Friday, 24 Jul 2009
Conti Trail Attack
Old tire
The Conti Trail Attack I ordered about three weeks ago arrived just before Mitsuko and I left town for a few days. I finally got around to mounting it this afternoon. The bike had been sitting since I noticed the steel belts poking out of the old tire. That tire, a Tourance, lasted 10,700 miles. I’m trying a Trail Attack this time just because.
Just in case
Yeah, adding the safety strap is a bit over the top, but I have the strap so why not. It only adds a minute or two to the time, not that I’m ever in a hurry when working on the bike. If this one isn’t ready to ride when I need a bike I’ll ride the other.
Needs rebalancing
Removing old tire
The old tire comes off. Note the amount of extra weight. You might think the old tire was pretty bad. Not so. That weight was primarily to counteract the combination of an out of balance wheel plus TPM (tire pressure monitor) sensor.
After removing the tire I spent quite a while cleaning the wheel. A green scotchbrite pad took care of the crud around the bead area of the wheel.
Where’s the heavy spot?
After TPM added
The first picture shows the wheel balance without the tire, TPM, or wheel weights. Note that the valve stem is UP, indicating it is the lightest spot of the wheel. The assumption is usually that the valve stem is the heavy spot, and for that reason the TPM sensor was originally installed opposite the valve stem per the installation instructions.
What that did was add extra weight to the heaviest spot of the wheel. Ooops. I moved the sensor near the valve stem. The second picture shows the balance of the wheel with the sensor installed.
Guessing weights
Extra weight for tire
I decided to balance the rear wheel before mounting the tire. I had good luck doing this on the front. When I mounted my front tire the balanced wheel was fine. In this case I needed to add a bit more weight to get the balance perfect.
Ready to roll
While the wheel was off I took a damp rag to parts of the bike normally not seen. I made sure to clean the mounting flange, checking for any cracks where the brake disk mounts. All is OK. The wheel went back on the bike, torqued to spec (60 Nm). The GS is ready to ride, again.