Just like the title says. At the deepest points, what is the tire tread depth for new SO2s? I'll take it in hundredths of an inch or millimeters. Anyone know?

 

Sure Bill - the maximum tread depth on new OEM Bridgestone SO2 tires is 9/32" = 7.1 mm.

Note that there are several places on the tread surface that have much shallower grooves than that. I replace my tires when they've worn down to 3/32" = 2.4 mm.

 

Thanks Doc. I just bought a set of take-off SO2s that reportedly had less that 2,000 miles on them. They look good, but I was just wondering how they compare to brand new. Based on your info, I'd say the fronts are just like new and the rears are showing about 1/64th of wear. I wrapped them up in plastic garbage bags for next year when I'll need them.

 

you sure about that doc?

i measured my new S0-2's WAYYYY back in the day and got 7/32.

is this spec "printed" anywhere?? website maybe??

 

Pretty sure. I measured my new tires with a dial indicator and got the 7.1 mm value at several places around the circumference of the tire, and at several locations across the tread surface. I also noticed that at several other places, notably in the secondary grooves and on the wearbars in the primary grooves, the tread measured 5.0-6.0 mm. Also, if you measure too close to the edge of the tread, the tread depth decreases.

 

I just double-checked on The Tire Rack website and they quote 10/32" (= 7.9 mm)as the tread depth on both rear and front SO2 tires, so I must have compressed the rubber with my dial indicator a little bit.

 

sorry doc, i thought my gauge was in inches....it is, in fact, in MM as well.