2141smh@aluxe.UUCP (henning) (10/24/84)
**** **** From the keys of Steve Henning, AT&T Bell Labs, Reading, PA aluxe!2141smh > Since the traction on a light rear wheel drive car isn't that great, I'd > like to put 205/60SR14 on my car, where 185/70SR14 currently reside. > > HOW DO I DETERMINE WHAT TIRES ARE BEST FOR MY CAR? I'd like to get > traction in the rain and snow too. (I live in the N.Y. metro. area.) Oversized tires REDUCE traction since the lower pressure on the road prevents the tire from conforming to the roughness of the road and 'gripping' the surface. A friend with a Porsche got over sized tires and found his formerly nimble car was slidding all over the road. He quickly got rid of them and lost a bundle, before he lost his life. Sears currently is having a sale on 50,000 mile Michelin radials. They have an 'all-weather' tire which should give you the best traction you can get in the rear.
haapanen@watdcsu.UUCP (Tom Haapanen [DCS]) (10/25/84)
<.> >> Since the traction on a light rear wheel drive car isn't that great, I'd >> like to put 205/60SR14 on my car, where 185/70SR14 currently reside. >> >> HOW DO I DETERMINE WHAT TIRES ARE BEST FOR MY CAR? I'd like to get >> traction in the rain and snow too. (I live in the N.Y. metro. area.) > > Oversized tires REDUCE traction since the lower pressure on the road > prevents the tire from conforming to the roughness of the road > and 'gripping' the surface. A friend with a Porsche got over sized > tires and found his formerly nimble car was slidding all over the > road. He quickly got rid of them and lost a bundle, before he lost > his life. It is true that too wide a tire will reduce traction, especially in the ice and snow. However, what you might want is a better tire compound and/or tread pattern. If you now have 185/70SR14, you migh check into 185/70HR14s or 185/70VR14s. HR and VR rated tires usually have better quality compounds and treads. Going to a 205/60 will reduce your traction in the snow, although a good tread design (Pirelli P6 or Comp T/A, for example) will improve wet traction considerably. For normal, use, I'd stick to 185/70s. Check out some of the following brands (most of them should have the right size): - Pirelli CN36 - B.F.Goodrich T/A 70H - B.F.Goodrich T/A 70V - Fulda Y2000 - Goodyear NCT Depending on your suspension, you might want to go for a relatively round-shouldered tire, such as the CN36. Tom Haapanen University of Waterloo (519) 744-2468 allegra \ clyde \ \ decvax ---- watmath --- watdcsu --- haapanen ihnp4 / / linus / The opinions herein are not those of my employers, of the University of Waterloo, and probably not of anybody else either.
mark@gatech.UUCP (Mark Johnson) (10/29/84)
> **** **** > From the keys of Steve Henning, AT&T Bell Labs, Reading, PA aluxe!2141smh > > > Since the traction on a light rear wheel drive car isn't that great, I'd > > like to put 205/60SR14 on my car, where 185/70SR14 currently reside. > > > > HOW DO I DETERMINE WHAT TIRES ARE BEST FOR MY CAR? I'd like to get > > traction in the rain and snow too. (I live in the N.Y. metro. area.) > > Oversized tires REDUCE traction since the lower pressure on the road > prevents the tire from conforming to the roughness of the road > and 'gripping' the surface. A friend with a Porsche got over sized > tires and found his formerly nimble car was slidding all over the > road. He quickly got rid of them and lost a bundle, before he lost > his life. I'm sorry but I disagree. If the inflation pressures are equal then the size of the contact patch will be the same regardless of tire width! -- Mark Johnson (404) 894-2746 (404) 894-3152 CSNet: Mark @ GATech ARPA: Mark%GATech.CSNet @ CSNet-Relay.ARPA uucp: ...!{akgua,allegra,amd,hplabs,ihnp4,masscomp,ut-ngp}!gatech!mark
2141smh@aluxe.UUCP (henning) (10/31/84)
> > Oversized tires REDUCE traction since the lower pressure on the road > > prevents the tire from conforming to the roughness of the road > > and 'gripping' the surface. > I'm sorry but I disagree. If the inflation pressures are equal then the > size of the contact patch will be the same regardless of tire width! **** **** From the keys of Steve Henning, AT&T Bell Labs, Reading, PA aluxe!2141smh I would agree if we were talking about innertubes or some soft compliant tire, but the radials that are put on the road today are claimed to have flat footprints and provide more traction. That is due to the rigidity of the steel belts. If the tread width was too wide, the tire would act like a snow ski. Try using your shoe as a crosscountry ski and you will find that area affects traction. If you don't want the leg on a tripod to slip you put a sharp point on it rather than increase its footprint.
marcus@pyuxt.UUCP (M. G. Hand) (11/02/84)
>> > Oversized tires REDUCE traction since the lower pressure on the road >> > prevents the tire from conforming to the roughness of the road >> > and 'gripping' the surface. >> I'm sorry but I disagree. If the inflation pressures are equal then the >> size of the contact patch will be the same regardless of tire width! > >>From the keys of Steve Henning, AT&T Bell Labs, Reading, PA aluxe!2141smh > >I would agree if we were talking about innertubes or some soft >compliant tire, but the radials that are put on the road today >are claimed to have flat footprints and provide more traction. >That is due to the rigidity of the steel belts. If the tread width was >too wide, the tire would act like a snow ski. Try using your shoe >as a crosscountry ski and you will find that area affects traction. >If you don't want the leg on a tripod to slip you put a sharp >point on it rather than increase its footprint. So you'd have us all driving around on studded ice tires? >:-) I'll stick to my soft wide radials for most of the year, thanks. marcus hand (pyuxt!marcus)
mark@gatech.UUCP (Mark Johnson) (11/06/84)
> > > Oversized tires REDUCE traction since the lower pressure on the road > > > prevents the tire from conforming to the roughness of the road > > > and 'gripping' the surface. > > I'm sorry but I disagree. If the inflation pressures are equal then the > > size of the contact patch will be the same regardless of tire width! > > > **** **** > From the keys of Steve Henning, AT&T Bell Labs, Reading, PA aluxe!2141smh > > I would agree if we were talking about innertubes or some soft > compliant tire, but the radials that are put on the road today > are claimed to have flat footprints and provide more traction. > That is due to the rigidity of the steel belts. If the tread width was > too wide, the tire would act like a snow ski. Try using your shoe > as a crosscountry ski and you will find that area affects traction. > If you don't want the leg on a tripod to slip you put a sharp > point on it rather than increase its footprint. You missed the point. Inflation pressure is by far the biggest factor in determining contact patch size. The shape of the contact patch will vary, but the size will not. One reason modern radial tires are "better" than bias-ply tires is they are MORE COMPLIANT. -- Mark Johnson (404) 894-2746 (404) 894-3152 CSNet: Mark @ GATech ARPA: Mark%GATech.CSNet @ CSNet-Relay.ARPA uucp: ...!{akgua,allegra,amd,hplabs,ihnp4,masscomp,ut-ngp}!gatech!mark
ix1037@sdcc6.UUCP (Christopher Latham) (11/09/84)
> You missed the point. Inflation pressure is by far the biggest factor in > determining contact patch size. The shape of the contact patch will vary, but > the size will not. One reason modern radial tires are "better" than bias-ply > tires is they are MORE COMPLIANT. > -- The sidewalls of a radial are more compliant than those of a bias ply tire but the belts in the tread area are supposed to cause this area to be stiffer and to help it remain flatter than on the bias ply tires. Christopher Latham U.C.San Diego Dept. of Applied Mechanics and Engineering Sciences ..sdcsvax!sdcc6!ix1037