3 flats in 650 miles (1030 km) on hybrid bike. Tire pressure wrong? I have a Giant hybrid (with 700x32c 65 PSI tires), stock tires, that I mainly ride on nice roads to and from work ~3.5 km/2.2 miles each way.  I weigh 230 lbs/104 kg up from 200 lbs when I bought the bike sadly two years ago.

I check my tire pressure before I start riding again (If it's been more than 2 weeks) or every week. And I've put about 640 miles on the tires, but in that time I've had 3 blowouts. 

That seems like a lot.

After doing a bit of reading it feels like my tires might be under inflated (I have a decent floor pump I use and I try to keep it right at 65 PSI) for the weight load (270 lbs/122 kg including bike), but I can't tell.  I haven't measured displacement under load (I'll do that when I get a new inner tube) to see if it's above 15% or not, but I don't thing there's any tire or rim damage that would be poking the tube either.

How do I tell what's causing the frequent blow outs?  Low tire pressure or too close to the limit?  Or are my expectations wrong on how often they occur?

edit: Okay, I removed my back tire and inspected the tube and there's a small hole bigger than a pin prick around the size of a pin head. There also seems to be pitting/cracking on the inner tube (Forte 200x28-32C made in Taiwan 2012 37 03).


This appears to be the puncture.



Do I just have low quality inner tubes? I've just been having the bike shop I bought the bike at replace my tubes.

General guide for optimum tire pressure on a road/mountain bike

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Depending on your attentiveness while riding, the hazards in the area you ride in and a few other factors, that may be a reasonable amount of flats.  I know a few commuters in my area that expect roughly a flat a week in their roughly 100 mile weekly commute.  I've ridden with this particular pair of guys, however and found they have a tendency to shortcut through glass filled abandoned parking lots and the like, and they don't pick careful lines through that mess.

I will say this about flats, when you change a flat, you should always figure out why/how you got the flat.  If you don't, you'll just get the same flat again.  Pull the tube, keep it oriented, re-inflate it and figure out where the hole(s) are.  There are articles out there telling you where to look based on the placement of your tube holes and their configuration.  If you are getting repeated puncture flats from objects, you may consider switching to more puncture resistant tires.  Keep in mind more expensive does not mean more durable.  I've bought ultralight and expensive race tires before that didn't make it 13 miles around a loop before picking up 3 punctures from gravel that wasn't even that sharp.  I ended up switching to a much heavier but more puncture resistant tire that was 30% cheaper and hasn't had any punctures since.  I don't race, so that works fine for me.

If your awareness doesn't keep you out of glass patches and the like (or they are just unavoidable in your area, I am pointing at you Honolulu) and you get repeated puncture flats, you may also consider switching to a tubeless setup with juice in your tires to minimize the impact of these.