Date: 2 May 2007 01:00:15 -0700 From: targa <tmuehlhoffnospaml.com> Subject: Re: Classic 900 - aluminum or steel/best tires for sport driving
On Apr 28, 8:03 pm, robanzello...nospamlemail.com wrote: > Most of the used stuff I'm looking at is Alu 15"x6" with 205/60. This > profile is plenty tall to deal with the smooth roads here (there ain't > no Major Deagan Expressway in Deutschland!). The 185/65's I have now > are a bit squirrelly up in the 100mph+ range. you're not allowed to drive 205/60 on a C900 in Germany. Even for the 205/55 you'll need a special allowance from SAAB, unless you have MY87 (I believe). Addtionally you'll need distance blocks for the springs in the back. If you want to avoid this, go for 195/60 and buy "sporty ones" like Yokohamas or Bridgestone Potenza series. > Conceptually I figure that aluminum rims not only allow faster > accelleration and braking, as since being lighter, there is less > rotational inertia, but also, a lighter wheel can move up and down > faster, allowing the suspension to react faster to bumps and dips. As Why do you think so ? Aluminium needs lots of more volume of material in order to gain the same stability as steel. Unless you build your rims from magnesium you won't gain any advantage in weight. Acceleration is more dependant on the diameter of the overall wheel, which you're not allowed to change and braking is more dependant on the tyre (width, rubber type). The rotational inertia is maybe not less, but in most cases better dirtributed in steel rims. (Saab often has this 3-spokes as aluminium). When it comes to suspension the main factor are the shocks... not the rims. > I said, the effect probably depends on a lot of factors. I haven't > really noticed it with this car, but I'm probably gonna do it anyway > to get a bit wider, and also to indulge myself a little. I work hard! Some people think that the c900 doesn't run very well on 205/55 on 6Jx15 rims, they prefer either the 195/60 or 195/50 on 16" rims. I'll mount my 205/55s next week anyway and try out. /T.
