Marathon plus tyre failure after puncture.

General cycling advice ( NOT technical ! )
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531colin
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Re: Marathon plus tyre failure after puncture.

Post by 531colin »

Pebble wrote: 1 Feb 2023, 8:00am...............
If the wire is a closed loop which I think it is, how does the wire go over the rim? I can understand the tire now detached from the wire stretching, but the wire?............
The tyre is "detached from the wire" because I cut it open to show the fault in the construction.
The fault in the construction is that the wire bead isn't encased in rubber to glue the strands of wire together. (actually a single length of multistrand wire which passes a few times round)
So as you ride along, the wire slips and the bead diameter grows in a faulty tyre.

How does the wire go over the rim? The wire goes over the rim (in a "good" tyre) only because you put the bead in the well of the rim all the way round, except the last bit you are getting over the rim. When the bead is in the rim well, it gives you the slack to get the last bit of bead over the rim. When all the bead is on the bead seat of the rim, the tyre should be round. ....if you don't get it all on the bead seat, the tyre can have high and low spots
Pebble
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Re: Marathon plus tyre failure after puncture.

Post by Pebble »

the diameter of the wire will be the same if it is encased in the tyre or not. So surely you would still have the same problem getting the wire over the rim even if some had detached a little from the rubber.
thirdcrank
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Re: Marathon plus tyre failure after puncture.

Post by thirdcrank »

531colin

Thanks for the reassurance that I have not lost the plot completely.
pwa
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Re: Marathon plus tyre failure after puncture.

Post by pwa »

Pebble wrote: 1 Feb 2023, 9:31am the diameter of the wire will be the same if it is encased in the tyre or not. So surely you would still have the same problem getting the wire over the rim even if some had detached a little from the rubber.
Colin is saying that the wire in the bead is made up of a single strand that goes round a few times, but is not held in that position except by the rubber that is formed around it. So if the rubber doesn't grip it sufficiently, the strand can move and thus allow the hoop of wire to adopt a growing circumference.
simonhill
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Re: Marathon plus tyre failure after puncture.

Post by simonhill »

It is not a circle (loop) of wire with no opening. It is a continuous piece of wire wrapped around a few times.

Like thread on a bobbin, then secured (or not as in this case).
Kings Lynn dave
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Re: Marathon plus tyre failure after puncture.

Post by Kings Lynn dave »

I see pwa's point that you can't through the baby out with the bath water after one bad experience with a brand.
To be honest I have been looking for suitable tyres for my bakfeits cargo trike trike and the choice is slim. I need a heavy duty robust tyre that has size 26in 1.75. so the selection choice is low. I currently have a cheap one on that I bought from a local cycle shop on Sunday afternoon ( use bike for going to work and school run daily) . So I really need to think about changing it soon before I pick up another puncture.

If you guys are saying that it was a bad batch from 10 years ago how do you avoid getting a dud one again.? I can't remember were I got the tyre from, but it must have been a cycle dealer online, that I trusted. Otherwise I wouldn't of used them.
I guess the only way to avoid getting another one would be to buy from a large volume cycle shop such as Evans or Wiggle who buys direct from manufactures (rather than 3rd party dealers who your not sure hold old the stock is or were the stock comes from)
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531colin
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Re: Marathon plus tyre failure after puncture.

Post by 531colin »

The defective tyres I saw (2007 to 2012??) you could identify instantly, because the bead creaked when you flexed it......it doesn't normally do that.

Something else they did.....you would occasionally get a length of wire poking out from the bead.....more evidence it wasn't secured properly in the first place.
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531colin
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Re: Marathon plus tyre failure after puncture.

Post by 531colin »

Pebble
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Re: Marathon plus tyre failure after puncture.

Post by Pebble »

pwa wrote: 1 Feb 2023, 10:48am
Pebble wrote: 1 Feb 2023, 9:31am the diameter of the wire will be the same if it is encased in the tyre or not. So surely you would still have the same problem getting the wire over the rim even if some had detached a little from the rubber.
Colin is saying that the wire in the bead is made up of a single strand that goes round a few times, but is not held in that position except by the rubber that is formed around it. So if the rubber doesn't grip it sufficiently, the strand can move and thus allow the hoop of wire to adopt a growing circumference.
Indeed, but as one of those loops increased in diameter then another one would have to decrease, so yes it would go on easier but you would need to jiggle the loops about a bit so you were just putting the larger ones over the rim.

My thoughts looking at the earlier pictures is that the wire must have a break in it, probably happened when levering the tyre off, the wire must have then pulled through its rubber surroundings, thus allowing for the overall larger diameter. I suspect the broken two ends are probably 5 or 6 inches appart hence the greater dia.

How that has happened on both sides simultaneously remains a bit of a mystery. or one hell of a coincident.
Kings Lynn dave
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Re: Marathon plus tyre failure after puncture.

Post by Kings Lynn dave »

When I got my backfeits around 10 years a go it came with standard marathon tyres. These were fine for years. Last summer I had to respoke my back wheels in a shop and I decided to replace the old but still working tyre with the marathon plus ebike one. ( Recommended by all cargo bike shops I may add) when I bought it it had no sign of damage to the bead, and when I have had punctures in the autumn I never noticed any deterioration in the beads either. So it must have happened when I push the bike home on Friday.
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531colin
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Re: Marathon plus tyre failure after puncture.

Post by 531colin »

Pebble wrote: 1 Feb 2023, 6:12pm
Indeed, but as one of those loops increased in diameter then another one would have to decrease, so yes it would go on easier but you would need to jiggle the loops about a bit so you were just putting the larger ones over the rim.

My thoughts looking at the earlier pictures is that the wire must have a break in it, probably happened when levering the tyre off, the wire must have then pulled through its rubber surroundings, thus allowing for the overall larger diameter. I suspect the broken two ends are probably 5 or 6 inches appart hence the greater dia.

How that has happened on both sides simultaneously remains a bit of a mystery. or one hell of a coincident.
The most charitable thing I can say about this is its all completely wrong.

You don't need to invent a mysterious break in the bead wire. The wire is a long piece which does a few loops round the bead; all that holds it in place (and keeps its diameter constant) is embedding the wire in rubber. When the wire isn't properly set on rubber, its free to move and the bead diameter usually increases.

Occasionally you get the free end of the wire poking through the carcass. viewtopic.php?t=149177&hilit=wire+bead
Pebble
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Re: Marathon plus tyre failure after puncture.

Post by Pebble »

531colin wrote: 3 Feb 2023, 9:17am
Pebble wrote: 1 Feb 2023, 6:12pm
Indeed, but as one of those loops increased in diameter then another one would have to decrease, so yes it would go on easier but you would need to jiggle the loops about a bit so you were just putting the larger ones over the rim.

My thoughts looking at the earlier pictures is that the wire must have a break in it, probably happened when levering the tyre off, the wire must have then pulled through its rubber surroundings, thus allowing for the overall larger diameter. I suspect the broken two ends are probably 5 or 6 inches appart hence the greater dia.

How that has happened on both sides simultaneously remains a bit of a mystery. or one hell of a coincident.
The most charitable thing I can say about this is its all completely wrong.
that sort of heavily implies that you are very inclined to say something deeply unpleasant - why ?

I recall some tyres, much smaller tyres than a marathon plus and not from a bicycle, these had been incinerated on a bonfire, the wire that formed the bead was a closed loop, and not as you describe as a single length. So at least on that design of tyre the wire would need to have broken to create a larger dia..

Of course, if what you are saying is correct, in that the open ended coil of wire is just held in place by the rubber that is formed around it, then that could explain how both sides of the tyre could increase in dia at the same time, iif for instant the rubber was the wrong mix or temp when formed. On the design that I am aware of, the wire on both sides would have needed to snap.
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531colin
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Re: Marathon plus tyre failure after puncture.

Post by 531colin »

The rest of us are trying to have a discussion about a specific fault which occurs on Schwalbe bicycle tyres.
3 or 4 times you have derailed the thread with factually incorrect statements.......it turns out (after I lose my cool) that your expertise on the subject of Schwalbe bicycle tyres is based on something you found on somebody else's bonfire which you say were too small to be bicycle tyres.
Can you see that I might consider this unhelpful?
Pebble
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Re: Marathon plus tyre failure after puncture.

Post by Pebble »

531colin wrote: 3 Feb 2023, 12:19pm (after I lose my cool)
so were you shouting and jumping up and down ? - lol
the snail
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Re: Marathon plus tyre failure after puncture.

Post by the snail »

Pebble wrote: 3 Feb 2023, 9:38am the open ended coil of wire is just held in place by the rubber that is formed around it,
I don't think that is the case, the carcass of the tyre is wrapped around the bead, and it's the carcass that holds the tyre together, the rubber doesn't have much strength on it's own.
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