Rolling res vs tire weight

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BOOT
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Rolling res vs tire weight

Post by BOOT » Wed Apr 13, 2016 8:20 pm

If you could have less rolling resistance but the tire weighs more, would it be worth it?
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Re: Rolling res vs tire weight

Post by Greenlight » Thu Apr 14, 2016 11:03 pm

There is not an easy yes or no answer to your question.

1) How much is the rolling resistance reduced?
It normally takes about 2% of the vehicles weight to move (push) the car. So a 3000 lb. vehicle would take about 60 lb. of force to keep it rolling. Let's say you had a 24" diameter wheel (1 ft. radius). That means that it would take 60 lb. ft. of torque (imagine using a torque wrench on the center of your axle) to keep the car rolling (note that it may take more to get the car to start rolling). Your new low rolling resistance tire may reduce this value by 10%. So now it takes 54 lb. ft. of torque, a 6 lb. ft. improvement.

2) How much of an increase in weight and how much additional torque does it take to accelerate the wheel/tire assembly from let's say zero RPM to 1500 RPM at the finish line (7500 RPM engine w/ 5:1 rear axle ratio)?
It would take me too long to write the equations needed, so check out this web link and fill in your numbers into their example.
http://www.dummies.com/how-to/content/h ... ate-a.html
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Re: Rolling res vs tire weight

Post by BOOT » Fri Apr 15, 2016 12:01 am

Thx for the reply Greenlight, I totally agree not easy and many factors.
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Re: Rolling res vs tire weight

Post by joe 90 » Fri Apr 15, 2016 2:50 am

It depends a lot more on the tyre pressure.

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