I've recently had a full flat with hardly any air left in my rear tyre when my road bike was in storage. Storage means my storage compartment in my appartment building's basement, pretty constant temperatur and just a tad humid. The odd thing is that it wasn't "linear" like a slow puncture/leak or instant failure, the order events was something like that:
- Day 0: No problems on the last ride, bike was in storage with perfectly inflated tyres, they might have lost some pressure since the last ride but way enough to ride it, if I had to
- Day 1: Inflate to correct pressure, ride without any issues, clean bike and put it back into the stand
- Day 2: I just revisted the bike because I usually let the lubricant sit and remove excess lube some time after the actual clean job - Tube all fine
- Day 3: It is my storage compartment, so I just went there to pick some other stuff - Tube still fine (I nearly walk into my bike, so I would have noticed if it was totally flat)
- Day 5: I wanted to go on a ride and it was totally flat with practically no air in it
I still had some time before my ride, so I didn't instantly change the tube to be on the safe side and just reinflated it - bit of a gamble but it held air just fine, made a four-hour ride without losing any air and is still fully inflated when I checked today, more than a day after the ride.
Do you have any idea what could be the issue, here? I've had that in the past and think I can rule out a loose valve head/core that was slightly screwed out by accident until the point of failure.
I run pretty standard Continental Race 28 butyl tubes matching my 25 mm clincher setup, nothing exotic or lightweight, and usually they hold air pretty well, so they keep my 7,0-7,5 bar pressure when there's only a day or two between rides. The tube isn't very old, I just put it in 3 months ago fresh from the package a few days after I bought it.
If my memory serves me well, I've had this one or two times before and re-inflating always did the trick, so I think the tube itself isn't punctured and I always check that the Presta valves are closed tight.
What is going on, here? Is this just a common thing because tubes/valves are not meant to be 100 percent airtight, am I doing something wrong or is it a thing that Conti tubes (despite their brand's reputation) can be hit and miss depending on the batch?
I wouldn't be worried if it was consistant (because I check pressure before rides, anyway) but that kind of behavior confuses me.
Of course, I checked some old posts but most of them were related to sudden deflation on impacts such as speed bumps, ramps or potholes but no occurrences after serveral days.