TYRE PRESSURES

General cycling advice ( NOT technical ! )
pootler
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TYRE PRESSURES

Postby pootler » 21 Apr 2013, 8:04pm

On checking over my bike this morning I noticed some cracking to the walls of my rear Schwalbe Marathon tyre. On their website they say that the new marathons are constructed to avoid the problem of damage to the sidewalls caused by under inflation. How hard do they have to be? Is it essential to use a track pump?

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Mr. Viking
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Re: TYRE PRESSURES

Postby Mr. Viking » 21 Apr 2013, 9:06pm

Well if that is their wording you probably should pursue a refund or a replacement from whomever you bought it from. Sidewalls can also crack as rubber degrades with age, but as these are supposed to be heavy duty, low maintenance one might imagine this would take longer than usual. How old are the tyres?

As for correct pressure, it depends on the width of the tyre. If it is a narrow road tyre you would need a track pump to get enough pressure in, and a pressure gauge to tell the correct pressure. If it is a chunky off road tyre, the required pressure is substantially lower and can be maintained with cheaper pumps, and it is easier to tell if the tyre is at the correct pressure

reohn2
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Re: TYRE PRESSURES

Postby reohn2 » 21 Apr 2013, 9:56pm

For correct TP's :- http://www.bikequarterly.com/images/TireDrop.pdf

and for some further reading :- viewtopic.php?f=5&t=74913

How bad are is the cracking,I've HS308 and 368's sometime develop small cracks but have never found them to compromise the structure of the tyre even on the tandems.
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ukdodger
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Re: TYRE PRESSURES

Postby ukdodger » 21 Apr 2013, 11:22pm

pootler wrote:On checking over my bike this morning I noticed some cracking to the walls of my rear Schwalbe Marathon tyre. On their website they say that the new marathons are constructed to avoid the problem of damage to the sidewalls caused by under inflation. How hard do they have to be? Is it essential to use a track pump?



Hmmm. They say 'caused by under inflation'. Are your tyres Marathon plus with that Kevlar belt in them? If so I'd wager that is the reason for sidewall cracking. It happened to a pair of mine with cracks appearing all the way around on both tyres. I complained to Schwalbe sending them pics of the tyres and they sent me two new ones so they must have been aware of the problem and I didnt ride them under inflated. The Kevlar is harder and stronger than the rubber of the sidewalls and they crack at the join. That was two years ago.

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531colin
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Re: TYRE PRESSURES

Postby 531colin » 22 Apr 2013, 7:30am

Marathon plus have a thick layer of rubbery stuff under the tread, which makes the carcase very stiff (and the tyres a very wooden ride)

Regular Marathon had a Kevlar belt until just recently, now Schwalbe put some rubbery stuff under the tread on them, too....the new "greenguard"

............http://www.schwalbe.co.uk/tour/

ukdodger
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Re: TYRE PRESSURES

Postby ukdodger » 22 Apr 2013, 10:51am

531colin wrote:Marathon plus have a thick layer of rubbery stuff under the tread, which makes the carcase very stiff (and the tyres a very wooden ride)

Regular Marathon had a Kevlar belt until just recently, now Schwalbe put some rubbery stuff under the tread on them, too....the new "greenguard"

............http://www.schwalbe.co.uk/tour/


I like Schwalbe tyres but I wish they'd stop buggering about with them.

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531colin
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Re: TYRE PRESSURES

Postby 531colin » 22 Apr 2013, 1:40pm

After I posted the link to Schwalbe website, I Emailed them to put cutaway drawings of the tyres on their website....so much clearer than all the blurb. and they supply cutaway tyres to the shops for demonstration!
but the Marathon has been Kevlar for years (and at least 2 tread patterns) and the Marathon plus has had the rubbery stuff for years (and at least 2 tread patterns)....its only in the last few months that they put the rubbery stuff in the marathons....needlessly, in my view.

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531colin
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Re: TYRE PRESSURES

Postby 531colin » 22 Apr 2013, 1:44pm

pootler wrote:On checking over my bike this morning I noticed some cracking to the walls of my rear Schwalbe Marathon tyre. On their website they say that the new marathons are constructed to avoid the problem of damage to the sidewalls caused by under inflation. How hard do they have to be? Is it essential to use a track pump?


A photo would be really useful......tyre pressure depends on your weight and the tyre size.
I don't think a track pump is essential.....otherwise how would you deal with a puncture when you are out?......but after you have used one, you won't be without one!

ANTONISH
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Re: TYRE PRESSURES

Postby ANTONISH » 22 Apr 2013, 2:01pm

I think track pump would come under the heading "nice to have".
My Zefal HPX frame pump will deliver over 110 psi quite comfortably. Some of us remember the days of riding to the start of a road race and having to put in sufficient pressure to satisfy the bike checker- that could be quite hard work with the old style frame pump.
I note that many cyclist's these days possess a track pump and one of these next to useless mini toys for when they actually have to inflate a tyre on the road. I know some of them work but I often find myself helping with inflation when time is pressing.

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andrew_s
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Re: TYRE PRESSURES

Postby andrew_s » 23 Apr 2013, 12:00am

ANTONISH wrote:I know some of them [mini pumps] work but I often find myself helping with inflation when time is pressing.

Likewise. Even if time isn't pressing, I often hand over my HPx so I don't have to hang around getting cold for so long.

Even if the mini pump is a good one, the number of pump strokes at at least proportional to the pump volume, so you are looking at about 4 times as many pump strokes to get up to pressure. Any dead air space is a higher proportion of volume as well, so it could be substantially worse than that.

reohn2
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Re: TYRE PRESSURES

Postby reohn2 » 23 Apr 2013, 7:31am

ukdodger wrote:
531colin wrote:Marathon plus have a thick layer of rubbery stuff under the tread, which makes the carcase very stiff (and the tyres a very wooden ride)

Regular Marathon had a Kevlar belt until just recently, now Schwalbe put some rubbery stuff under the tread on them, too....the new "greenguard"

............http://www.schwalbe.co.uk/tour/


I like Schwalbe tyres but I wish they'd stop buggering about with them.

Agreed.
There are ten different Marathon types :shock: Just check how many of those overlap yet aren't available in enough sizes.Frustrating,ie;I'd like to see their Kojak tyre in at least five 700c sizes as it's only available in one,thankfully it's a size I use ,700x35 (though measures 32mm on a touring rim),IMO they'd sell very in 25,28,32and37mm sizes.
I don't know who uses 700x25 and 28 M+ but their dentist would be rubbing his hands :shock:
I'd also like to know what their M/Supreme is all about :?
As for Green Guard Marathon goes they can have it,by far the best Marathon made was the H308 a good roller on tarmac,great for rough stuffing and lasted,the H368, didn't last and on mucky tracks paled by comparison.
They also now make a Dureme tandem tyre available in one 700c and one 26in size pointless :?
The Racer is a good road/mild offroad tyre but why have they chaanged the tread pattern? :?
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ukdodger
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Re: TYRE PRESSURES

Postby ukdodger » 23 Apr 2013, 12:48pm

reohn2 wrote:
ukdodger wrote:
531colin wrote:Marathon plus have a thick layer of rubbery stuff under the tread, which makes the carcase very stiff (and the tyres a very wooden ride)

Regular Marathon had a Kevlar belt until just recently, now Schwalbe put some rubbery stuff under the tread on them, too....the new "greenguard"

............http://www.schwalbe.co.uk/tour/


I like Schwalbe tyres but I wish they'd stop buggering about with them.

Agreed.
There are ten different Marathon types :shock: Just check how many of those overlap yet aren't available in enough sizes.Frustrating,ie;I'd like to see their Kojak tyre in at least five 700c sizes as it's only available in one,thankfully it's a size I use ,700x35 (though measures 32mm on a touring rim),IMO they'd sell very in 25,28,32and37mm sizes.
I don't know who uses 700x25 and 28 M+ but their dentist would be rubbing his hands :shock:
I'd also like to know what their M/Supreme is all about :?
As for Green Guard Marathon goes they can have it,by far the best Marathon made was the H308 a good roller on tarmac,great for rough stuffing and lasted,the H368, didn't last and on mucky tracks paled by comparison.
They also now make a Dureme tandem tyre available in one 700c and one 26in size pointless :?
The Racer is a good road/mild offroad tyre but why have they chaanged the tread pattern? :?


Yes that says it all. I'd like ordinary Marathon in 700x38 but you have to have that size in Plus which as has been said rides a bit wooden.

R2 in another thread (cant be bothered to look it up) you said we'd both bought the same patches of off Ebay. They were a lot (maybe 50) for only £1.98 I think. Well I've used six of them and they all came off. So I binned the rest. Did you have the same experience?

pootler
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Re: TYRE PRESSURES

Postby pootler » 23 Apr 2013, 1:55pm

Thinks to myself, there is more to this tyre malarky than meets the eye. Talking about eyes I put my glasses on and hey presto, in small writing I found that tyre pressures between 4.4 bar/ 55lbps and 6.6 bar / 95 lbps are recommended on the tyre wall. Someone did ask about my tyre size and personal weight, so here goes. 700x32 and 14.5 stone. :oops: and in less than 2 weeks I'm touring in the Jura with my daughter. She might have to wait for me on the odd occasion!

samsbike
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Re: TYRE PRESSURES

Postby samsbike » 23 Apr 2013, 3:59pm

reohn2 wrote:
ukdodger wrote:
531colin wrote:Marathon plus have a thick layer of rubbery stuff under the tread, which makes the carcase very stiff (and the tyres a very wooden ride)

Regular Marathon had a Kevlar belt until just recently, now Schwalbe put some rubbery stuff under the tread on them, too....the new "greenguard"

............http://www.schwalbe.co.uk/tour/


I like Schwalbe tyres but I wish they'd stop buggering about with them.

Agreed.
There are ten different Marathon types :shock: Just check how many of those overlap yet aren't available in enough sizes.Frustrating,ie;I'd like to see their Kojak tyre in at least five 700c sizes as it's only available in one,thankfully it's a size I use ,700x35 (though measures 32mm on a touring rim),IMO they'd sell very in 25,28,32and37mm sizes.
I don't know who uses 700x25 and 28 M+ but their dentist would be rubbing his hands :shock:
I'd also like to know what their M/Supreme is all about :?
As for Green Guard Marathon goes they can have it,by far the best Marathon made was the H308 a good roller on tarmac,great for rough stuffing and lasted,the H368, didn't last and on mucky tracks paled by comparison.
They also now make a Dureme tandem tyre available in one 700c and one 26in size pointless :?
The Racer is a good road/mild offroad tyre but why have they chaanged the tread pattern? :?



I use the M+ in a 25 and yep its a firm ride but then I dont have anything to compare it too.

I run mine at 110 based upon the bikequarterly reference and do get bounced out of the saddle on occassion.

I need to see what the biggest size I can run with my bike, but thats a thread for another day!

reohn2
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Re: TYRE PRESSURES

Postby reohn2 » 23 Apr 2013, 4:02pm

ukdodger wrote:
R2 in another thread (cant be bothered to look it up) you said we'd both bought the same patches of off Ebay. They were a lot (maybe 50) for only £1.98 I think. Well I've used six of them and they all came off. So I binned the rest. Did you have the same experience?


I don't think I've used any yet,but I'll doing some tests shortly :?
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