When to replace a tire

My saga of the hard-to-seat tire got me thinking about tire replacement in general.  As I said, I felt it necessary to buy a new tire because of my upcoming MS 150, and I wanted it in time for last weekend’s 52-miler.

The original tire was new in February.  Because of its kevlar tread, I was hoping for some puncture resistance.  But I don’t think anything could have survived the piece of glass that got this tire.  It was kind of a fluke, too, because the cut was duplicated halfway around the tire.

They weren’t even cuts, exactly — more like a hole, about an eighth of an inch in diameter. When I ran my fingers over them, I could feel a slight bulge right around the hole itself.  It didn’t affect a larger area around the holes.  Because the holes weren’t big, I decided to keep riding on the tire.

The next day, I did a club ride for 38 miles on city streets and rural country roads.  No tire problems.  In fact, I didn’t even think about the tire.  It’s been on several rides since then, for a total of a bit over 200 miles.

When the replacement tire arrived in the mail, I didn’t change it immediately.  I was even considering doing the 52-miler on the damaged tire, since it seemed to be performing fine.  But I happened to be  sitting in the living room reading a bike book, and it said, if the tire is cut, the cut could turn into a puncture.  If it bulges, it will turn into a puncture more quickly.

I went out to the garage and took another look at the tire.  Not only could I feel the bulge, I could see it. That’s when I had my wrestling match with the replacement tire.

I know of some riders who are rather cavalier about their tires.  They’ll ride until they see the tube pushing through the tread, or until it wears down to the threads.

What’s your rule of thumb for replacing your tires?  How far or how long are you willing to ride when you know the tire is less than 100 percent?


  1. scshop says

    I’d have to say that I probably usually fall into the cavalier category when it comes to my bike tires. On my old Trek I rode the already bald tires several hundred miles over the course of a summer before I ever did anything about replacing them and really had no problems. However, if there is a gash in the tire as has recently happened on my MTB, I usually go ahead and replace it ASAP just to avoid any catastrophic mishaps.

  2. says

    I have only recently began bicycle commuting (so I haven’t been doing it long enough to warrant a replacement of tires), but I can say that I’d replace a tire if it has cuts in it (like you described on yours), or when the tread wears down to bald. Basically, I’d treat it just like I treat the tires on my car, since my bike is, in effect, my mode of transportation.

    It’s no fun to be stuck hoofin’ it somewhere in the event of a mishap, especially one that could have been prevented by good maintenance. :)

    Best (& nice blog, btw!),
    Heather S. Ingemar

  3. says

    Regarding flats and tire replacement…if I have a “through and through” cut or puncture that is big enough to see daylight, I won’t ride on it unless I put a boot in the tire. In my experience, I’ll usually have another flat within 50 miles if I don’t line the tire. The boot might be a real one from Park Tools or other supplier, or simply a dollar bill that I use to line the tire during a ride. I’ll usually ride on the boot until I get another good size hole requiring a boot, then I’ll replace the tire. Of course, this doesn’t have a lot to do with normal tire wear…I’ll leave that for another day!

  4. says

    My current tires have about 1500 miles on them. Before the MS150 I’m planning on replacing the rear tire but will most likely leave the front tire in place. Who knows…I might change it out too. I could definitely get some more miles out of these tires but the back tire is getting pretty warn, to the point that the profile is starting to get squared off! I know lighter folks get around 3k out of these same tires…but I’m not of the lighter persuasion!

  5. says

    My rule of thumb is waiting until the tire is in bad enough condition that it has to be replaced, which means it’s not a rule of thumb but rather a bad habit! This also means I’m far too willing to ride a less than 100% tire for far too long. I’ve used the dollar bill trick that 331 mentions and it works great…so I always place a couple of $1 bills with the patch kit.

  6. says

    Another good choice for a tire boot is to cut a strip from an organized ride number. Those things are made of an unrippable compound, and you’re not stashing some hard-earned money inside a tire!

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