How Much Does Weight Actually Matter On A Climb

We all know that weight makes a significant difference when it comes to how fast you can ride up a climb. The heavier you are, the slower you'll go for a given power. The lighter you are, the faster you'll go for a given power. How much faster or start, how much difference does weight actually make on a significant climb? We're about to find out. One of the great things about cycling is that so many different shapes and sizes can not only take part in it, but be really bloody good at it. If we look at the pros, Søren Varensholdt weighs in at 95 kilograms, whilst Lenny Martinez is just over 50. In many respects, it's quite incredible that they compete in the same sport, even if their strengths lie in different areas. The thing is, they all have to get over the same mountains in a grand tour. Today, we're going to look at how much difference weight really makes on a climb. To do that, we've come to the famous Coy de Ratas on the Costa Blanca in Spain. This is a climb rather than a mountain. It's six and a half kilometers long, with an average gradient of five and a half percent. The current KOM is held by Tadej Pogacar, who, yes, no, I hadn't heard of him either. He set a blistering time up here, under 12 minutes in December of 2025, which works out as over 32 kilometers an hour. That's over 20 miles an hour. Unbelievable. Now, we should point out, we are not trying to set any record on the Coy de Ratas today. We couldn't set any record, but we're not trying to either. Instead, we are going to use this climb for an experiment. We have gathered together 10 GCN presenters from the UK, Spain, Germany, Italy, and France. We're going to set off to gather up the climb, but rather than race each other, we are all going to hold a steady 250 watts. With our system weights, i.e. the weight of the presenter, their clothes, and bike combined, varying from 72 to 108 kilograms, we are expecting a difference of over eight minutes from the fastest to the slowest based on online mathematical models. This is the real world where math has no jurisdiction whatsoever. Well, it does, but we're just going to see how close it is to reality. Right, it's time for my crucial weigh-in. I weigh about 77 kilograms first thing in the morning in boxer shorts at the moment. We don't want to film that part, obviously, but with all this bike and kit, et cetera, I think I'm going to be probably close to 90. They're about 89.5. I've just seen Max being weighed, he's just 72. It's quite a big difference. The weigh-in showed a large range of system weight all the way from 72 kilograms for Max of GCN en France, right up to 108 kilograms for Giorgio of GCN Italia. 85.9. Weigh-in's done, it was time to set off. We knew who would be at the front and rear, but would the difference be as much as we thought? Three, two, one, go. I can't clip in. Matt Stephens. Inability to clip in quickly was not factored into the final results. Whilst we're talking caveats, I should also point out that we were not all using the same tires, so there was some difference in rolling resistance, and that the accuracy of most of our power meters was plus or minus 2%, so that too could have made a small difference to the end results. Anyway, it was no surprise to see Max at the head of affairs pretty quickly, despite the relatively shallow gradients at the foot of the climb. Already, gaps have opened up. Well, they had amongst most, but there was a cluster of us stuck together. Lauren and Patrick from GCN Auf Deutsch, Bernat of GCN en Espagnol, and me. Our system weights varied from 88 kilograms to 90, so only a couple of percent difference. It would be interesting to see if any gaps opened up as we hit the steeper gradients. Halfway up the climb, at least for Max, and the differences were far more pronounced. Max in front, Louis and Bernat together, despite a three-kilogram weight difference, then Oli, then my group, and finally the Italians bringing up the rear. Oli is not actually that far ahead, but I can't see Max, Louis, or Stephens. Despite Bernat's best efforts to get aero just as I got out of the saddle, there was still nothing to separate the four of us as we too reached the halfway point of the climb. I interrupt the Coelhorates climb briefly to deliver you some science. Basic science, but science nonetheless. Why is weight so important when you're climbing on a bike? Well, it's fairly obvious. It's because of gravity. On a flat road, the two primary things that prevent you from going faster are air resistance, i.e. pushing the air out of the way to move forward, and rolling resistance, the friction between your tires and the road surface you're riding on. As soon as the road gradient shifts into positive figures, gravity starts to come into play. On very steady gradients, it's not as noticeable, but it is still there. Even at 1% gradient, what we would describe as a false flat, around 25% of your power output is going towards overcoming the gravitational pull. That then triples to about 75% when the gradient steps up to 5%, which is roughly what we're tackling on the Coelhorates climb. Then once you get some more extreme gradients of 20% or so, which is roughly what you'd see on something like the Mour du Huy, over 95% of your power output is used to overcome that gravitational pull. This is why on flat road, your weight doesn't really affect how fast you can ride once you've accelerated up to speed. If anything, heavier riders who generally have a higher absolute power will be at an advantage. Once you're climbing though, the more the gradient goes up, the more advantageous it is to be lighter. Right, back to the climb. Alain, at 96 kilograms, had the second-heaviest system weight, and by two-thirds of the way up the climb, the difference between him and those at the front was minutes. It's not a big surprise given the science, but to see the differences play out on the road to that degree really put things into perspective. Giorgio, meanwhile, was even further back. 500 meters to the top. Somewhat unsurprisingly, the four of us who had a system weight within one kilogram of each other have been together all the way up, having a reasonably nice chat at 250 watts. Things have really stretched out to the others. We're all at the top now waiting for Giorgio. The prediction was that he'd be eight minutes down on laps. Here he comes now. That actually felt quite strange because when you're all lined up on a road like that and you're starting a climb, it feels like it should be a race. Even on the climb, it felt like it should be a race because I thought, I could go a bit harder and catch Ollie up, but you can't because you've got to stick to 250 watts, but it was interesting. Really, really interesting. I was surprised when I turned around and then saw you guys come in, four of you together, despite the fact that your weights were different, but your weights were- Only by about two kilos maximum, the difference between the group, I think. Yes, but I think what that shows is that there are other factors at play that aren't taken into consideration by the basic mathematical model that actually make up the difference in weight. For example, the drafting effect, even at modest powers on a climb like this for an amateur, is significant, as is things like rolling resistance. Yes, exactly. Do you know what? At the start, you obviously started to pull away, but not massively, not as quickly as I thought you were going to, to the point where I was back in race mode thinking, well, Ollie's not going to be much further ahead than us. Also, in that group towards the end, the other instinct towards the top here was, I'm going to have a sprint finish. You can't, you just roll across the line at 250 watts. We're not going to give too many of the numbers away because we're going to do that in the studio in a minute. I mean, not in a minute, obviously, it'll be in a couple of days for us, but it'll feel like a minute to you, or even less. That wasn't a minute, that was just a second. Anyway, here we are. Whilst that wasn't a race, I'd have finished much higher off if it was, obviously, I'm going to read out the final results. The fastest rider was indeed Max despite only averaging 242 watts on the climb. The online calculator that we used, mywindsock.com, predicted that Max would complete the climb in 20 minutes and 41 seconds. His actual time was exactly a minute quicker than that despite the lower average power. A reminder, his system weight was 72 kilograms. The next lightest rider, and therefore the next fastest, was Sebas. He averaged smack on 250 watts for a time of 22 minutes and 16 seconds. However, he was not alone. He got to the top with Louis of GCN En Francais despite a three kilogram difference in system weight, 79 kgs for Sebas versus 82 for Louis. As Ollie mentioned earlier, drafting does play a role at the speeds that we were riding. For Sebas and Louis, who rode the climb at around 18 kilometers per hour average, you will still save more than 10 watts by slipstreaming another rider. Exactly one minute slower than that, also with an average power bang on 250 watts, was Ollie. His system weight was four kilograms more than Louis. Then a further minute back, it was my group. Me, Patrick, Lauren, and Bernat. Our system weight varied from 88 kilograms for Patrick through to 90 kilograms for Bernat. Again, the drafting aspect was probably enough to keep us all together despite the slightly slower average speeds. With a system weight of around 18 kilograms more than Max, our time was four and a half minutes slower, a significant chunk of time on a 20-minute climb. Then at the rear, we had Alain and Giorgio of GCN Italia. Alain finished with a time of 27 minutes and 6 seconds, whilst Giorgio was 28 minutes and 55, almost bang on his predicted time on my windsock for his system weight of 108 kilograms. He averaged 251 watts. The difference of over nine minutes from the first ride to the last is big, a duration almost 50% extra, but also I would say it's expected. Max's power to weight was four watts per kilo, there or thereabouts, whilst Giorgio's was just 2.6 watts per kilo. We have proven a number of points today. Number one, drafting does make a difference on climbs, even at a relatively low power output. Number two, online climbing calculators are pretty bloody accurate. Three, weight does make a big difference on climbs, no huge surprise there. However, I really want to emphasize that this particular experiment does not tell the whole story. What it doesn't show you is that if this was a race, our heavier presenters could have produced more power than the lighter riders, at least for the most part. Not only can heavier riders with more muscle mass generally produce more power, they often come into climbs feeling fresher because they haven't had to work as hard to get there as the lightweight climbers. Whilst the temptation might be to go on a crash diet to lose weight, that is often not the answer. More and more, pro riders are fueling more and looking to be more robust, and more often than not, a stronger engine is going to be a lighter system. Right, let me know your thoughts. Did you expect the differences to be as big as they were? Let me know in the comment section down below, and I will see you all very soon.