For the last week or two, I’ve been perplexed by the tire pressure monitoring system on my bike. Sure, we’ve had some temperature fluctuations, but the air pressure fluctuations in my rear tire seemed a little…odd. And the TPMS wasn’t super-aligned with my tire pressure gauge (and they’ve been pretty solidly aligned up until recently). A few days ago, as I was noticing losing a couple PSI every couple days, I started to suspect that I had a slow leak.
This morning, I hopped on my bike to head to work and my TPMS indicated 37 PSI on my rear. Factory spec is 42, and I tend to like to run at 43 simply because I’ve found my tires wear more evenly ever-so-slightly over-inflated. Yesterday, I’d added air and had 42 PSI. That’s a pretty big drop overnight, so I turned around, parked the bike, and grabbed a ReachNow to head to work.
We checked my tire tonight (gotta love the soap and water trick) and found that the plug I installed several months ago was leaking. Scott replugged it, and it’s still leaking. Methinks we’ll be popping the tire off to install a patch on the inside of the tire, because there’s still plenty of tread left.
Lesson learned: You’re not likely to have a catastrophic plug failure. You’re more likely to eventually develop a slow leak, and if your bike has a TPMS system, you’ll be alerted to the problem before your tire loses enough pressure to be really problematic. You just have to put a little trust in your TPMS and double-check manually if things seem a little funny.