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Post by team-art on Nov 25, 2011 9:57:17 GMT
Panties pressed. Has anybody got a 16 x 1.75 (47-305) Schwalbe Marathon they can measure?
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Post by andy on Nov 25, 2011 10:07:58 GMT
Panties pressed. Has anybody got a 16 x 1.75 (47-305) Schwalbe Marathon they can measure? I have some ordered
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Post by Scottish Cartie Association on Nov 25, 2011 10:30:56 GMT
"Fit for purpose" is not a term that can be objectively assessed in the ~9 minute per cartie that we have for scrutineering. "Less than or equal to 584mm" is.
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Post by kingkay on Nov 25, 2011 11:11:27 GMT
I can only speak for myself but knickers are big and lacy, they tangle easily. Our tyres were pretty knackered before we got to Dalby. They were knackered by Cairngorm the year before ;D. By the end of Dalby we had two tyres held together with gaffer tape. One was put due to the cart in front coming off the tow eye going up the hill and as we repeatedly rammed it a sharp bit ripped the tyre. Nothing much could be done about that. We blame the gimp doing the towing. Luckily the powers that be have addressed the towing issues (thankyouverymuch). Let’s hope that helps. The other gaffer taped wheel was caused by Stocker pulling a 4 second skid coming over the bridge at the finish line. It burnt right through. Your point is taken – massive skids shag tyres, we all grasp that. But can you tell us categorically that just because a tyre is wider that the rubber is any thicker? From my understanding the cloth weave inside tyres is generally much stronger/thicker on skinny tyres because they’re designed to go fast and suffer more stresses accordingly. I know loads of wide tyres are thicker, but they’re not the ones people are going to choose to race with, they’ll be going for the light, slick and therefore thin rubber ones whether they’re 28mm or 58mm wide. Slightly bigger contact area I know but will it make that much difference? If I get to anything like 70 mph I’d much rather be doing it on a tyre designed for the job. “ The effect of wider and heavier tyres is on speed is not huge, but the physics is clear even if peoples' understanding of it isn't. “ I think most people who can be bothered to build a cart have a pretty reasonable grasp of the physics involved. Thats why we're all going for the slick skinny's. Although I always wondered why Lance Armstrong doesn’t do the Tour de France on a beach cruiser. “ The main concern is that the light and skinny stelvios, kojaks, etc that are becoming increasingly popular are just too fragile for Cairngorm. You need to brake very hard before the Switch and if you lock up your wheels you will burn through them in about two seconds. Even if you don't shred them instantly, you'll have severely weakened them.” But it would probably be at 35mph not 70mph where your fat crap tyres might let you down. I get your point, and in all honestly I can say having used them that stelvios pumped up to 120 psi are twitchy as hell, extremely bone jarring and I wouldn’t use them again for Cairngorm - I'd go for something a little bit fatter with a bit more give/grip, but equally I don’t think changing to standard BMX tyres is any better or safer, and I think the point at which they might let you down is likely to be a lot more serious.
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Post by kingkay on Nov 25, 2011 11:15:40 GMT
Andy, pump them up and if they're too small don't panic for 24hrs!!
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Post by andy on Nov 25, 2011 11:28:58 GMT
I'm on it !
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Post by Organgrinder on Nov 25, 2011 21:05:59 GMT
we don't want to make it prohibitively difficult for you to find tyres, so we'll be releasing a new version of the rules in the next few days which reduces the minimum width for all wheel sizes to 44mm.Power to the people!!
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Post by grahamk on Nov 25, 2011 22:04:09 GMT
Ohh good, that's another £40 i have just wasted on tyres, never mind another £64 for slightly skinnier ones.
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Post by Scottish Cartie Association on Nov 26, 2011 1:32:04 GMT
F*** me you lot are hard to please
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Post by grahamk on Nov 26, 2011 10:18:22 GMT
They will come in handy Maybe add some flowers and make a winners wreith. ;D
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Post by brillo451 on Nov 26, 2011 15:24:47 GMT
If only there was a LIKE button on this forum I would have pressed it for the last post... LOL
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Post by team-art on Nov 26, 2011 16:05:58 GMT
What’s the current 406 weapon of choice? Or is that confidential information?
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Post by Scottish Cartie Association on Nov 26, 2011 16:59:12 GMT
Schwalbe Mad Mikes
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Post by leew on Nov 26, 2011 17:14:14 GMT
If you want the fastest 406 tyre in terms of rolling resistance then go for the Vredestein GoCycle Performance tyre. www.evanscycles.com/products/gocycle/performance-tyre-ec022745A mate did roll down tests with a large number of tyres, including skinny tyres like the kojak and durano and the GoCycle went the furthest. The tests were at low speed to reduce the effect of air drag. At high speeds the narrower tyres will most likley be faster due to air resistance however if you are putting your number plates vertically infront of the front wheels then the width will make little diffrence.
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Post by team-art on Nov 26, 2011 19:27:36 GMT
Hi Lee, Vredestein GoCycle Performance tyre. Folding tyre, any idea of the weight?, Enough @ £30, looks the part!
if you are putting your number plates vertically in front of the front wheels …That’s the first place I’d want to test
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Post by team-art on Nov 26, 2011 20:05:16 GMT
Mad Mikes......Perhaps Schwalbe could add to the range, make your own up as required. Svelte Stephen Careless Colin Amiable Andy Reckless Roy Grumpy Graham Terse Toby Pickled Peter Comatose Charlie …… Ridiculous Rich
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Post by leew on Nov 26, 2011 20:34:12 GMT
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Post by Scottish Cartie Association on Nov 26, 2011 22:22:43 GMT
That sounds worryingly light to me. If you're planning to use tyres that light, then make sure you test them thoroughly before you come to Cairngorm, and also make sure you bring some alternatives as well.
It would be extremely stupid if the Switch were the first corner you try to take on them.
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Post by azuma on Nov 26, 2011 22:25:25 GMT
Lee, are these not a folding tyre, which will not be wire beaded, which I think are not allowed as well??
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Post by leew on Nov 26, 2011 22:40:30 GMT
There is nothing in the rules prohibiting lightweight or folding tyres. Only restrictions i can see are on overall size or width. I used two sets of duranos to go down a few hundered hills, some over 10 miles long and 2000' in drop while in the USA earlier in the year. They were not new when I started though, starting with a new set I may have been able to do it with just one set. I reached speeds over 70mph too.
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