New Tires!

I finally bought new tires for my motorcycle, replacing the original Dunlop's that came with the bike with a new pair of Metzler tires. Before I go on, if you're not a biker you won't appreciate how excited bikers get about a new pair of tires. I'll try to keep this relevant to non-bikers, but be warned that you might want to bail out now.

Having a shop install the tires is really expensive. If I brought in the tires, the shop near where I work would charge me $175 to put them on the bike. So instead I invested $50 in a torque wrench and metric sockets and took the wheels off the bike myself.

Taking wheels off a bike isn't that hard, but because the wheels are directly tied to the braking and drive systems, it is a little involved. Fortunately once I had the right tools it wasn't that hard. The front wheel was extremely easy because it uses a disc brake. The drum brake and the chain on the rear wheel was a little more involved. I had to run to the store twice in the process: first, when I realised that my largest metric wrench was only 19mm, but the front axle nut was 22mm. The second, when I realized that the rear wheel axle nut was 27mm and I had to run to Auto Zone to get an appropriate socket.

Great Lakes Power Sports was able to mount and balance the tires for me quickly, and I was back on my way home to put the wheels back on. This was a lot more fun. And by fun, I mean that I got to make several interesting mistakes.

The first mistake that I was aware of was squeezing the front brake before I had the calliper on the rotor (n.b.: don't interrupt wheel installation for dinner). If you've never done that, let me fill you in on a couple of details about brake callipers. First, brake callipers are designed to fit pretty tightly over the rotor. Second, callipers use the rotor to push themselves back to their proper position.

So what I had to do was open the brake reservoir to relive the pressure on the callipers, then use a screwdriver to very carefully wedge the brake pads open with a screwdriver. The pads spread just about enough to slip over the rotors if it's slid on very carefully.

By the time I had this worked out and some other essential chores taken care of around the house, it was too late to take the bike out for a test ride. That turns out to be a good thing, because later on I realized I hadn't tightened the pinch bolts that hold the axle securely in the forks. Now, the axle can't actually slip out, because the axle nut also holds it in place, but having anything unsecured on the front wheel is bad.

The other thing I found was that I hadn't adjusted the rear brake properly. This I found on my test drive around the subdivision, when the brake pedal had a few extra inches of travel. Fortunately the front bake was known to be good, and the rear did engage when sufficiently depressed (I had actually checked that before I rolled out). Luckily, rear brakes on a motorcycle are extremely easy to adjust. I hand tightened a nut on the drum's lever and everything was good.

Everything properly adjusted and the tires inflated to spec, I took off for a good test ride and some parking lot practice. The new tires had good grip, even when doing fiture eights at 25mph, and felt a good bit more responsive. I don't know if I can attribute that responsive feel to the better grip on the Metzler tires, or just the fact that they were new and had more than a millimeter of tread.