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Do Deep Section Wheels Climb Faster? | GCN Does Science

October 9, 2019


– These are the brand
new wheels from Shimano. They’re gonna become available
a little bit later this year. And we’re gonna use them
for a little experiment. Now, this one here is the
C40, and this one is the C60, and both are completely new
to Shimano’s wheel lineup. This one, the C40 has been
designed as an all-around wheel. Super-light, just 1,355g
but yet, also aerodynamic. Shimano tell us in fact
that it is two watts faster than their previous
aerodynamic wheel, the C50. And they’ve achieved that partly through a new rim
profile, and partly, they say, because they’ve made it much, much wider, so it sits much better
with modern wider tyres, so it’s actually 28 millimetres
wide, so wide in fact, that they’ve produced their
own slimline brake pads for it. This one, the C60, however, is the out-and-out aerodynamic wheel. If this one creates two watts
less drag compared to the C50, this one creates 16 watts less drag, so that is significantly faster, although Shimano haven’t
actually told us exactly how they have tested those
wheels, but what I want to know, and what I’ve always wanted to
know, is just to see how much difference there is between
shallow wheels and deeper wheels when climbing. We’re told that this is a climbing wheel. But yet this one is just 125g more, and creates 14 watts less
drag at higher speeds. So, we’re gonna find
out exactly what happens when we put the two head-to-head. Our climb of choice today
is the Coll de Rates, which is in Alicante in Spain. It’s 6.5 kilometres long,
and 5.6% average gradient, so it should be reasonably quick. Any guesses? Run number one, it’s the C40s. (exhilarating music) (exhaling) You ready? Run number two, C60s. All right. (stimulating music) (exhaling) With two runs of the Coll
de Rate under my belt now, it is time for some results. I’ve not seen these yet,
so I’m just gonna click into the lap function. Right, here we go. So the C40s were 16 minutes, 52 seconds, and the C60s, 16 minutes and 55 seconds, so actually, two and a
half seconds between them. I can’t quite believe that. That’s unbelievable. An average power for each one was 326 watts. Now that’s not guaranteeing
that those watts were laid down in a completely even manner, so there could be a bit
of discrepancy in there, but that is uncanny that
they’re almost exactly the same speed at that climb. I suppose you could extrapolate that and say that if the climb is
any steeper than this one, which is 5.5%, then the C40s
are gonna get progressively faster and faster compared to these, but you can bet your bottom dollar that these C60s are now gonna
be a heck of a lot faster down the other side. Which one matters to you,
I suppose ultimately, is a decision for you. But, I can’t believe that. That’s almost slightly weird, isn’t it? Right, well. If you have enjoyed this
little dip into science, then make first of all
that you subscribe to GCN. We regularly try and tackle
some of your burning questions about cycling and cycling
equipment with the help of helpful brands like
Shimano that lend us this amazing stuff. And then, once you subscribe,
back here on the globe, why not check out a couple
other GCN Does Science videos, where firstly, we test
out how much of an effect bike weight has on climbing speed. That’s just up there. Or, Matt and Dan put on
fat rucksacks to find out how much body weight
affects climbing speed, and that one is just down there.

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