Thorn Cycles Forum
Technical => Wheels, Tyres and Brakes => Topic started by: Matt2matt2002 on January 14, 2013, 08:35:05 pm
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I have been running a pair of Schwalbe Marathon Plus babies on my Dawes Sardar tourer.
One puncture in the last 1,500 miles.
Tred depth is the question.
Should I measure it and if so what depth is safe?
They look like they could easily go another 500+ miles
My riding is 95% of the time unloaded on tarmac roads
Thanks folks
Matt
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Hi Matt!
On their website, Schwalbe say their tires can be run till the blue under-belting shows through the tread...In bicycle tires the tread is far less important than for instance in car tires. So using a tire with a worn out tread is less of a problem, that is of course with the exception of MTB tires.
When the puncture protection belt or the carcass threads can be seen through the tread the tire has reached its wear limit and must be replaced. As the puncture resistance also depends on the thickness of the tread layer it may be useful to replace the tire earlier.
The sidewalls of tires often fail before the tread is worn out. In most cases, this premature failure is due to prolonged use of the tire with insufficient inflation pressure. Checking and adjusting the inflation pressure at least once a month with a pressure gauge is most important.
From: http://www.schwalbetires.com/tech_info/tire_wear
Best,
Dan.
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Jeezo!
And I had looked at the Schwalbe site myself 10 mins ago.
::)
Ok - lets broaden this sucker out.
Whats an expected mileage I can expect?
Given average pressure, tarmac and unloaded riding.
Please don't tell me that's on their web page?
;)
Matt - who is obviously not tired of this question
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Whats an expected mileage I can expect?
Hi Matt!
I'm not sure this is answerable in quantifiable terms. As the tire wears, the contact surface area broadens (less tread = more slick) which should actually reduce the rate of wear. However, carbon black is highly wear-resistant, and once you wear through that into the "blue" underlayer (which is more pliable but less wear-resistant), the rate of wear should increase.
Jobst Brandt proved long ago (with Avocet tires) that tread does *not* help wet-road traction (in other words, a bicycle is not subject to hydroplaning in the same way as a car), so if your use is on pavement, and unloaded, you should be able to safely use the tires as Schwalbe recommend. I'm guessing, however, that you'll be come subject to more flats as the tread thins and becomes less subject to penetration by sharp objects.
I'd run 'em till I started getting more frequent flats, then retire 'em and get new. If I were going on-tour, I'd buy and mount new ones before departure.
My two cents, adjusted for inflation.
Dan. (...who, likewise, never um, "tires" of this topic ;) )
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The reason Schwalbe says until blue starts showing through is probably because they don't want you to run the tyre until it is all blue on the tread surface. The grey bits of the tyre have a different constitution to the blue bits of the protection rubber, and the handling characteristics may change. It may even be dangerous to ride on the blue. What is certain is that the blue rubber will wear very fast, because it lacks the carbon in the grey outer.
I run Schwalbe Big Apple Liteskins, and I have one getting thin, so I'll run it till the top surface wears through to see what happens. Don't forget to report here if you discover before I do.
Andre Jute
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don't think i would fancy riding a well worn tire on wet roads ::)
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Thanks folks.
That point about tread and hyrdoplaning rang a bell with me.
I was amazed to see some of the motorcycle tyres in my area with little or no tread.
Could you give me a link for the info?
Matt
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Here ya go, Matt; this one falls readily to my typing fingers, so gets forwarded first:
http://sheldonbrown.com/brandt/slicks.html
Best,
Dan.
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...and a whole, entire related thread from the Good/bad ol' days of USENET, here:
http://yarchive.net/bike/slicks.html
Best,
Dan.
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By golly, I miss Jobst Brandt, probably the finest (and among the handful of most distinguished -- Formula 1 cars still stop on brakes he designed for Porsche more than half a century ago) engineering mind to be turned to cycling in our time. And Ken Kifer, who makes a cameo appearance, who influenced me enormously in my statistical approach to bicycle safety, component choice, etc; I chose Andy Blance after Ken was killed by a drunk driver, because he had the same pragmatic approach.
Andre Jute
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From the Schwalbe North America website : http://www.schwalbetires.com/tech_info/tire_wear
Marathon Plus quoted expected mileage of between 8000km and 15000km.
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By golly, I miss Jobst Brandt...
Me, too. Andre...have you any word about how Jobst is doing -- long-term -- after his accident: http://search.bikelist.org/beta/TreeView.aspx?id=443462 That's nearly two years old. This update posted October 2011 sounded encouraging: https://groups.google.com/forum/?fromgroups=#!topic/rec.bicycles.tech/hnhG5WjRKSY (with your 2 cents' worth added).
By any chance, do you know if he was able to get back on a bike?
All the best,
Dan.
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No, he's not riding. I'm not aware of any more reliable news than that he's out of hospital, at home, lucid and receiving visitors. -- AJ
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Marathon Plus quoted expected mileage of between 8000km and 15000km.
This would be pretty correct. I've been getting 12000 - 15000kms from my Vittoria Randonneur Cross tyres, a similar highly durable touring tyre with high-level puncture protection.
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See Jeff Kruys's Schwalbe experiences, in the "Fun, Facts and Figures" sections of his trip journal:
http://www.crazyguyonabike.com/doc/page/?o=1r4vFZo&page_id=81957&v=2Ok (http://www.crazyguyonabike.com/doc/page/?o=1r4vFZo&page_id=81957&v=2Ok)
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Moral of the stroy looks like if you want a tyre that lasts hen get a Schwalbe Marathon Plus- If only they were nice to ride - lol
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Well, I am happy with them.
However......
Last week while out on my usual 40 miler around the sunny lanes of South West Scotlandshire ;)
I noticed a soft flappy kinda sound from the front wheel. It was regular and I tracked it down to a wee slither of rubber that had started to come away from the side wall.
I tried to photograph it but my camera is not up to close up work.
I would say it is about 7 mm long and 2 or 3 mm wide.
On every revolution it hits the side of my brake pad with a soft flap sound.
It appears quite a regular shape so do not suspect a damaged cut cause. But am ready to be corrected.
I have not yet sliced it off.
May I seek advice here please?
By the way.
I had a similar incident when a clear flap of cellophane that covered the wording of Marthon started to come away from the tyre. This was easy to pull off not being part of the rubber.
Trust no one is tired of this thread yet?
:D
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Trust no one is tired of this thread yet?
"Never for me", says Dan, who is seeking any excuse to delay hefting his 116lb kitchen stove into place. The problem is not "weight" but "width" it is a long reach from side to side. This is a better excuse than most.
Matt, I always toss a bottle of beta-cyanoacrylate "super glue" into my tool kit when touring and sometimes I carry one in my underseat bag on day rides as well. The "beta" kind will also glue woods, leather, and rubber, and works extremely well for tacking down little rubber tags where the belted underlay is intact and um, "integrous". In a pinch, I have also used it for instant tube repair (squeeze the tube sides till the hole opens, put a drop of beta-cyano in, wait 10 seconds and install and reinflate. Good to go; I've never had a failure of a "glue patch" of this sort and it is about as fast as a glueless patch. When I have run over a nail or some such, I squeeze the tire casing and put a drop in the opened hole as well. I think this keeps water and such from penetrating the hole to the interior of the tire.
I also use this glue to glue-in my tire boots when it comes to that, stitching around with a thin bead, then slapping in the boot. Keeps them from shifting. The glue is also a very nice substitute for sutures when you manage to open a sizable cut and lack the needle and thread to do proper sutures one-handed. Just get the wound adequate clean and disinfected before tacking it together with the glue. The glue also works great for blister prevention, as it bonds to skin. When you get a "hot spot", spread on a drop and smear it around with the bottle tip, then let it dry. There's a million and one uses for the stuff. Just don't get it in your eyes, as it stings like fire but is eventually (and amazingly!) harmless. Don't ask how I know this. ::)
If the underlying belt on your tire looks good, I'd be inclined to tack down that little rubber flap with a dab of beta-cyano and keep watch on it. It might not be a structural problem.
Best,
Dan. (...who is "careful" with money and thinks "flappity-flappity" might not be as bad as it sounds)
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Thanks Dan
I was holding off of the glue solution until advised as suitable.
I do stock super glue in my shop to will try out a tube tomorrow and report back.
The last time I used a tube I managed to glue 2 of my fingers together. So i am now extra careful when using the stuff.
The solution to my 2 finger delema was to use a scalpel to divide the fingers. Even with great care I still managed to wander by a millimetre or so. Not a pretty site!
Regarding your suture solution. Is there a substance to dissolve the glue or does it just fade away as the wounds heal?
Matt
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...The solution to my 2 finger delema was to use a scalpel to divide the fingers. Even with great care I still managed to wander by a millimetre or so. Not a pretty site!
Regarding your suture solution. Is there a substance to dissolve the glue or does it just fade away as the wounds heal?
Yep; on wounds, the glue just sort of fades away over time. I think the skin oils cause it to lift from below and then it cracks off. It is a nice way to hold raw edges together for things like cuts, not good for scrapes. It also works to keep Steri-Strips in place to bridge the edges without getting glue in the actual cut. A much better use of the glue.
Real Cautions Ahead...
The real problem is you don't want to seal bacteria inside or you'll have Real Problems® develop shortly. I consider it a remedy of last resort when a person really needs a stitch or three and none are available and (in the case of a hand) only one hand is available and you don't have one hand free to hold the edges together while you stitch with the other. Of course, my hands and forearms already look like I've worked in a glass factory due to the evidence (scars) of an active mechanic's/DIYer's lifestyle and lots of past suture "train tracks".
I don't want to be too cavalier about this and have it mistakenly appear I am encouraging people to grab a bottle of SuperGlue and play Field Surgeon. If one has sliced oneself sufficiently to require stitches, then it is a Really Good Idea to go to a doctor or A&E and get some. Punctures require a tetanus shot as well. It is Dirty out in the field, and hard to irrigate and cleanse a wound properly, especially when by oneself and the only water available is what remains in your bottle and the bottom third or so is half spit. What I've gotten away with after midnight in my garage/shop while deep in the middle of a project and reluctant to take the time to drive to the A&E and can always get checked by a doctor the next morning...is a Not-Good Idea in the field. However, sometimes when touring I'm a long, long way from anyone, and buying another day or so by gluing a slice shut sure beats leaving a trail as I pedal out.
As to removing SuperGlue, there are special removers marketed just for that, but non-acetone nail polish/nail varnish remover will do the job with patience and gentle rocking side-to-side of the skin edges, as if rolling one glued finger against the other. Soaking in warm water till your fingers wrinkle and get pruney and then gently rocking from side-to-side will do the job eventually as well and even olive oil will start the process in a pinch. The thing you don't want to do is try to pull your fingers directly apart. The skin surface will stay bonded and come loose form the deeper layers, leaving a gap beneath much like when a blister cover rolls off -- ouch!
If you try gluing your tire, be sure you use the beta-cyanoacrylate, Matt. This is the stuff that promises to glue leather and wood and rubber and such and says so right on the tube label. The regular stuff won't work well with rubbery items and will give poor results.
Hope this helps.
All the best,
Dan. (...who is out of well-meant cautions for the moment)
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Replaced my rear tyre which was supplied new with the bike, the bike is just over one year old.
The tyre was a Conti Contactsport 26x1.6in and had a two inch bald patch which caused my second puncture since new. Estimated mileage before failure of around 4,000 miles - feels a bit on the low side to me, although I have a reasonably hilly commute with occasional heavy braking.
The front tyre seems OK.
The tyres being quite slick I have had one departure from controlled cycling in an incident with wet leaves, but otherwise I enjoy the way they ride.
Whenever I have a puncture/tyre failure I always have to google re attaching the Alfine 8 procedure and re train myself!
Moral of the story check my tyres more carefully before setting off, and make a note of the Alfine 8 process and keep it with the puncture kit.
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dan how come i've gone to guest status :o
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Anto!
Your status is still Hero Member (again; you were there once before, cancelled the account, then rebuilt back to the magic 1,000 posts for Hero).
Your login shows as "guest" 'cos your browser has cleared the cookies necessary to stay logged in /or/ you signed in initially for a set period that has now expired. To sign back in as a member (and see photos as a perk!), just re-enter your username and password in the upper-left corner of the screen and all should be well.
Please let me know if you still have problems.
All the best,
Dan.
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hah i thought for a moment i got the sack ;D ;D