Tire speak

[Rich Fredette]

72 JP175 restore - Need to replace dry rot units. Stock specs at 3:00x21 front and 4:00x18 rear, mine a 4:50 rear on it. What is the metric equivalent to replace stock tire sizes, and if any opinions on medium $$ mfg. recommendations. - Thx.

[Dale Sonnenschein]

Tire sizes vary from one tire manufacturer to another. Even with the same numeric number you can put them side by side and have two different size tires. I think a 100/90 or a 100/100 would be about equivalent to the 400. Here is a chart from Maxxis.

Front Tires
Metric   Alpha   Inch
60/100   90/80   2.50/2.75
70/100   90/90   2.75/3.00
80/100   100/80   3.00/3.25
Rear Tires
Metric   Alpha   Inch
80/100   80/90   2.50/3.60
90/100   110/90   3.60/4.10
100/100   120/80   4.00/4.10
110/100   130/80   4.00/4.50
120/100   140/80   5.00/5.10





73 Jackpiner
73 Husky 360 WR/RT
76 Husky WR360
78 husky cr250
82 husky wr430
10 ktm 250xc
02 bmw r1150r

[Rich Fredette]

Thank you Dale. Yes, the Metric vs. Alpha threw me off when I first started looking, so I thought best to go to the POG. I'll check out Maxxis site.

[brian kirby]

Most modern tires are too big for a vintage 125 or 175. The best tire available for that bike is the Pirelli MT16 110/100-18, and the Pirelli MT16 front is also excellent, and they look correct.

Brian