Saturday, 18 June 2011 [63,469 miles]
Yesterday, on my way home from Pacifica, my tire pressure monitor was never able to read the pressure from the rear wheel. Eventually the TPM console started blinking its yellow warning light and displaying E1 (error 1, I assume). I suppose I should do something about it.
Today I added some air to the front as it was down a few pounds. The current rubber on the front has leaked air, slowly, since mounted. When I spun the rear wheel to access the valve I hear the sounds of loose items in the tire. Oh. Oh. I really need to do something about it. Now.
I took the tire off the bike and heard even more scary sounds. After breaking the bead and getting one side over the rim I found the source of my noises. The steel band that held the TPM sensor was in two pieces. It broke. The gear mechanism that tightens the band had also fallen apart. The largish sensor was rattling around the inside of the tire. What amazes me is that I didn’t feel it.
Tire Pressure Sensor
This image from 2009 shows how the sensor is supposed to be attached to the wheel. The break in the metal band occurred about 180º from the sensor, where the band turns from solid to slotted for the gear mechanism.
I removed the pieces and took the tire completely off the wheel. I’ll need to source a new band If I’m going to put it back. Not 100% sure I’ll do that. In the meanwhile I cut power to the TPM console so it won’t keep blinking at me, complaining that it can’t read the rear sensor. I also took a close look at the K60. There is still plenty or rubber left, but the tire is squared off more than I like. Since I’ve got a new Conti Trail Attack that I ordered not that long ago (it was on sale) I’ll mount it instead. The rear K60 (pre-Sport model) lasted 6,072 miles. My previous rear tire, another Trail Attack, lasted over 10K. The K60 didn’t impress me enough to make it worth 4K less miles.
A good side effect of removing the sensor is in the amount of weight needed to balance the wheel went way down. Don’t know if that means anything since I didn’t feel the sensor and metal bits rattling around in the tire, anyway.
Update: the sensor I removed sounds like a rattle when shaken; a rattle with lots and lots of small bits inside to generate noise. It didn’t do that when it was new. Since Smarttire doesn’t make systems for motorcycles any more I’m not going to bother looking for a replacement sensor. I removed the console and will remove the front tire sensor next tire change.