!
Larry