15

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?

6
  • 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
    Commented Feb 18, 2013 at 9:37
  • 1
    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
    Commented Feb 18, 2013 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
    Commented Feb 18, 2013 at 20:34
  • Don't rule out the possibility of randomness. Commented Feb 19, 2013 at 4:11
  • 3
    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. Commented Feb 19, 2013 at 8:47

6 Answers 6

23

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.

4
  • 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. Commented Feb 18, 2013 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
    Commented Feb 18, 2013 at 12:33
  • 1
    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
    Commented Feb 18, 2013 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
    Commented Feb 18, 2013 at 19:27
7

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.

5

In the past year, have gotten 5 rear flats and 0 front, while riding in bike lanes. 3 flats were caused by small metal pieces, 1 by a thorn, and 1 by a screw. Suspect that the front wheel lifted up these items and the rear wheel rode over them at a puncture angle (straight into the tire). This must be happening since the metal items would normally lay flat on the ground, explaining why flats are on the rear. Am riding 20+ mph, which means the rear tire passes over where the front was very quickly.

4

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 :-)

1
2

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.

0

Your rear spokes are loose. As you land on your rear wheel from a jump, the rim flattens at contact and the spokes momentarily protrude into the tube.

2
  • 1
    Hi, welcome to bicycles. Spoke punctures would be obvious, though, because they'd be on the inside of the tube not the outside.
    – DavidW
    Commented Apr 25 at 16:39
  • 2
    Welcome to Bicycles SE. The community tends to frown on posting answers that are substantively the same as existing answers and someone else has already suggested that loose spokes may to be to blame. If you have a different perspective, please edit your answer to highlight the differences between yours and the other answer. Otherwise, I'd recommend deleting it so that it doesn't get downvoted by the community. Please see our help pages or take our tour for more information about how the site works.
    – jimchristie
    Commented Apr 25 at 17:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.