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47c vs 35c tyres for speed/efficiency when touring

by badgerjockey
Thu, Jul 02, 2020 11:44
2

I've been reading up about the move towards wider road tyres to reduce rolling resistance, increase comfort and, potentially, speed. It seems that for racers, there is a sweet spot around the 28/30mm mark beyond which the benefits of the counterintuitively smaller contact patch of a wider tyre begins to be outweighed by the loss of aerodynamics...

There's loads of info about this for this size bracket of tyre, but less so for wider, touring tyres.

I have a hybrid framed tourer and have had 47c 1.75in Conti Contact tyres on it for years. Really comfy and have served me well touring in places like Morocco and Jordan where the tarmac can be poor in out of the way places.

I'm just about to do the Lon Las Cymru, Wales end-to-end and have on a whim bought some 35c Schwalbe Marathon Classics on the off chance that they might roll faster than the 47cs on the good tarmac expected on this route. They are also about 250g lighter each than the Contis.

Am I right, though? According to Bicycle Rolling Resistance the marathons have much less rolling resistance and less weight, but what about internal friction, contact patch sizes, etc etc? The marathons have noticeably stiffer casing and obviously higher pressures...

Sorry, probably just getting myself all confused for not much difference and should've saved the £55!

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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2 comments

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Joe Totale | 3 years ago
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The 35's should be fine for anything this country can throw at you and should be significantly faster than the 47's.

With regards to fast tyres, as stated below 25mm tyres are still the fastest, modern wide rims usually stretch then out the 27-28mm anyway and if you run them tubeless there's more than enough comfort.

Anything wider will disrupt aerodynamics, that's unless you've got some of these new, fancy extra wide wheels which are made for 28's.

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EddyBerckx | 3 years ago
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It will be noticeable in my opinion. 47mm tyres are great at easy cruising speeds but 35mm will be easier no doubt. Fit them and see!!

And racers haven't settled on 28/30mm tyres in all honesty, 25mm is king...but as with so many things bike related, if you are simply cruising and so on anything that is meant to make you go faster on a bike (lower weight/more aero and so on) is far less noticable the slower you go or less effort you put in.

You may find the 47mm tyres give you a more enjoyable ride. In which case put them back on

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