- If we look like we've just done Parriere Bay,
we kind of have.
This morning we set out from the Arenberg Forest
to look at the final 100k's of this year's race,
a video which you will hopefully see soon,
if it's not out already.
But now we've arrived here at Carefore De Labe,
we decided this would be the perfect place
to do our follow up experiment
to the tyre width test over cobbles,
which was a little bit inconclusive.
So we're gonna use this sector,
for a tyre pressure test.
And what a sector it is, it's one of the roughest.
It is the third and final of the five star sectors,
in Parriere Bay, I think there are
only four more sectors after this,
only 15k through Rebay Velladrome.
We're not gonna use all of it,
let's face it, we're a little bit tired now,
so we're gonna use one point, one kilometre.
Starting down there, and heading
in the direction of the race.
And finishing just here on the famous left hand corner.
- The experiment is very simple,
Matt and I both running Continental
Grand Prix 4000 tyres, in the size 28 millimetres,
and we're going to do three runs.
Slightly regretting what I wrote down to do,
because we're gonna do 100 PSI,
and then we're going to do 70,
and then we're gonna finish with 45 PSI.
Now I think we know which is going to be the best,
which is going to be the most comfortable
and probably the fastest as well.
But what we want to try and find out,
is just how much different it feels.
- I certainly know that 100 PSI
is going to feel very very different
than 70 and 45, I can't believe
you're making us ride 100 PSI,
but we've got something else I believe.
We've got a brand new bit of revolutionary
technology to measure the vibrations
of the Carefore De Labe.
- We have. - Take it away Dan.
- As well as subjective feeling after each run,
we're also using a very high tech,
just out, vibration sensor.
- Show us it then Dan.
What's it look like?
- There we go, it's a GCN couerback water bottle,
which I will fill to the top before each run,
I will then remove the top like that,
and then we'll see how much is left
at the end of 1.1ks.
- That is some seriously low fi tech.
(upbeat music)
- Run number one then, 100 PSI.
And quite frankly, I'm frightened.
I designed this little experiment,
and I'm regretting it now, having ridden
down that section of the Carefore De Labe.
It's so brutal, and,
(taps on tyre)
don't know if you can hear that,
it's pinging, not gonna be very forgiving at all.
I'm glad we're getting the worst one
out of the way to start with.
Okay.
Three, two, one, go.
Right moment of truth,
oh too bad.
(groans)
Actually really bad.
Oh my goodness,
it's got quite a crack already.
Ah.
= Three, two, one, here we go, get my feet in.
Blimey that's bumpy.
Well I lost my bottle straight away!
(laughs)
Well, two minutes and 23 seconds,
really really quite horrible.
I was all over the place.
Especially this last sector,
where it's really really broken up
and the cobbles are all sorts of jagged angles.
It's actually a little bit sketchy,
but really found it hard to apply the power.
'Cause the bike was just skipping all over the place, so
definitely not the PSI I would choose, 100.
- That was horrific.
I've got pins and needles.
Two minutes 39.
Oh yeah.
Not much left in that.
(upbeat music)
Run two then, slightly more forgiving 70 PSI.
(electronic music)
Still quite bumpy.
But a bit better.
- Run number two, 70 PSI.
So run number two, 70 PSI,
far more comfortable, still pretty jarring.
I still wanna drop the pressure.
Again, found it really really hard to lay the power down.
Easier on the smoother section,
but on the bumpy section,
I felt very difficult to get the power down.
But anyway, time of two 11,
so that's 12 seconds quicker than my previous run.
- 20 seconds quicker,
that felt a lot better already.
Taken 30 PSI out, not much difference
on the high tech vibration sensor here.
Probably got about an inch.
Final run then, and I've decided
to risk going down to 45 PSI on this one,
which is three bar.
Now hopefully I won't pinch pump,
so that is the risk, especially
when you're running clinches like we are today.
Bottle is filled up,
three, two, one, go.
(upbeat music)
Oh now that, that is better.
- Final run for me, 45 PSI.
I'm hoping this is a bit more comfortable.
Three, two, one.
(upbeat music)
Okay, two 01, so took another 10 seconds off.
So so much more comfortable,
and I could actually
lay a bit of power down as well.
Whereas before, especially run number one,
it was, I wouldn't say impossible to put power down,
of course, but, bike went everywhere,
but this time, yeah I was kind of
gliding a little bit more.
Still brutally bumpy,
but it felt like I was making some headway.
So, yeah best by far.
- I didn't press it towards the end,
quite as well, so that would have
been about two 14 I think,
but I didn't press the button properly.
Not much difference though
on the high tech vibration sensor.
Same for the three runs.
Well where better to do the conclusion
of our tyre pressure test than at the
Rubay Velladrome itself.
It has been quite interesting,
because I wasn't expecting it to be
quite that bad with 100 PSI.
It was so brutal, wasn't it?
If I ever say again, "Let's go do an experiment
with 100 PSI on the tyres,
over a cobble section like that", just shoot me.
- I think I'll just book annual leave,
I certainly wouldn't ride a
100 PSI through there again.
But Dan you were riding completely on fuel weren't you?
- Yep.
- So what was the time differences
between runs one two three then?
- It was about 20 seconds, just a little over.
So the worst obviously when we had 100 PSI in.
But you can just pedal more can't you?
When you've got softer tyres, and less pressure,
you can pedal further across the cobbles,
and therefore put more power down.
Pretty simple.
- Well for me, I was right.
I was gonna and ride to around 250,
sort of 280 watts, which is pretty modest.
Started off quite quick on the kind of
first section of cobbles, with 100 PSI,
and from that point onwards,
I just couldn't get the power down.
Same sort of perceived effort for every ride,
but for ride number one with 100 PSI,
it was a quite modest average watt.
Then when we took it down to 70,
a lot better, I improved by 12 seconds,
got a bit more power out.
Then on the final run, with 45 PSI,
I was the quickest by 20 seconds,
and managed to put another 15, 20 watts down as well.
So yeah, the more I decreased the pressure,
the more I was able to apply power,
for the same perceived effort.
- [Dan] Yeah.
Well the vibration sensor didn't really give us much
in the way of a conclusive statistic, did it?
- [Matt] No, I don't know if that
will really catch on, to be honest with you Dan.
- [Dan] But we can safely say that softer tyres,
are much more comfortable and faster
over Parriere Bay.
And you wonder then, where Parriere Bay tech
is going to go over the next few years.
Because there are bikes out there now
that are optimised to be aero, with the bigger tyres.
So perhaps, could we get to a point
where we see a rise on 35C tyres,
if they're not an aerodynamic disadvantage?
- Or will we see the powers that be,
the UCI, step in.
- Yeah.
- And put, because you know,
it's interesting but, will we see
rides in the next few years
riding all terrain grow bikes?
- Could do, if they're aero enough.
I mean, you were quickest last year
on a mountain bike, out of three different bikes.
- With my arms like this.
- Yeah.
Well all interesting stuff.
I hope you've enjoyed it, more than I have today.
Right if you'd like to see that experiment
that they did just 12 months ago on three different bikes,
mountain bikes, cycle cross and road bikes,
you can find that just down here.
- Don't forget to give this video a thumbs up.