Tire size = Brake failure?

crushnut · Mar 10th, 2005, 11:23 AM

I was using a tire size calculator where you compare the specs of the original tire to the tire size you want to go up too, and it said you don't want to go more than 3% larger or you could risk brake failure, is this true? Because 3% isn't very much of an increase.

Thanks

**88pathoffroad** · Mar 10th, 2005, 11:36 AM

Not as far as I know. There are thousands of trucks running around with stock brakes and 38's or larger on them.

96R50 · Mar 10th, 2005, 12:06 PM

The term failure is a bit misleading. Larger tires like 38s in place of 28s will put the brakes at mechanical disadvantage. 3% larger sounds a bit conservative, but that is because the author of the article doesn’t want any kind of liability issues. I run 31s in place of my stock 28s, 10% larger than stock, and I’m happy with my braking performance.

Keep in mind that if you go wider and larger you’re adding mass to the longer lever arm.

aaronford · Mar 11th, 2005, 06:15 AM

I put 235/60/15s where 195/75/14s were and I did lose some braking and acceleration but I gained in lateral acceleration! I can also throw it into a perfect four wheel drift, tightening with the throttle and loosening with the wheel, something the 195s never could do. All they knew how to do was understeer.

crushnut · Mar 11th, 2005, 12:59 PM

Quote:

Originally Posted by aaronford

I put 235/60/15s where 195/75/14s were and I did lose some braking and acceleration but I gained in lateral acceleration! I can also throw it into a perfect four wheel drift, tightening with the throttle and loosening with the wheel, something the 195s never could do. All they knew how to do was understeer.

According to the tire size calculator that is only a 2.27% difference in diameter. And a speedometer difference of 2.308% too slow.

Here is the link if your interested: http://www.1010tires.com/TireSizeCal...?action=submit

aaronford · Mar 12th, 2005, 12:09 PM

Thanks! I suspect the weight difference in the tire and wheel combos plays a big role as well. The suspension seems like it has a hard time keeping the heavier wheel and tire in control when to going gets bumpy.