Self-Tapping Carbide Tire Studs #4720

After Action Report

Tires: Brand New Pirelli MT 60
120/70-17 Front, 160/60-17 Rear
(Super Motard knobbies, about as knobby as you can get for matching tires on 17" rims)

Studs: #4706 Low Profile A

About 70 studs in the rear tire and 55 or 60 in the front tire.

Result: Good grip on ice and snow, a bit of vibration on asphalt, and 18 punctures in 250 miles (three cheers for Stop-N-Go tire plug kits and the Green Slime tire pump held up very nicely). Green slime does not help, since the studs wiggle a little as they hit the ground and the slime works its way out (I have a green racing stripe on the underside of the bike).

For modern radial tires in street bike sizes, the #4706 is just too long, and they continue to work a little deeper as you go down the road (rubber flexing and the like). For street bike sizes, I would try using the studs made for scooters. I likely would have been better off with #4720, though I am sure I would have thrown some of them, as the #4706 studs were slowly working out in some places. Throwing studs is still safer than multiple punctures at highway speeds.

They are easy to install, but I would only recommend putting them in knobbies. If you have tires that have more tread depth than the stud length, you should be okay, but that would be very hard to find with street bike tire sizes (17" front).

My next bike purchase will have wheels large enough in diameter to get real knobbies, which will allow safe use of even longer studs. I will buy more studs then since I am reasonably happy with the basic premise of the studs.

Having just killed a brand new set of tires and about 130 studs in less than 250 miles, I won't be trying them again on a street bike.

If anyone is curios as to why I let it go for 18 punctures, the tires held up fine for the test ride and did not develop real problems until about 150 miles into a trip. Then they very quickly died as the tires ran out of slime. I would highly recommend using them just around town for several hundred miles before taking any trips, just so you will know what to expect.

Matthew -Matthew McLaughlin