Schwalbe Marathon 700x32c - Failure/tear?? HELP!

theluggage · Post by **theluggage** » 1 Jun 2008, 12:27pm

Last year, I noticed that the rear tyre on our tandem had developed rips in the rubber just beyond where the rim meets the tyre. The tyre was still holding its shape OK & there were no other symptoms. Seeing this as a bit dodgy & unsafe I took it back to the local bike shop where I bought the tyres & they promptly gave a replacement, but no explanation.

I have just been checking the bike over before we go on holiday on it next week & I have noticed that the same thing has started happening to the front tyre. It has only done about 600 miles (it was bought at the time of the original back tyre) - no more than 2 years old.

I shall go through the things that I have thought of that maybe causing this & hopefully someone will be able to let me know what I am missing!

I have checked over the rims & neither seem sharp/ rough – where there was a slight edge where the rim was joined, did not correspond to any of the damage to the tyre. Also, the rims are fairly old – if they were the source of the problem, I would have thought it would have been noticed before now (the tandem I second hand – build in the 80s).

Tyre pressures – I normally inflate to 5/10 psi under the max – never higher. We have never ridden the bike on flat/ low tyres, nor has it been stored with flat tyres.

Heat – I keep a good eye on the temperature of the rims after long descents – to my knowledge, they have never got hotter than it is comfortable to hold my hand against. Also, had this been heat related, I would have expected the damage to be all around the tyres, not just in fairly small areas.

Anyways, here are some pics. More can be provided if necessary. I hope someone can shed some light on this…preferably before next weekend! :-)

Many thanks
Colin

Steve · Post by **Steve** » 1 Jun 2008, 5:58pm

We had exactly the same problem on our tandem a few years ago when the rear Marathon went bang. Since then I've avoided them although they are still popular with many tandemists. I've preferred Panaracer Paselas as they have have a textile anti-chafing strip (though I'm not sure the latest versions still do), and have never had this problem with them.

It may be that your tyre pressures are partly to blame though. You should keep the tyres on a tandem at the max stated pressure as a minimum - and even harder perhaps. That way the tyre sits more rigidly on the rim & is less prone to up & down movement of the sort which causes chafing & splits like this one.

theluggage · Post by **theluggage** » 1 Jun 2008, 6:15pm

Thanks for the reply Steve. Its good to know that it isnt just us! Needless to say if it turns out it is related to the design of the tyre, I shall be contacting schwalbe this time!
.

thirdcrank · Post by **thirdcrank** » 1 Jun 2008, 6:39pm

CTC Technical Q & A Scroll down to a Q & A on this problem.

(If you look at Schwalbe's PDF downloads - the current catalogue and the comprehensive technical info - they seem to make no claim or even mention of suitability for tandems.)

theluggage · Post by **theluggage** » 1 Jun 2008, 7:19pm

Thankyou for that link, very interesting - although it doesnt look like there is a miracle cure! I think I shall perhaps replace with 28s & give it a few extra squirts of air.

I shall investigate the tandem clubs website for any reccomendations....

Thanks Again.

Colin.

drossall · Post by **drossall** » 1 Jun 2008, 7:27pm

As a matter of principle, you should check that there is no chance of the edge of the brake blocks overlapping the rim and rubbing on the tyre, as this can damage the walls. However, it looks as though you have found a different explanation.

thirdcrank · Post by **thirdcrank** » 1 Jun 2008, 7:32pm

theluggage wrote: I think I shall perhaps replace with 28s & give it a few extra squirts of air.

What size are you using now? I'm no expert on modern tandems ( my old one had 26" wheels from the last time they were popular :oops:

) but I should have thought 35mm was the minimum for tandem touring?

theluggage · Post by **theluggage** » 1 Jun 2008, 7:51pm

We are using 32 at the moment - I think this is a fairly common size for tandem touring....I am going to quiz the tandem club website before I decide though - I am no expert either!

Thanks,

Colin

theluggage · Post by **theluggage** » 1 Jun 2008, 7:55pm

Drossal, thanks for the suggestion - I do indeed keep an eye on that. I think it is tyre pressure\width\make combination that seems to be offering the most likely cause at the moment.
cheers, Colin

thirdcrank · Post by **thirdcrank** » 1 Jun 2008, 8:20pm

sorry about the size question - as Les Dawson used to say in 'Blanketty blank' "The answer's in the question." :oops:

(And you are very civil not to alert me to my eyesight problem :roll:

)

theluggage · Post by **theluggage** » 1 Jun 2008, 8:33pm

No worries

reohn2 · Post by **reohn2** » 1 Jun 2008, 10:06pm

We've been using Schwalbe Marathons for about 5yrs on both tandems and I use them on solo,we've never had a problem with them.
In 700cx32mm I inflate to 85/87psi for day rides,in 559x40mm inflate to 82/85psi when carrying any weight ie two rear panniers +rack pack I increase presures by 5psi.

If you've lost confidence in Schwalbes try Vredestein Perfects they are also a good tyre IMO but wear out quicker due to a softer compound.

Auchmill · Post by **Auchmill** » 2 Jun 2008, 8:49am

I don't buy the "brand X is no good because I've had a problem" thesis. Unless there's a manufacturing fault on a batch applying to everybody then it's likely to be "operator error". Seems to me under-inflation has been identified as the likely cause. I suspect under- is more problematic than over-inflation. A guy from Schwalbe recommended 100psi when riding a loaded tandem on Marathons. You also need an accurate tyre pressure gauge. I check my track pump's gauge against a good car gauge.

Paul Smith SRCC · Post by **Paul Smith SRCC** » 2 Jun 2008, 9:38am

Steve wrote:... It may be that your tyre pressures are partly to blame though. You should keep the tyres on a tandem at the max stated pressure as a minimum - and even harder perhaps. That way the tyre sits more rigidly on the rim & is less prone to up & down movement of the sort which causes chafing & splits like this one.

I would second that, the Schwalbe Marathon has been the most reliable tyre I have ever stocked, to have two fail in exactly the same way would indicate that something is causing it, under inflation especially on a Tandem could indeed be a possible cause

Paul_Smith
www.bikeplus.co.uk

drossall · Post by **drossall** » 2 Jun 2008, 6:34pm

I've just remembered that I did, last year, have a Marathon fail on the side wall like that when nearly new. I took it back and the shop (SJS) accepted immediately that it was a dud, probably from a bad batch, and swapped it.

It wouldn't stop me using Marathons though - in fact I bought five more while I was there