Light Bike Vs. Heavy Bike – What’s The Difference On A Climb? GCN Does Science

– [Matt] GCN does science. – [Simon] #data. – A while ago, we tested the effects of a
bike weight on climbing speeds, but in a laboratory setting. And while this is
undeniably the most accurate way to test it, there’s a big part of us
that still wants to see what the effect is out on the open road. – And what better place to do than here
on the Colle del Sestriere? The scene of many battles in the Tour de France
and the 2015 Giro d’Italia. – Yeah. So what we’re going to do,
Matt and I are going to do two runs of this climb, each. Now, it’s about eight
kilometers long, an average gradient of about 7%. I am going to use my Garmin
bike to power me to ride at consistent power both runs, and then I’m going to do
the second run with two kilograms of ballast added to my bike and then
we can compare the times directly. – I’m going to do exactly the same but my
power meter is going to be in here, old school, all on feel because I think
that perception is still really valuable and very, very important. – Yeah, you calibrated this morning? – It took me a bit of time
because obviously we’re at altitude, but it’s pretty much spot
on and I’m ready to go. – Let’s do some pedaling. ♪ [music] ♪ – My bike weighs in at 6.920 kilograms
without weight, and then with a full water bottle, 7.595. Then finally, with ballast
added, it comes in at 9.505. So that’s a differential of around two
kilograms taken into account the full water bottle on both runs. So round one,
the ballast bike, let’s give it a nudge. ♪ [music] ♪ – Just trying to keep a nice rhythm, keep
my breathing controlled which is actually harder than you think at altitude. But I
think I found a good level which I can sustain for the half an hour
effort, there abouts. ♪ [music] ♪ – Okay then, first run, light bike.
Let’s give it a go. ♪ [music] ♪ For my support,
kind of feels like normal. ♪ [music] ♪ Well, round one done.
That was pretty tough. – This is quite a hard climb, isn’t it? Especially with the altitude,
but well, let’s do it again. – Indeed. Well, we’ve been doing
the comparisons until round two, but I think might need a quick lay down. – My bike weighs in at 7.3 kilos
and that’s with a Garmin Virb on the handlebars, obviously.
With a bottle, it takes it up to 7.875, then with the ballast, it weighs
in at a pretty hefty 9.8 kilograms. ♪ [music] ♪ It feels weird getting out the saddle.
You can feel the weight of the bike. Definitely nose room ahead. ♪ [music] ♪ – So, ascent number two coming up,
just hope the legs hold out. See you later. ♪ [music] ♪ I’m trying to keep the same effort,
perceived effort, so it’s difficult and breathing’s controlled, but the bike
does feel just that little bit lighter and more spritely on the steep sections. And I think I’m going a little bit
quicker, only time will tell. ♪ [music] ♪ Sorry, I can’t speak. – All right. Now the results are in,
but before we give you them, we must stress this is not a controlled
test. So this is purely for discussion only. We can’t account for things
like wind or anything like that, but it is nevertheless very interesting.
On my bike, so I was riding to an average power of 320 watts on both runs. I was 35
seconds slower with the heavier bike. So it doesn’t actually sound like all that
much. It’s only about 2% of my overall time. But Matt on the other hand,
Matt was really interesting. – It was. Well, I went on the light bike.
I went one minute and three quarters quicker. Now that was for exactly the same
perceived effort so in relation to that, it was the pain in my legs and also
my breathing, and that remained the same for the whole of the each ride. And where
I noticed the difference was when the road pitched up above 7%, 8% gradient and the
bike felt far more responsive and I could use a bigger gear on the steeper parts.
I think that’s where I made up the time. – Well, and even more interesting was that
it was your second run when you were on the lighter bike so one would have
thought that you had a bit of fatigue in your legs there. So, conclusions then.
Well, perhaps if we’re after pure performance, clearly we can see that a
lighter bike is going to be faster on a climb but the difference isn’t necessarily
as big as you’d think. But when it’s out of pure enjoyment and perceived
effort, it made a huge difference. – It certainly did. – So, maybe there it is. A lighter bike
will make you go faster but it will feel even faster than that. So that’s our
experience, but we’d be really interested to know what you guys think.
Have, for example, you recently got yourself a lighter bike
and did you notice a difference? Let us know in the comment
section down below. – Yeah, and for other GCN
Does Science videos, click up here. What makes the bigger difference,
a lighter bike or a lighter body? – We know really though that your legs
make probably the biggest difference of all, so don’t abate your training. Check out the GCN training
playlist just down there. – And remember to subscribe to GCN, it’s
absolutely free. How about clicking on our rather fatigued legs? All that
love, rather beautiful mountain, too. I’m absolutely fodder, are you? – Yeah, pizza? – Definitely, and a cappuccino. Here we go, round two. Let’s just hope
the legs hold up. See you. Awesome. Here, that actually just keeps
my hair in place. Can we do a dry run? – Did you get that? – [Cameraman] Yeah.

100 thoughts on “Light Bike Vs. Heavy Bike – What’s The Difference On A Climb? GCN Does Science

  1. Of course the lighter the bike the faster it goes specially in uphill. But what about downhill or in a straight highway where it is moving very fast. I think heavy bike will give more stability rather than the light one specially at high speed. Since at a very high speed lighter bike will tends to be unstable.

  2. I used to commute on a road bike, after it went to the shop I started using a mountain bike which was about 4 kg heavier. Within the space of months.

  3. since GCN likes to cooky videos, lets see a heavy bike vs light bike downhill. 😀 bet I know who'd win.

  4. They would shit themselves if they rode my old mtb with paniers, three waters and the Deliveroo crate attached. Weighs a ton but I ride 60km a day haha

  5. If one's goal is general fitness rather than competing then a heavy bike is going to put on the muscles more than a weight-weenie's wobbly job.

  6. I'd like to hear the gents comments on the Rohloff 14sp hub gear. My comment: Bit heavier than the filthy derailleur contraptions but the joy of 14 ratios covering 520% (or 5.2:1) – at EQUAL INTERVALS – all in a straight line – instant selection whether moving or stationary makes me never want to go back to the Der derailleur. Acceleration: half a pedal turn and click – 3 or 4 times and I whistle past most der-herberts on take-off no worries. No time lost as the primitive der-man's chain graunches 'orribly cog-climbing over the cassette while he eases off the pressure losing time. I am a convert.

  7. Between my Specialized crosstrail and Scott speeder I've been doing most of my riding lately on my
    Specialized, it is very heavy compared to my Scott but it is more durable for rides that I'm not familiar with plus it has a rack on it. So I can get stuff done more so then on the road bike; the best is when I go from the heavy one back to the road bike I fly down the roads. So time allowing, I get a heavy work out on the Specialized. But bike what you want to race is what I'm told.

  8. I got 13 KG of body fat I need to shed. I can only imagine biking once I get ride of all that extra body fat. That would be riding a 13 KG bike and having it go to 0.

  9. A comfortable bike makes a far greater difference for overall riding enjoyment. I prefer more durable components, which typically come at a weight penalty, but are easier on the pocket book. A few pounds doesn't matter in the grand scheme. All that mass eventually goes downhill faster, so you can pick up a few lost seconds. Also, a heavier bike will handle the cross winds better, and it tends to dampen the gusty head winds. Think of a flywheel in a car, a light flywheel spins up faster but since it has little mass, once the power is removed, it slows down fast. A heavy flywheel takes longer to spin up, but once at RMP it has the inertia to keep it spinning. When a gust of wind hits a heavy bike it won't slow it down as much. You're right though, in a pure climbing race, the lighter bike is an advantage over a heavier bike. However, in a long endurance race, a light bike has less meaning, especially when a component breaks. Cool video though. It's nice to know Newton is still right after all these years.

  10. One big Word, Cardio Conditioning for Dummies. If your a pro then everything on your bike matters, For all you Punters out there blaming the bike for your short comings. Fuck off

  11. It "feels" faster to ride a lighter bike because of the lighter wheels. Rotational mass has a far bigger effect on how you perceive the bike in relation to static mass like your frame. Though this mostly just affects acceleration and climbing not so much sustained speed, that's why a really light bike almost feels like it wants to leap when you really push the pedals. Basically change your wheels for a pair of really light ones and the bike will feel much faster and more fun, though you won't really gain a substantional gain in terms of how much time you saved, that's really down to how strong of a rider you are and also your positioning and effectivness when pedaling combined with stamina. I guess long bike races that last for hours are a exception where time could mean a bigger margin in the long run.

  12. My 12 year old MTB weighs in at 16,2kg , I might need to invest in a lighter bike when I've lost some bodyweight

  13. We don't just go up hills, we go down them as well. What about on the descent? You would expect the heavier biker to gain more speed. Would it even out? Like to see you do the test up and down and compare the results.

  14. Recently got a full carbon Kestrel and I can tell l am a lot faster on the same routes I had ridden many times in the past on on my Aluminum bike with Carbon fork. .

  15. After years of being a mountain bike fan,especially after the front and rear suspension systems came about, I finally said to myself I'll get a road bike just to see the difference and wow,my trip times were almost cut in half.The smaller wheel width that applies less contact/friction on the road, plus an aluminum frame,is just great.I am kind of annoyed at myself why I didn't try it sooner.I believe mountain bikes with front/rear suspensions actually absorb a lot of the kinetic energy a person applies in trying to accelerate,this is wasted energy that could be making you go faster.Forget the hype of suspensions,go for a good road bike and watch your travel times plummet.

  16. Should have been a blind experiment, in my opinion. The flaw behind their method was that they knew how heavy the bike is before their ride, which would introduce biases in their results that lead to inaccurate conclusions. Also, they could use a placebo (i.e. a ballast that has negligible weight but the riders perceive an added weight) to examine the riders expectations of added weight, which would be quantified in their performance. Also, more riders as subjects in addition to more rides from each individual for repeated measurements. Interesting results nonetheless! 😀 I reckon I could be a consultant for the GCN experiments… Put my bachelor's degree to good use 🙂

  17. I have managed to make my bike "lighter" by changing the wheelset. Without my saddle bag of tools it now weighs 12Kg. It's a generic 4130 steel frameset. I love steel and seriously looking at the Bombtrack Audax which is close to 10Kg. Will I notice a big difference in hill climbs?

  18. You're missing a major point here. Not all things are equal between light and heavy riders. How much of a percentage does the bike weigh in comparison to the rider is very important. E.g. For 55kg rider a 10kg bike makes up for a massive percentage of his/her total weight, where as a 80kg rider it makes for a very small percentage of the total weight. The lighter you are the lighter the bike you needs to be to maintain the same advantage/gain as the heavier rider.

  19. I got 9kg road bike and overtook guy on superlight new bike sitting while he was standing, if I had bike like he did he couldn't even see me I'd pass him so fast but I don't want his bike cause it's a plastic junk it was making clicking noise on every turn of the crank…

  20. I alternate between a road bike and an ancient rigid mtb – the weight difference is only about 10lb, but the difference going up the local knackering hills is HUGE. You can make them just as knackering on the lighter bike by going faster, obviously, yet it somehow doesn't feel like such hard work – just psychological I suppose – the 'perceived' difference?

  21. I am riding a 14,5 kg (32 pounds) bike, have a weight of 108 kg (240 pounds), two bottles of water 1,6 kg (3,76 pounds) on longer rides and a backpack (bananas, pump, inner tube, some curd snacks, extra shirt, even more water) of 3 kg (around 7 pounds). So any hill is a complete nightmare! But I love cycling 🙂

  22. I ve been riding a Specialized Secteur sport triple (2014) with aftermarket upgraded wheels, which weighs more than 11.5kg with saddle bag but without any fluids. I have given up some climbs…

  23. Also, rather than simply adding ballast to a bike with awesome wheels, wouldn't the weight of a cheaper heavier bike be partly in cheaper, heavier wheels?
    I'd be interested to see what sort of difference the whole package difference makes, eg heavy bike has 105 and cheaper wheels, lighter bike has Ultegra and upgraded wheelset.

  24. When the watts were the same the difference came out to 2-3% which is what we would expect given the weight difference
    "+/- 2 Kg / 80 Kg" However I think the perceived exertion test was valid in the real world and the differences do magnify – which is why the TDF riders look like they are starving. From my own limited experience a better and lighter bike magnifies the difference on the steep sections more than the different weight would make you believe. The better bike encourages you to apply more power. Maybe it's because the faster you go, the less time you have to hold the higher wattage.

  25. hahaha your fully loaded heavy bike is lighter than my steel frame Jamis! No wonder I fly downhill and downhill only!

  26. why dont people train on a really heavy bike. then it would make you stronger and faster for a lightweight bike race. light bikes just make you weak

  27. I kind of wish they would have attempted with more weight, but I guess the results still proved a point. Also would have been interesting to see some peak and average heart rate results, they kept the wattage the same for each ride, but that doesn't mean the effort was the same.

  28. I had a Trek 1997 7300 multitrack hybrid. Riding with a group of friends,they all left me behind. My breathing was heavy going up slight hills and struggled up steep hills. Ready to pass out. I since then went to a bike shop and purchased a 2014 Fuji Gran Fondo (carbon frame). Night and day to riding my old trek. All hills were a breeze my breath control was a lot better. Beat my destination time by 5mins. So happy I upgraded. Now all I want to do is beat my current time on the course. Big difference in the two bikes.

  29. And here I am with a 60 pound bike (Nearly 30 kg). I've got a 750 watt motor on it though, which more than offsets the extra weight. It's great for commuting.

  30. Ahh, I hope I find out what it feels like to ride a high end climbing bike. Mine's 12KG without the two bottles, spare tires and my bag. While I did learn to gently fly past parts where in the beginning I was destroying my knees in the lowest gear with a dangerously high heart rate, I still want to go further and faster. I think that by the time I have enough to buy that Pantani Edition Specialissima, I'll be well into my 50s.

  31. Lmfao I have had so many arguments against morons who think double the weight makes no difference lol. Weight is 80% of the difference the rest is leg strength and bike aerodynamics. There is a reason why the Tour De France bikes are not all 29 lbs. The lineup of people at that weight of bike , well most pros would not even participate. I go up hill on a 29 lbs alloy with 25 km/ hr wind coming at me and still maintain 20 km/hr speed sitting down . Climbing is very difference than flat areas.

  32. i cycle for fitness and prefer a heavier bike as i have to work harder. I have a light road bike but i never feel like i have done a good workout on it over the same sort of distance.

  33. My 31 mile commute is all climb, and I generally bring along my lunch, change of clothes, and laptop in my rucksack. One of these days I'll try the same route without my rucksack, it'll feel wonderful I'm sure.

  34. Hay GCN my name is Avi_ban and i from Israel and I want to become part of the community of GCN and help you to grow from here also how I can to send you videos

  35. Can you guys do a test on a complete course of uphills, downhills and flats in one ride? Would be interesting to see what the difference is then as the heavier bike would be better downhill and on the flats not that much different perhaps, especially if you end at the same point so total ups and downs would be equal.Also do the test "blind"  so you dont know which bike is the heavier one beforehand. Would be interesting

  36. So my light bike is about the weight of your "light" ones, but my heavy one is actually heavy, at a little over 20kg. Surprisingly, the speed differences on flat land is minimal, and in climbing I have Similar results as you guys, despite a much larger weight differential. So how does this really scale up? And what about riders' weight? I weigh in at 100kg

  37. The speed you lose from the climb from heavy bike is made up with the speed you go downhill. A heavier bike goes downhill faster than a lighter bike.

  38. my heavier bike (9k) is great at descending… due to the weight of course, but also due to the traditional chainring sizes on it, as apposed to my lighter bike with a compact set. I am very happy riding the backup bike; but yah, the lighter bike certainly climbs faster, and I love to climb.

  39. So… How about a 20kg bike? xD. I wanted to see how much faster(or not) I would be if I actually got a 6kg bike

  40. The heavy bike at 9.5kg is really not that heavy. Most bikes that cost about £1000 are that weight and that's alot of money for most people. To get your 7kg bike your looking at £3000+. Out of most people's ranges. Need more £1000 bikes in the videos!

  41. My old bike 17kg (It was heavier before I changed some parts eg the old handlebar was like a crow bar and about 5 times heavier than the new alloy one I added. New bike 11kg. Both hybrids for day to day practical use.I still like the stability & solidness of the old bike and I carry a rucksack with 5-10kg of shopping on my back regularly (plus there is me 105kg clothed), though not up a mountain but some hills. If the lighter bike was so much better I would have thrown the old one away. BTW old bike 25 yrs old. Steel frame Raleigh. I must admit on hills it is tough so I use a 28 -26 gearing for the worst. At the other end is a 48-12 and I daren't go any faster or the brakes might not stop me, especially in wet. I wear jeans and hike boots normally so a test of something like this compared to the latest and lightest might be of interest. I'm guessing approx 50% (maybe 100% with filled rucksack) slower or thereabouts but then I only need to go half as far for the same exercise. As long as it's enjoyable I'm fine with it but I might look at some new wheels for it next which might help. You could fly me to some exotic location and I'd give it a go. Oh I did adapt the Raleigh for some aero performance which proved quite successful but if you want to see that you know what to do.

  42. My altas bicycle weigh 20Kg steel. from india. This is only thing light to me. Also I have extra 20 Kg of luggage. So total my bike weigh about 40kg. I ride long distance. my bike cost about $100. I am not sure how can you call your bike heavy compared to mine.

  43. What about 2 bikes that weigh the same but the wheels are of different weight. How much does unsprung weight diff affect your performance.

  44. You say that your 35 second 2 percent saving isn't much but need to think that aero bikes with wheels etc that people bleat on sbout only improve over cheap non aero bikes by about 90 seconds over 40km at same power so you to gain 35 sec over 8km in 21 mins dhows that weight even on shallow 7 percent gradients just as important as being aero especially bearing in mind over most long runs many slopes and gradients that weight will be more of a factor than aero.

  45. If you're cycling to get fit and strong may as well get a stronger, heavier bike that will make you fitter and stringer and has far less environmental impact, last longer, wears better and will biodegrade faster once it's life is over.

Leave a Reply

Your email address will not be published. Required fields are marked *