

| Subject: | Re: Why new tires should go on the rear. |
| From: | Don Hanson |
| Date: | Sun, 12 Jul 2015 08:28:00 -0700 |
> > > > > > http://blog.allstate.com/new-tires-rear/?cid=CSY-PB-ZM-AB-outbrain_com:New-T > > ires-To-The-Rear > > > > The driver drove through the track with the new tires on the rear and let > > the front tires hydroplane. This is an easy recovery, just back off the > > gas. > > Not so fast (pun unintended).....In a rear-engined vehicle, catching a slide from the rear wheels isn't always that simple or easy...especially if the slide has gone unnoticed by the driver for too long, and "too long" isn't that long (a fraction of a second) in a rear-engined vehicle... .Consider that there is a big lump of mass (the whole motor) back there, beyond the rear tires. Once that mass begins swinging around, rotating the vehicle with the help of centrifugal force, letting off the gas AND steering into the slide doesn't work as well as it does with a front-engined vehicle....When you lift your foot, the vehicle decelerates, and some of the traction (grip to the road) that you already don't have enough of at the rear, that grip is transferred to the front tires (just like stomping on the brakes, but of course, we never do that during a slide, do we?)...Exactly what you DON'T need, that added traction at the front tires and the subtracted traction from the rear, as the vehicle rocks forward on it's suspension........ Steering into the skid IS the best hope of saving it from a spin....but letting off, dropping throttle, during a slide, that's usually when the driver has the experience he later describes something like...."Geeze, I thought I had it saved, but all of a sudden, it, like,....snapped around on me, and I hit the ditch backwards......" The older rear-engined Porsche race cars were notorious for this kinda handling...they took a lot of learning to make them go fast around a road-course. "Slow in-fast out" was their mantra (so that a slide never had the chance to start and decelerating while cornering was never called for). Those rear engined cars also came from the factory with much bigger rear tires to help control their tendency to oversteer..(rear end lets loose first) Of course, a total over-simplification. For those who are interested in learning how the vehicle behaves, you might want to find a safe venue and safely induce some of the situations..safe. safe.. and don't tip over your Vanagon... .I learned really a lot about my vehicles on a formal "skid-pad" at a race track...a great big paved area where one vehicle a time was allowed to circle around at what ever speed you wanted...experimenting with full throttle, brakes, steering, etc...I also learned a lot living and driving various vehicles in the mountains of the West on snow covered roads...some of the lessons were expensive... Me? I put new rubber onto my front wheels if everything else is equal...Not for traction but more to reduce the chances of an explosive tire deflation and the chances of dropping the vehicle onto the wheel rim during a dicey traffic or terrain situation... (disclaimer) YMMV and this is my internet opinion only... DHanson Then the driver hammered through the track with the new tires on the front, > > throwing the car into a spin. This was impossible to recover from. > > > > Reality is "normal driving" where your back tires break loose and you > steer > > into the slide & regain traction. > > > > No thanks - I'll continue mounting new tires on the front. >
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