When should I replace my tyres?

Baron_Kunkel

I have a roadbike for a 22mile round trip commute. 700 x 25c size tyres.
I've noticed 3-4 small cuts (right through) in the rear tyre all about 5mm. Do I need to change them?

Beasty

According to Sheldon

Tire Wear-When should you replace your tires?

Many cyclists waste money replacing perfectly functional tires simply because they're old, or may have discolored sidewalls. If you just want new tires because the old ones look grotty, it's your money, but if you are mainly concerned with safety/function, there are only two reasons for replacing old tires:

1. When the tread is worn so thin that you start getting a lot of flats from small pieces of glass and the like, or the fabric shows through the rubber.
2. When the tire's fabric has been damaged, so that the tire has a lumpy, irregular appearance somewhere, or the tube bulges through the tire.

Cracks in the tread are harmless. Small punctures in the tire such as are typically caused by nails, tacks, thorns or glass slivers are also harmless to the tire, since the tire doesn't need to be air-tight. Gumwall tires sometimes get unsightly blistering on the sidewalls from ozone damage. (This is frequently caused by storing the bike near a furnace--the powerful electric motors in typical furnaces can put a fair amount of ozone into the air.) This blistering is ugly, but doesn't actually compromise the safety/reliability of the tire in the least.

In summary, if you're not getting lots of punctures they should be OK - the small cuts should be fine (so long as they are small)

Chips Lovell

An upsurge in punctures is usually the red flag for me too. On occasion, it's been ridiculously worn thread, but you usually start flatting a lot before that happens.

carthoris

Baron_Kunkel wrote: »

I have a roadbike for a 22mile round trip commute. 700 x 25c size tyres.
I've noticed 3-4 small cuts (right through) in the rear tyre all about 5mm. Do I need to change them?

If you are not getting many(/any) flats they might be ok for another while.

Can you see the tyre through the cuts ? If so you could "patch" the tyre by supergluing the cuts together, and for bonus points you could also glue small cuts of tube onto the inside of the tyre to cover the hole and hold the tyre together.

Swapping the tyres so the worn one goes onto the front might also reduce the risk of getting a flat. I generally notice that the rear tyre gets much more cuts and flats.

If all that sounds like too much work, then it is time for new tyres

Beasty

carthoris wrote: »

Swapping the tyres so the worn one goes onto the front might also reduce the risk of getting a flat. I generally notice that the rear tyre gets much more cuts and flats.

Put the good one on the front;)

tomasrojo

Beasty wrote: »

Put the good one on the front;)

I was just going to say that. I do rotate the tyres after about four months or so, or when the first fissures appear in the rear tyre, but you really do need your front tyre to be in very reasonable condition.