Tyre trouble

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martinn
Posts: 299
Joined: 1 Dec 2012, 8:20pm

Tyre trouble

Postby martinn » 2 Feb 2019, 9:24pm

Hi all

I put my Marathon winters on for the snow and ice. These were on a wide rim designed for tires up to 42mm 700c. These are 35x 700c. they have been fine for the last three days
On the way home tonight, the rear felt "Odd" i stopped and noticed that the tire had popped out of the rim, so deflated the tire completely and reset the tire and reinflated. This went on for a few repeats, varying the pressure, taking the tire off re-seating etc, until finally i got bored with the whole thing!

no matter what I did the tire still came off the rim.

What could be the problem?

Many thanks

Martin

Brucey
Posts: 33872
Joined: 4 Jan 2012, 6:25pm

Re: Tyre trouble

Postby Brucey » 2 Feb 2019, 9:28pm

what exact rim is this? What pressure were you running? when were the tyres made?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

martinn
Posts: 299
Joined: 1 Dec 2012, 8:20pm

Re: Tyre trouble

Postby martinn » 2 Feb 2019, 9:48pm

rims -Fulcrum R700 DB
tire pressure varied between very low sub 30psi to around 75PSI

Cheap deal from Spa about 4 years ago

Brucey
Posts: 33872
Joined: 4 Jan 2012, 6:25pm

Re: Tyre trouble

Postby Brucey » 2 Feb 2019, 10:29pm

there's at least three things that could be making a difference

a) they are tubeless compatible rims; a lot of these seem to have smaller lips than rims for tubed tyres
b) the tyres were manufactured during a period when Schwalbe tyres often came with the bead wires not infiltrated with rubber
c) running at low pressures 'helps the tyre off the rim' esp if b) applies


You can usually tell if the tyres have bead wires that are not infiltrated with rubber because the tyre creaks when you flex it. Affected tyres can be come so loose that they won't work on any rim and/or the bead wire starts to poke out of the tyre structure. Affected tyres can also work Ok if they are kept hard; this keeps the beads from moving around and working loose. Once the tyres are 'stretched' (I.e. the beads have moved) they are usually rendered useless.

However I have also seen tyres that blew off tubeless compatible rims yet the same tyres were just fine when fitted on a conventional rim.

So I'd suggest that you try the same tyres on different rims and see how you go.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

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RickH
Posts: 4288
Joined: 5 Mar 2012, 6:39pm
Location: Horwich, Lancs.

Re: Tyre trouble

Postby RickH » 3 Feb 2019, 7:30pm

I bought some Schwalbe Snow Studs some time in 2017 (in a Planet X sale). When I first fitted them one started peeling off the rim after about 3 miles from new & wouldn't stay on. One of the beads had failed (stretched/broken I don't know which).

The single bead that failed simply became too big a circumference to stay on the rim. Once it had started coming off it was completely impossible to get it to stay on - it would be off again withing a couple of turn of the wheel. The other side wasn't a problem.

The tyre was replaced FOC (promptly) & the one that I kept and the replacement have both been fine (beads all fit tightly but not too tightly that they are a struggle to get on & off).

martinn
Posts: 299
Joined: 1 Dec 2012, 8:20pm

Re: Tyre trouble

Postby martinn » 6 Feb 2019, 9:10pm

Thanks all,

I looked at the tires, the side that was coming off is definitely a different shape to the other side, so I am assuming that the bead has broken/ come adrift,

many thanks

Martin

Marcus Aurelius
Posts: 371
Joined: 1 Feb 2018, 10:20am

Re: Tyre trouble

Postby Marcus Aurelius » 6 Feb 2019, 9:27pm

The rim is probably worn down at the braking surface, as they get thinner, they get weaker.

martinn
Posts: 299
Joined: 1 Dec 2012, 8:20pm

Re: Tyre trouble

Postby martinn » 6 Feb 2019, 9:47pm

I can see where your coming from, but not in this case, as the wheels are disc braked

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RickH
Posts: 4288
Joined: 5 Mar 2012, 6:39pm
Location: Horwich, Lancs.

Re: Tyre trouble

Postby RickH » 6 Feb 2019, 10:25pm

martinn wrote:Thanks all,

I looked at the tires, the side that was coming off is definitely a different shape to the other side, so I am assuming that the bead has broken/ come adrift,

many thanks

Martin

That's what I found.

Once off the rim the tyre no longer had a symmetrical U shaped cross-section but flared out on the side that was peeling off.