What would cause a tyre to bulge?

by thebungle   July 15, 2013  

My wife has been riding her new bike since May, it came with a 'lovely' set of Maxis Detonator tyres, pretty nasty tyres and due for replacement sooner rather than later.

We were out riding yeserday and after stopping for a cheeky ice-cream at the 15 mile point we noticed a bulge in the very top centre of the tyre, like a rubber 'boil' on the surface, having no other choice but to attempt to cycle home off we went, sure enough after 2 miles the bulge started to rub on the frame it was getting that large, one mile later POP it went, ride over.

Now, I realise that the tyre fitted isn't the best in the world but I would expect more than 400 miles from it, I've seen a sidewall bulge after several thousand miles but never a bulge on the top and after so little miles.

Should I expect this? Is there anything I can do to avoid it? Should I go to the LBS and kick off demanding free tyres for life?

4 user comments

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"pretty nasty tyres and due for replacement sooner rather than later" You have answered your own question here!
If your LBS are any sort of gents they would possibly keep you sweet with some money off a good quality replacement tyre, but free tyres for life would be nice! 400 miles is nothing.
The only reason I can think of for a tyre to bulge (other than being of faulty manufacture) is a long skid? Or stone damage.... I would hope that they would at least be interested in the cause of the failure and possibly sent back to the manufacturer, the tyre does not seem to be fit for purpose. Making an issue using the Sale of Goods Act is an expensive option and unlikely to be worth the potential expense.
See what the shop say; if they get shirty then either find a better shop or tell them you wish you had bought the bike off the internet... that should smart Devil

posted by SideBurn [913 posts]
15th July 2013 - 9:35


Just buy some new tyres for the bike, the tyres you get with bikes are normally always terrible.

posted by SammyG [295 posts]
15th July 2013 - 9:41


I work in a tire shop. Bulges are separations in the layers. More likely than not, it's manufacturer error

[custom] '12 Cannondale CAAD10 - Rival

badkneestom's picture

posted by badkneestom [134 posts]
15th July 2013 - 12:09


Thankfully they are a very good LBS and I'm sure they will offer a good deal on replacement tyres, there was certainly no skidding on the tyre and no obvious sign of damage, although 'we all know' tyres that come with bikes, even at £800 are are 'rubbish' I still feel they should last more than several months!

posted by thebungle [115 posts]
15th July 2013 - 12:09