I fitted a brand-new pair of Schwalbe Marathon Racer tyres at the start of this year. I've just noticed that there are quite a lot of very small cracks in the side wall of both tyres. (The tread is still good though). Even using a worst-case estimate, I've only done about 3200km this year. Schwalbe say the Marathon Racers should last at least 5000 km?

The cracks are very small, somewhere between Fig.1 and Fig.2 on the website. The bike has been stored indoors when not in use. They have been great tyres but I'm wary of spending that much on tyres if they need replacing every 8 months.

Tyre cracks

The cracks look like this in various patches most of the way round both sides of each tyre.

Addition: Took the tyre and inner tube off to inspect. I can't see anything like the 'ripples/waves' in the Schwalbe pictures. Most of the slits are in the same position as those pictured above, i.e. between the start of the tread and the dynamo track. (A few are slightly lower though).

  • I wonder if they are not so suitable for urban? commuting (the roads can be quite potholed near where I live)
    – decvalts
    Jul 17, 2014 at 11:31
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    It sounds like they've been ridden with too little pressure. How much pressure do you run? Jul 17, 2014 at 12:10
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    You should get a decent "floor pump" with a gauge, and check the tires at least once a week, more often if they tend to "leak down" fast. A frame pump is good to have but you can rarely get the tires up to proper pressure with one. For normal urban commuting you should be running at least 50 psi, probably 75 or so, depending on the specific tire. Jul 17, 2014 at 12:37
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    As a point of reference, I use a good floor pump with a pressure gauge, and always keep the tires near the recommended inflation (80 psi on 700x32) and I still get cracks similar to shown in Fig. 1 in the link, although I don't use Schwalbe tires.
    – Kibbee
    Jul 17, 2014 at 12:44
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    According to Saint Sheldon, the outer rubber is not structural other than to keep things from poking into the casing. So if the sidewall has cracks it's not really a problem. sheldonbrown.com/tires.html
    – obelia
    Jul 18, 2014 at 0:57

2 Answers 2


Not really an answer, but I put it here to separate it from the comments about using a decent track pump...

Daniel R Hicks makes a good point about the cracks - they seem to be between the tread and sidewall. This suggests to me that there are two different rubber compounds that aren't "mating" well. According to a few mechanics I know, Schwalbe have had some quality control problems in the last year. I can second this - the relatively recent Ultremo racing tyre range have had some decidedly dodgy sidewalls, and I've had one which separated from the main tread strip within weeks. However, other sets seem fine and are some of the most comfortable, grippy tyres I've ever ridden, and they're lasting.

Unless you've kept your tyres in direct sunlight all year, I'd suggest it's a rubber/adhesive issue. Try contacting Schwalbe and see if this is a warranty issue... after all, Marathons are made for milage and aren't cheap!

  • (will delete if this answer would serve better as a comment or two) Jul 19, 2014 at 8:21

This doesn't seem like a terrible issue. You should be able to ride on these tires for awhile longer. I've seen people with super cracked tires ride for multiple months without issue.

Oftentimes, cracks like this happen because of over inflation and exposure to the elements. To keep the tires viable for as long as possible, I would recommend keeping the bike inside when you're not using it, and leaving the pressure between 60 and 80 psi.

  • Can you expand on why cracks are caused by over inflation? In the link from the question the manufacturer states that cracks are caused by under inflation (or ageing).
    – Hugh W
    Jun 4, 2022 at 9:29

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