I need a set of fast rolling, thinner tyres for my ice sprint,at the moment i've got marathon racers on at 1.5.I'm looking at the schwable duranno, but the tyre widths are totally foreign to me especally as i've got 26" rear, they all seem to be diffrent sizes, eg a 26x1.3 and a 20x11/8.Can anyone help, i was looking at a 25mm or 28mm tyre

1 inch = 25.4mm. So a 1.3 inch tyre is approx' 33mm and 1 1/8" is about 28.6mm.

"I thought of that while riding my bike." --Albert Einstein, on the Theory of Relativity

2007 ICE QNT
2008 Hase Kettwiesel AL27
2011 Catrike Trail.
1951 Engine in need of partial rebuild.

Yeah, that is why we use the ERTRO sizing... There are (at least) two fairly common 16in, 20in, etc. sizes and they're all mutually incompatible. I did have a look up table with around 40 different bike wheel/tyre size descriptions...

A 20x1 1/8 *SHOULD* be a 451mm bead tyre, tho I've seen Continental incorrectly use this label on their 28-406.
The 28-406 Durano is probably a good match to your 26x1.3 rear, being around 20x1.1in.

Rob
wrhpv.com

Ignore any tyre size in inches as you can end in big (or small) trouble - there are at least 4 (FOUR) different "20" inch tyres - I have cycles with three of these and so far have managed to keep track of this, but it is easy to get confused - two of the 20 inch tyres are 440 and 451 ETRTO - so close they look the same, but are not - then there are 18 inch 'Birdy' tyres and 16 inch 'Brompton' tyres which are only fractionally different in real life (ETRTO 355 and 349), while 17 inch tyres (ETRTO 369) are bigger than 18 inch tyres.

Just looked at the Dutch Schawlbe 2009 tyre catalogue and there are at least 27 different ETRTO sizes listed - including a fifth 20 inch size.

ETRTO measures the bead seat diameter - the actual diameter of the tyre where it sits on the rim - and this is the size you need to know so you can get new tyres which fit your rims.

The other thing to consider is roilling resistance - the results of various tests by others seem to show that wide slick tyres give lower rolling resistance for small tyres - so unless you are planning to travel at very high speeds (when air resistance becomes the dominant effect) nsrrow tyres are not necessarily the best on the front wheels.

That said, I was using 406 Kojaks on my XXL last summer, and they definitely seemed to be the fastest tyres I have used - and they have the narrowest cross section I have tried at 406 - Schawlbe say 35 but they never looked that big to me.

The Dutch Schawlbe catalogue claims lower rolling resistance for Kojaks than for Duranos, though durability is rated better for Duranos - my experience with Kojaks supports their lower durability rating - I got nearly 1,400 miles out of mine - they were well worn out at the end, though I had only had one puncture.

John Turvey

You got more out of your Kojaks than I did on mine John. 1000 gentle miles and mine were splitting like crazy, possibly due to below freezing weather, and some of those splits caused punctures.

For me Kojaks are a summer tyre and fragile too. I certainly had more punctures in 1000 miles than I've had on any other tyre in 3000.

"I thought of that while riding my bike." --Albert Einstein, on the Theory of Relativity

2007 ICE QNT
2008 Hase Kettwiesel AL27
2011 Catrike Trail.
1951 Engine in need of partial rebuild.

Yes - I looked at my Kojaks when I first got them and decided they were summer tyres - and kept them for summer - I have got two sets of Kojaks for this summer as I am going on a tour which will be longer than 1,400 miles so I will take a spare set with me.

The original query was about fast rolling tyres which is why I talked about Kojaks as they are fast rolling tyres.

John Turvey