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up vote 11 down vote favorite

I get probably five times as many punctures in my rear wheel as opposed to my front wheel. I run a good pressure and don't get obvious pinch flats.

Does anyone have a logical reason why this could be happening?

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wild stab in the dark. If you see glass on the ground or something equivalently dangerous you will move your front wheel to avoid it but you cannot be sure you will prevent your back wheel from running over that same object. – robthewolf Feb 18 at 9:37
This is a normal ratio, at least for me and those I ride with. Sam's answer + Daniel's comment paints the probable picture. – Ken Hiatt Feb 18 at 15:51
I've never found anything lodged in the tyre itself but something may have been floating around in the tyre. Occured to me the other day as I was replacing my reasonably worn tyres and realised I still had the original tube on the front. I had two punctures alone in the last couple of weeks on the back. To be fair both of those tubes had been patched in the past. – DWGKNZ Feb 18 at 20:34
Don't rule out the possibility of randomness. – Quinn Culver Feb 19 at 4:11
1  
This observation seems to imply it might be a good compromise to run a heavier, more expensive, puncture resistant tire on the rear and something lighter on the front. – JamesBradbury Feb 19 at 8:47

4 Answers

up vote 19 down vote accepted

The back wheel is the wheel bearing most of the weight and also the wheel providing the driving force. For these 2 reasons it is likely that the forces being exerted between the wheel and surface are much greater on the rear wheel than on the front. This makes it more likely that you will get punctures on the rear wheel than the front - all other things equal.

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Also, I suspect that the back-and-forth motion of the front tire tends to "scrub" small pieces of trash loose. In any event, I have only ever had 2 front flats that I can recall, while I've had easily 2 dozen rear flats. – Daniel R Hicks Feb 18 at 11:35
One possible solution is to distribute the pressure in your tires to accommodate the distribution in weight (about 40% in your front, 60% in your rear. See: bikequarterly.com/images/TireDrop.pdf for more info.) – WTHarper Feb 18 at 12:33
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By any chance have you switched rear inner tube? A possible cause is a tube that is already chemically damaged or too old. Some of such tubes simply deflate and you find a hole in them but never find the offending object. It is like rubber pores getting too big. – Jahaziel Feb 18 at 15:20
I believe the extra weight on the back also increases the size of the contact patch, increasing the odds of hitting something sharp in the first place. – freiheit♦ Feb 18 at 19:27
up vote 0 down vote

Are the holes on the inner surface of the inner tube as opposed to the outer surface. It could be that one of your spokes is slightly loose, when you sit on the bike this spoke may be pushing into the tube slightly and causing the punctures.

Check the position of the holes and see if they're inside or outside, if they're outside then check for sharp objects pushing through the tyre as previously mentioned by someone else.

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up vote 2 down vote

Other effects: the front tyre can disturb something lying flat on the ground, flicking it up ready to cause a puncture on the rear; and taking a rear wheel off to fix a flat is more hassle because of the gears and so even if you have equal numbers of flats, the extra time spent on rear ones makes it feel like you have more rear ones :-)

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up vote 7 down vote

It is possible that something is stuck in your rear wheel tire. That piece of glass or metal can pierce the tube repeatedly, even after you repair the tube. This happened to me once. I repaired the hole in the tube and a day later another pressure loss. I finally realized that a piece of glass was stuck in the tire. You can feel with your fingers on the inside of the tire for sharp objects.

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