# Sidewall blowout Marathon Plus...



## Kell (15 Aug 2017)

Yesterday, while descending a pretty steep hill (44mph top speed), the sidewall of my fairly recent Marathon 
Pluses blew out in a spectacular fashion. It sounded like a rifle shot.

Luckily, at that point, I'd slowed to around 30mph and managed to bring the bike to standstill without coming off.

Could it be too much on the brakes? I've heard this can heat up the rim and cause tyres to blow, but I'd assumed these tyres were pretty indestructible.

Chalk it up to experience or press Schwalbe for an explanation? I cannot find where I bought the tyres from, so don't know how long they've been fitted, but I'd estimate that it's less than a year so +/- 2,500 miles on them.


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## 12boy (15 Aug 2017)

We had a discussion of this before...all tires with rim brakes heat up with extended braking, and 16 and 20 inch wheels would seem to be the worst since there is a smaller rim area to dissipate heat. Doing down long stretches in mountains might require cooling off periods. Some techniques are to alternate braking between front and rear brakes, sit up so as to generate more drag, run less air pressure than normal and pour water on the wheels to cool them down. I have in the past damaged Schwalbe tire beads with a steel tire lever getting the tires on the rim, and had the sidewall separate from the bead while riding. Sounded just like a gunshot and people came out of their houses to see who had been shot. I an glad you are alive and unhurt as a blown tire at speed is so dangerous.


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## KnackeredBike (15 Aug 2017)

Do you have a picture of the tyre? It could be a manufacturing defect but I would say more likely it's been damaged at some stage.

Schwalbe are a bit cagey about what it in their "Smartguard" puncture protection but as with any joining of different materials with different expansion when heated the join between Smartguard and the sidewall will always be a weak point.


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## Rooster1 (15 Aug 2017)

blimey, very insightful post. never considered brake heat could do such a thing.


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## MrGrumpy (15 Aug 2017)

or brake pad was rubbing on tyre ? ( speaking from experience )


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## Kell (15 Aug 2017)

MrGrumpy said:


> or brake pad was rubbing on tyre ? ( speaking from experience )





OK. 

That was my first thought too. So i checked the alignment on the pads when applied and there's no way they were touching the tyre.

BUT

When removing the old tyre today to fit a new one* it did indeed look like there was some rubbing. So I checked and checked again and finally by accident noticed that the whole front caliper was loose and would rock forwards under braking. 

So applying the brake stationary meant the pads gripped the rim flat and away from the tyre - so a visual check meant that everything looked OK. But under actual braking conditions, they would lever forward and touch the tyre - hence the flat. It's clearly rubbed it through, caused the tyrewall structure to rip, expose the inner tube and cause the massive blowout.

I'll be sure to keep an eye on stuff like that in the future and would urge everyone else to do the same.

*Marathon Plus at £23.95 on Merlin Cycles currently and took less than 24 hours to be delivered if anyone's interested https://www.merlincycles.com/schwalbe-marathon-plus-smartguard-touring-tyre-16-100852.html


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## mjr (15 Aug 2017)

12boy said:


> sit up so as to generate more drag


Not only that, but stick your knees and elbows out, and open the front of your jacket or jersey to make you a big air brake.


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## mjr (15 Aug 2017)

Kell said:


> I'll be sure to keep an eye on stuff like that in the future and would urge everyone else to do the same.


Yes, you need to put the brake on and push the bike forwards both to check the brakes are firmly attached and to check the headset isn't coming loose!


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## CopperBrompton (15 Aug 2017)

Just don't brake. On a 10-mile downhill stretch, assuming no traffic, you'll have no problems at all for 99.999% of the ride.


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## Tail End Charlie (16 Aug 2017)

Strangely enough I had the same on my tandem a week ago. Fortunately I was going quite slowly but the sound was like a shot as you say. The tyre looked OK so I refitted but had difficulty getting it to stay on the rim, the tube kept coming out from under the tyre. Eventually managed to get it to stay on and rode home. Didn't think about it and went off for a couple of nights to mid Wales. First day it blew off again, so I ended up getting a new tyre (fortunately I was about a mile from a bike shop). It was a Marathon Plus which had plenty of tread still on but I can't say how old it was. I do run them close to the max recommended pressure though. Perhaps I should reduce it a bit. 
My wife was very shocked at the sound of the tube going.


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## Tail End Charlie (16 Aug 2017)

I mean the first tyre which blew off was a M+ , obviously I replaced with a new one (standard Marathon).


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## gaijintendo (16 Aug 2017)

mjr said:


> Not only that, but stick your knees and elbows out, and open the front of your jacket or jersey to make you a big air brake.



If my rain jacket thinks I'm going too fast it unrolls and deploys its hood. Montane KAM-G09 if you wish to replicate this safety feature.


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## Kell (16 Aug 2017)

This it the tyre after I repaired the tube. 

Hadn't realised that the tyre had also split until I pumped it up. 

It's a moot point now as I'm going to put this one down to user error.


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## KneesUp (16 Aug 2017)

I was tipped over the bars of a bike as a kid because the front calliper was loose - the retaining nut fell off, so when I put the brakes on the wheel pulled the calliper from the forks and once the slack was taken out the brake cable I was launched onto the A34. Luckily the bike and I landed in an empty bus-stop-layby thing. It' something I check quite often now.


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## srw (16 Aug 2017)

Kell said:


> This it the tyre after I repaired the tube.
> 
> Hadn't realised that the tyre had also split until I pumped it up.
> 
> ...


Crumbs. Glad you're OK.

I presume this was either Amersham Hill or Marlow Hill, and so either way rather trafficked? How is the rim of the wheel?


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## Kell (17 Aug 2017)

Yeah it was Marlow Hill. 

I've been keeping an eye on the rim after my rear wheel split. 

It's still ok, but I think will need replacing soon.


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## Dan B (17 Aug 2017)

CopperBrompton said:


> Just don't brake. On a 10-mile downhill stretch, assuming no traffic, you'll have no problems at all for 99.999% of the ride.


"I'm not afraid of heights, I'm afraid of grounds"


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## glasgowcyclist (17 Aug 2017)

Kell said:


> This it the tyre after I repaired the tube.
> 
> Hadn't realised that the tyre had also split until I pumped it up.
> 
> ...



I had a blowout just like that on a M+ tyre that had less than 100 miles on it, and it happened while the bike was locked in the bike shed at work.

I returned it as faulty and got a new replacement after a week or so (German retailer online).


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## BarnesCommuter (23 Aug 2017)

glasgowcyclist said:


> I had a blowout just like that on a M+ tyre that had less than 100 miles on it, and it happened while the bike was locked in the bike shed at work.
> 
> I returned it as faulty and got a new replacement after a week or so (German retailer online).



Same thing happened to me - pumped up the tyre yesterday without any apparent problem, went to use it this morning, only to find the tyre was flat with the sidewall blown out.


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