How Much Does Weight Affect Your E Bike Riding? | EMBN Investigates

How Much Does Weight Affect Your E Bike Riding? | EMBN Investigates


– The goal of any
competitive cyclist is to be as light and as strong as possible, both in body, and in bike. Now, it’s simple physics. The more or less you weigh,
the more or less energy is gonna be used to
pedal your bike uphill. But this is an e-bike ride, who cares? The battery and the motor have
got your back at all times. more energy, free energy. So, who cares about such things
as power-to-weight ratios? (energetic music) Well, we often talk about
the power-to-weight ratio, especially on road bikes,
and on cross country bikes. But what actually happens when you lose a big chunk of your body weight? What’s going to be the
effect on the battery, and your speed up that hill? Well, today we’ve got a real hill, and we’ve got a variety of weights, to see what the difference is
between the climbing speeds, and the drain on the battery. So, how are we gonna do it? Well, I’ve got this specialized Kenevo, which is 180mm travel. I’m gonna be riding in trail mode. The hill behind us is
gonna be about 1,000 feet, which is 305 meters, spread out over 5k, which gives us a gradient of about 7%. The trail itself is gonna
be a mixture of fire roads, and technical single track. Gonna do two climbs. The first climb is gonna just be me, and my body weight, and
my water bottle full. And then the second
climb is gonna be again, myself and the water
bottle, and a 15K backpack, which is gonna be pretty tough. So, why 1,000 foot you ask? Well, it’s about the height
of a World Cup downhill track in terms of vertical descent. So, I’m really interested
to see how much battery the bike uses and how quick it is to get to the top of 1,000-foot, 305-meter hill. (inspiring music) Right, so run one, 1,000 foot
is not an insignificant climb, but during the run I’m
going to be trying to output about 180 to 200 watts through the cranks. My heart rate’s gonna be about 132. So, there’s a bit of …
There’s a quite moderate pace. I’m gonna be going up this hill to kind of sustain that speed. I’m gonna be using the
Specialized Mission Control App, which is gonna give me
outputs on battery usage, how much power I’m putting
through the cranks, and the run time, and the elevation. (exciting music) There you go. Run one, steady pace. 18 minutes and one second. Now, at that climb, I tried
to keep a steady pace, and because it was of
that gradient, you never went beyond the 25
kilometers an hour barrier. So, yeah, 18 minutes, and we’ve used 16% of the battery, so,
it’s about 75 watt hours. Now, the battery on this
bike is 504 watt hours. That means, on a 1,000-foot
hill, I could actually get about six to seven runs done. Which is pretty good for one battery life. But, do you know what? I’m not gonna be doing seven runs today. So here we go, run two. Got the backpack on me, 15 kilos. Now, the boss told me to
go easy with the weights, but this is like having a World Cup downhill bike on my back. (mystical music) Could’ve left a halfway
point with a 15K backpack. I’ll tell you what, it’s quite
a grind, quite different. But, so far, I’ve just about
managed to keep the heart rate, and the watts through
the cranks about the same as my first run without a backpack. I’ll tell you what, though,
you don’t want to try this. It’s ridiculous. To put it in perspective,
my colleagues at GCN, they did a similar test on power to weight a couple years ago,
and they did a 5K climb over a seven degree gradient,
in about 22, 23 minutes. But they were a lot fitter than I am. But if you’re interested
in seeing the time, this backpack on, I can tell you. (mysterious music) Whoa, wow! Oh my God! 20 minutes and seven seconds, that’s over two minutes
slower with a 15K backpack. It was actually quite
different to ride that as well. I was constantly changing
gears to maintain the momentum and the cadence,
so that my heart rate, and remember, the power
through the cranks, was equal to my first run. But, yeah, wow, that’s quite
different to the first run. But what does all this mean? Let’s go to the pub, and find out. So, I’ve been analyzing all the figures over lunch, and I was wondering. You might be thinking:
Why on Earth did I chose a 15 kilo backpack to pedal up that hill? Well, there’s a reason behind
it, and that’s because, me, on a good day, fighting
fit, weighs about 90 kilos. And, to put it in a
mountain bike perspective, Enduro World Series champion, Sam Hill, weighs about 75 kilos,
and World Cup Downhill champion, Aaron Gwin, 75 kilos. So, I really wanted to get
insight to how it felt, going up that hill at different weights. So, as we mentioned
earlier, the more or less that you weigh, the more
or less energy it takes, to pedal your bike uphill. So, what do the figures tell us? Let’s go into the detail one by one. Okay, first up, let’s
have a look at the actual time difference between each run. First up, the run without a backpack was 18 minutes and one second. Now, compare that with a 15 kilo backpack. Two minutes slower. 20 minutes and seven seconds. Now, that’s a huge,
huge margin for one run. You try standing on the side
of a fire road for two minutes. It’s a lifetime. But, I think the important
thing here is that, imagine doing six or seven runs and the time difference it
would be when you do that. Okay, let’s move on
and see how much actual battery was used during each run. The first run, without a
backpack, the bike used 16% of it’s battery life,
so obviously quite a lot. But the second run, with a 15K
backpack, 19% of the battery. Now, that’s actually closer
than I really thought it would be, considering the amount of weight that we’ve put into the system. So, that kinda gets me
thinking: Well, if the 15 kilo backpack only uses 3%
more battery, then … Kind of implies that a five
kilo difference is only gonna make a one percentage
difference in the battery life. These are rough figures,
I know, but, from that, it’s made me think that: Well,
if my bike was five kilos lighter, then it’s only
gonna make 1% difference? That’s not very much. And then, it also makes me think that: If I was to lose 5% or five
kilos of my body weight, then, that’s not gonna make
a huge difference either. So, maybe we should be looking
at watt hours used as an indicator of battery life instead. So, let’s have a look at these numbers. Now, without a backpack, 75 watt hours. That’s quite a good chunk
of battery life, yeah? With the backpack, 89 to 90 watt hours. Now, Specialized Mission
Control App is really good at giving you all this
data, to analyze this. And, it’s got me thinking:
Well, that’s quite a big difference, actually. You’re looking at the difference between, if you’ve got a 504 watt hour battery, you’re gonna be able to
get six to seven runs without a backpack, 15 kilo backpack. Yet, if I put my backpack on, that’s gonna knock it down to about five to six runs. So, you’re gonna get a whole 1,000-foot difference between that weight. So, it is actually quite significant. So, I did the two tests, and then I sat around thinking: Well, I’ve still got a ton of battery left. So, What would it be like if I
stuck the bike in turbo mode, and actually buried myself,
gave it maximum beans on the climb, and that’s what I did. So, my time was actually 13 minutes. That’s a whole four
minutes quicker, in turbo, than it was with me in trail mode and, what was quite interesting,
was that I actually only used 100 watts of battery during that run. So, I could actually get
five runs down on turbo over a 1,000-foot hill,
which is actually a load more than I thought I could. Obviously that was on a
smooth kind of gradient. So, There’s loads to think
about here, and we’re really gonna be exploring this
over the next few months, and when it comes to e-bikes
and battery life and weights. So, there you go. If you want to see more
about analyzing e-bike runs, there’s a good run on
downhill versus e-bike, which is down here. If you want to see more
technical things on motors, there’s this video here to check out. If you like this video,
and would like to see more, please give us a thumbs
up, and I think that the subscribe is around about here somewhere, right Tom?