Mu/85/16 vs. MU/90/16

[Old Coot]

I know the "90" has a little taller sidewall. Is it enough to be noticeable on a "06" RK cop bike? I ride solo 99% of the time. I'm not exactly sure why I didn't stay with the "85" when I ordered new tires. I have 402's on it now, I ordered E3's. MT/90/16 frt.- MU/90/16 rear. I looked on a tire calculator, it didn't look much taller. It only throws the speedo off by a couple of mph. at 55 mph. I've been a little stressed about it after I thought about it awhile. If it's going to be a problem, I need to start making other arrangements. Any help will be greatly appreciated.

[Dave63]

Originally Posted by Old Coot

I ordered E3's. MT/90/16 frt.- MU/90/16 rear.

I believe it's an MU8516.


MT9016 is a 130mm tire

MU8516 is a 140mm tire

You'll get about 30% more mileage out of an MU then an MT.

Lets do the math:

MT9016 = 130/90-16 (metric version)

130mm / 90% sidewall aspect x 16" diameter rim.

130mm/117mm x 406.4mm

117mm sidewall + 406.4mm + 117mm = 640.4 Total height, or 25.21" tall
___________

MU8516 = 140/85-16

140mm / 85% sidewall aspect x 16" diameter rim.

140mm / 119mm x 640.4mm

119mm + 406.4mm + 119mm = 878.4mm or 644.4mm or 25.37" total height.

[Old Coot]

I have a 85 on it now but I ordered a 90 for some reason. Will it be noticeably taller, in a bad way? I don't think room will be an issue.

[Dave63]

A tad taller....

Your current tire (MU8516) is: 25.3" tall.

140/90x16 =

140mm/90% sidewall aspect x 16 = 126mm

126mm + 406.4 + 126mm = 658.4mm or 25.92"

So....that number is total height, that would affect final drive, but since you're already reading a tad lower than actual speed, the added .55" or half inch. A half inch will only raise rear ride height 1/4", and you'll see nothing different on your speed or mileage that's going to be even noticable.

[Old Coot]

Thanks Dave, You are the man! I could never have been able to come up with those formulas and done the math. I feel a lot better now. I've done some more checking and I don't think They make an E3 in a "85. I read some where that the E3 MU/90 is the recommended replacement for the 402 MU/85. Now I can hardly wait for them to come in and get those bad boys mounted. Once again, Thanks Dave. P.S. I'm tired of the labor pains. I'm ready for the baby!