[Bike Goes Past Quickly]
- Compared to your previous run
you're basically in the same position,
10 ml up or 10 ml down you're getting better.
Thing is, you can know someone's CDA
but it's how you achieve that is the whole other thing.
[Ominous String Music]
- If you follow the world of professional
triathlon then you will very likely
recognise the name of David McNamee.
In 2015 he posted the fasted run split
in his debut at the Ironman World Championships.
In 2017, he placed third at the Ironman World Championships,
and in 2018 he backed that up again
with another third place finish.
So all very impressive stuff, but it is that
elusive top spot that he is really after obviously,
along with every other pro in the game.
And to add to that we are witnessing
more and more pros turn to this thing
we like to call marginal gains,
meaning Dave has really got his work cut out
for that top spot.
Which brings us to this place here,
because right now Dave is riding around the velodrome
in search for some aerodynamic gains.
So I don't know about you but
I'm very excited to get inside,
see what it's all about,
see how it works,
and see what they're searching for,
and more importantly,
how many savings Dave can make.
[Digital Zings]
Well there he is,
rolling round looking very good.
But obviously he's not out here to make
all these marginal gains on his own.
No,
he has only gone and enlisted the help of
HUUB WATT Bike cyclist and ten-time British champion,
Dan Bigham.
So very excited to sit back now
and see what's about to happen.
- Got David in to effectively try and
find a little bit more aero gains.
Aero is now an arms race,
everything about technology is,
and it's becoming so commonplace for
other athletes to go and aero-test,
whether it's on a wind tunnel,
whether it's on a track,
whether it's open road.
Even now CFD is becoming somewhat commonplace.
So if Dave's not doing it then honestly,
he's falling behind.
So in comparison to a wind tunnel where
you're effectively on a glorified turbo-trainer,
having the wind blown over you,
on the track you're riding your own bike,
we're measuring wind speed,
wheel speed,
power data,
inertial measurements,
effectively tyre loads,
banking angles,
lots of other things and accounting for all that,
all the energy,
figuring out where that goes,
is it to your tyres,
to your drive train,
to you're accelerating your mass,
and then at the end of it,
the equation we figure out your drag coefficient
and we can do that ever single second
throughout your test run,
take an average,
there you go,
make a change,
go back on track,
continue on with the test.
Yeah and then just re-iteratively
just hopefully improve throughout.
We'll do five laps in your natural position,
just as you'd normally ride doing like on the road.
Five laps in your shrink position,
so really focus on getting your head down.
Come back in,
crunch numbers,
change.
Right,
hop on.
[Low Electronic Music]
- [David] Every guy that's trying to win Hawaii
is either in the velodrome or in the wind tunnel,
finding these gains.
I think to win Hawaii it's all about
improving yourself year on year and
I definitely see the sort of efficiency I can improve
especially when I compare myself to all the,
Patrick, Jan and Kienle,
and yeah
it's very much a process every year of
how do I improve?
- [Dan] But is there anything in particular
that screams at you from a,
I feel like this is going wrong or that is going wrong,
I'm sliding on the saddle
or my neck hurts,
my back hurts?
- My neck hurts,
neck hurts.
- Well what we'll do we'll try this run,
I think we'll probably end up coming up,
try it up and up and up until the comfort relieves
see if that means you can hold
the head position for a lot better.
Few things we can try with the helmet again
like we did before with the trip lines,
see if that helps out,
but yeah.
Right we'll run that for the first one.
Grab your lid.
[Tense, Energetic Electronic Music]
- [Presenter] Okay so today you're hearing
a lot about marginal gains now,
marginal gains is the small incremental
changes to our set up and to our position
that actually to a lot of us might seem
rather pointless and rather meaningless
but actually it's this aggregation
of marginal gains that can have
a huge performance benefit,
and that is where this term CDA comes in
and that is our Co-efficient of Drag
it's our aero-dynamic drag.
Now the lower that number the more
aero-dynamic we are and the faster
we can potentially go and that is precisely
what Dave is striving for today.
- [Dan] David's standard position
is coming in at .236 for his CDA,
when he shrugs his head down he gets to 233
so he's saving about 3 watts from his head shrug
which isn't all that much to be honest
most people can get close towards 10 watts
for a head shrug but that's probably a factor of
he does hold a naturally good head position
but also he has a few impingements
at the same time that can't go quite past that
to really get his head super low,
could be a factor of his helmet but
obviously that's a limitation of the sponsorship
so we'll have to run with that.
First step we've gone for is 10 ml lower on the stack height
just to see what happens there,
it's probably the wrong direction I would think
but we've got time to play about so
go with that first and then come back up on the stack,
see where we get to.
[Rapid Electronic Music]
So you were 236,
233,
not sure what's for in your natural position
probably close to that what's in your shrugged
but then it's gonna hurt,
it's gonna hurt so let's come up,
see what happens,
see where we're at,
see if we can reach a nice optimum.
When we've come up,
got to a good point,
then I want to try the trip tape
again on that helmet like we did before,
see what happens there and have a play about
with the extension angle as well.
It's just the tilt underneath isn't it?
[Chilled Electronic Music]
- [Dave] There we go
- [Dan] We're now three runs in,
we've gone lower on his stack by 10 ml
then higher on his stack by 10 ml relative to baseline.
Found about 3 watts both ways,
so where he was originally not all that great
both for different reasons where his head position is
for each of them varies but seems to be a better thing
to be higher in the stack height,
bit more comfort,
his variance as well was a little bit lower
which means he's more stable in that position
his CDA is more consistent which is another factor
we start to look at rather than
just outright aero performances,
how stable is that and how well
you can hold that for the race.
So variance is a way of contextualizing
how stable a position is,
so what we're doing is measuring his
drag co-efficient,
his CDA throughout the whole test run
but also measuring it every single half lap.
How that varies relative to the average
well we express it as a co-efficient of variance
and Dave throughout the test we've been
bringing his stack height up and up and up
and his variance has been dropping as well
so it's just another good measure of how
stable and consistent he is at holding the position
and shock-horror being higher,
more comfortable means he can hold his
position more stably.
- [Presenter] So it's finding that balance point, right?
- Yeah exactly that,
so we have gone too high,
we've gone over that tipping point,
and aero-dynamically took about a
5 watt hit when we went too high
so we've come back down,
still in a very stable position,
but also aero-dynamically optimal,
and then started to move around with his
arm angle now to see what we can do with that.
Cool, just going to measure the extension tips so
Right okay we're bang on 102 so we'll go to 105.
- Okay so we're full flow here,
they've played around a lot with the elbow height,
the arm height,
and also even the hand height so
they've figured that bit out,
now onto the saddle height so
they've actually dropped it down by 10 ml,
we're going to see what the results are from there.
- Right this is okay when I'm like fat
during the winter but as soon as I get skinny
- [Dan] You've got no padding so what we'll do
we'll come up 20ml from where we are now
so back higher.
Everyone is different.
Every person has different flexibilities,
has different limb lengths,
different ranges of movement,
and it just means your bike position
is of course going to be different
so you can't just take what works for one person
and apply it to another so you've gotta
go through that testing loop and just
optimize and it's not just a straight-up science,
there is some trial and error to it,
you need to try different things
and see what works for each person.
[Bright Electronic Music]
- Okay Dan that looked really exciting down there,
what's the results of today?
- So really productive day all round,
with David he's come for the last two years on the trot
so fairly well dialed in,
knows what works for him,
but each year equipment changes so
you're just re-optimizing around that.
So first thing we did,
we went through a stack-height sweep
in the end we got him 30 ml higher than baseline
and I think he's about 5 watts better off
across his two head positions,
so his natural head position and his shrugged.
- So that's quite interesting,
so we've gone higher when a lot of people
obviously think that slamming it is faster
so what's gone on there?
- To be fair it tends to be new skin-suit technology
means you can tolerate a higher back-angle
but the other advantage is by being higher up
you're more comfortable and you're head
can come down a little bit lower
and your head being obviously not a very
aerodynamic shape if you can get it low,
get it hidden away you can really
reap some good benefits from.
- Great so what's the overall saving?
- So overall saving just in position today
I think off the top of my head it was
about 8 watts in his natural position
and 2 watts in his shrug
which just shows his shrug's more,
okay it's not a big gain but it means
if he can hold that for longer
then he could be in a better place.
- So why do you test the two different positions?
- Primarily because if you were to make a change,
for example an armrest change,
you come narrower,
then your ability to shrug and pull your head down
it can be severely reduced and we want to
effectively assess the impact of
what you would do naturally but also
what you would do in a shrug position,
because we know you can't sustain them both, sorry,
you can't sustain a shrug position
for four-five hours on a bike,
I'd be amazed if anybody can so you need
to assess the impact on both sides of it.
- Okay so 8 watts sounds quite substantial,
so what does that,
I mean what does that equate to?
- So good rule of thumb for pretty much anybody out there,
most guys between 40-45k an hour,
would be 10 watts would save you a second
every kilometer that you're riding,
so Dave's case,
8 watts,
about 2 and a half minutes for an Ironman.
- That's pretty big isn't it?
- Yeah he's fairly happy with that,
he comes away and he's in a better place
he's confident with what he's doing,
he doesn't have to tweak about with his position
he can just settle in,
get stuck in and just go.
- Yeah so not only can he maybe even bike faster
but also ride at the same pace,
save energy for the run.
- Exactly that,
in Ironman it's not so much an out-and-out time trial now
you're racing against people rather than
racing against the clock so he goes to
Tacona and for him it's actually just about
getting to that run in a good physical state
to basically go and run all the uber-bikers down
and then hopefully get onto the top step of the podium.
- Well that has been an absolute fascinating day
and a real insight into the level of detail
that pros are going into in that search for
those marginal gains that we so often hear about.
Now Dave has saved himself an incredible 8 watts today,
which is really quite substantial
and a substantial amount of time over an Ironman distance
I mean that could have been the difference
between his third place finish
and that second place finish and maybe even
that elusive top spot come 2019.
Now obviously the real test now is
whether he can transfer that to the race itself
we do wish him the best of luck with that
and a real big thanks to Dave and Dan Biggum
for inviting us along today cause it has been
a fantastic day so if you liked today's video
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