Tyres "blowing off" of the rims

Tegglington

I work for a print company, and work in a converted warehouse, I cycle 6 miles to work.

At around half 4 yesterday we heard an almighty bang, it was like a cannon going off.

We ran into the warehouse and couldn't see anything. We thought some racking had come down. Someone from upstairs (offices) even came down to ask if we were alright.

At half 5 i went to get my bike, and there was slime everywhere, my innertube had ruptured, blowing the tyre off of the rim! sending slime everywhere, so thats what the bang was! so ran for the bus, missed the bus, had to find another bus stop etc etc, didn't get in until 7. shot up to halfords last night to buy a tube. Got a lift in this morning, checked the bike over only to find my front has blown off during the night. so need another tube now!

does anybody have any idea what may have caused this?

I have a Specilzed Sirrus, running conti tubes and schwalbe marathon plus tyres (700 x 32) I pumped my tyres up night before and was probably pushing it a bit too much. could the tubes have got too warm during the day and just expanded?

are there certain things i need to check when repairing at lunch today? I will throughly check the tyres to make sure they are ok, and will check the wheels haven't buckled ot bent in any way.

any idea's as to how this may have happened or what to look for greatly appreciated, I'm just glad i wasn't near the bloody thing before it decided to blow up!

thanks

Warren

saladdays

This is one of the great mysteries of cycling, it happened to me when I was young. Probably a faulty tube.

You don't need slime tubes with Marathon Plus tyres. Make sure they're the correct size. I use MIchelin tubes: http://www.chainreactioncycles.com/Mode ... elID=58741

rolf_f

Lessons to be learned include:

1) Don't buy tubes with slime in them (keeping your tyres pumped up works just as well)
2) Carry spare inner tubes (x2) so that if you do get a puncture (or blow out) you don't have to waste time looking for buses.
3) If you must use slime, at least use tyres that warrant it. You could probably cycle through a barbed wire factory on Marathon pluses at half pressure with normal tubes and still not get a puncture. To get a puncture with slime and Marathon pluses would probably require a direct missile hit. It's overkill! Punctures don't matter that much!
4) Get a track pump with a proper gauge - you probably didn't actually overpump the tyre at all but either way, you need to get the pressure right - guessing isn't a good idea.

WeFixAnyBike

general reasons for blow outs

-Damaged rim that cannot grip the bead, did you hit any potholes on the way to work.
-damaged tyre bead/tyre was the tyre damaged in the blow out. if the tyre is fine it may have not been seated correctly, if there is no visible damage to rim.
-direct sunlight has caused it before, but im assuming it was inside by the sounds of it

desweller

Can also be rim failure due to wear or over-pressurised tyres, if they're cheap wheels. The rim surface should be straight and vertical; if it's concave then it's time to replace it.

Tegglington

Thanks All

I was running slime in tubes before I had the tyres, so when i got the new tyres didn't think it was a problem just using the old slimed tubes.

After a week or so of putting new tubes in its running ok, but the wheels are rubbing against the brake pads, once every full revolution. Could this be down to the rims now being bent? or just that the wheel isn't true?

Is it worth trying to true the wheels myself? I've never done it before, is it really that difficult?

or do I just take it to my LBS and get them to have a look at it?

I'm scared that the rims are gone, as this could get expensive. Is it best to just buy replacment rims? and get my LBS to rebuild the wheels, or just buy whole wheels?

bit lost now... not sure what to do...

shouldbeinbed

don't panic. I'll be astonished if it is the tubes that are the issue & your rims sound like 99% of everyone elses with a little ding in 'em. You don't say how old the bits & bike are or how much you've ridden them before this has happened - that could be a factor that affects some of the blather below - I'm assuming they're fairly new & low mileage.

Damaged or missing tyre bead or a dent/break in the rim lip (inside where it grips the tyre) is most likely to cause the explosive deflations. Either fault will act like a grenade going off as the high pressure tube tries to force itself out of a tiny gap, causing a messy big rip in the tube and literally exploding the tyre off the rim. It'll hold for so long but a minor bump if riding or a change in temperature/slight knock when standing can be all it takes for Kaboom to happen.

If its the rim then it is either badly out of true (fixable but strange to fail like this) or has had a chunk knocked out of it / random & odd integrity failure which would more likely mean it is replacement time - you could try the manufacturer for a warranty replacement but depends on other factors.

I had exactly the same with a faulty marathon plus 700x38 tyre on a new bike a couple of years back. there was no bead for a couple of inches and the explosions were quite spectacular - It took a couple of weeks & close examination to spot it as the rubber was intact and the little parallel lines of the tyre bead were there all the way round, it was just the internal 'wiring' missing. There was nothing for the rim to clinch onto at that point, tyre pressure & surface tension held the tyre in place for so long, but any slight deformation or pumping it up too quickly = a deafening and spectacular BANG and a rip in the inner tube up to 6 inches long. I sent a couple of pictures of the affected area to Schwalbe and got a replacement tyre free by return delivery, Its been fine on the same rim ever since - my marathon winters go on the same rim and have never punctured - the metal hoop didn't suffer from half a dozen big explosions.

As for the pad rubbing once per revolution. Unlikey to have catastrophically affected the rim as metal is tougher than rubber and it takes lots of miles of proper braking to wear down even pretty poor rims & Specialized standard kit won't be the worst in the world. It's way more likely just to be slightly out of true than having worn down the rim to such an extent & leaving an unworn bump to catch on.

First thing to check is that the wheels are properly seated in the forks on both sides & not running askew - That wouldn't normally give a single area of rub on just one side though. It's easy to tell though by (ideally taking the tyres off) getting the bike upside down, loosening off the wheel nuts / opening the QR lever and spinning them to make sure they are running central and parallel in the forks.

I assume from your description it is a very short touch and doesn't stop the wheel dead in its tracks first spin, 99% of bikes will have that, its a loose spoke or two or having caught a pothole or grid a bit hard when riding - again unlikely the blowouts will have deformed your rims significantly (soft rubber, hard metal)

Theoretically it's in the realms of a home fix - the thing to remember is you're needing to maintain the spread of tension evenly across the whole wheel, not necessarily just tweak the spokes in the area where it rubs - unless they're obviously looser and just need a careful tighten up to the same 'twang' as the rest. There's plenty of truing advice and videos though Google but it depends how competent and confident a mechanic you feel you are.

However reading the worried tone of your last post I would suggest you have a chat with the LBS and let them have a look at it for a proper visual diagnosis before you do anything. Truing a wheel is a relatively quick easy and cheap job for a competent and honest LBS. if you're not careful at home you can make your rim a lot worse and have spokes popping for fun.

Glynno

This make of tyre (Schwalbe) is still doing this. They are rubbish. Bought some from Cycle King in Oxford and when I took them home and put on my bike they just popped taking the inner tubes with them. Took them back to Cycle King and they were clueless :oops: , as with a lot of other stuff, but thats another story. I was told that they were over inflated - THEY pumped them up :oops: . I was told they shouldn't be pumped up above 80 psi - they have 130 psi max printed on them :oops: . 5 times the same thing happened :oops: . Cycle King eventually offered me 20% off some new ones :x . I had hardly ridden the bike as the tyres were always popping. Then Cycle King tried to blame me after I replaced the inner tubes they supplied which had completely blown in half as if being sliced by a knife. I replaced them with a tube from BeeLine Cycles. That's yet another story . I decided that I had bought a rubbish tyre from a rubbish Cycle King so went to Merlin Cycles on line and bought 2 Michelin tyres and one tube with green stuff to ease punctures . These tyres and tube arrived over night . Great ride and staying on the wheel . Result - 1. My life is no longer in danger . 2. Dont use rubbish tyres and tubes. 3. Don't use a rubbish Cycle King. 4. Don't take bike to BeeLine for a service. 5. :idea: Buy much cheaper on line from Merlin Cycles and service the bike myself - far better job. HAPPY BIKING

The Rookie

Never to be seen or heard of again I guess.....emoji overload!