A lighter bike will not make you climb faster

1. Here is a common question for the aspiring grimpeur: will a lighter bike help me to climb faster? You may be tempted, dear reader, to answer in the affirmative immediately, citing the laws of physics, received industry wisdom and good old common sense. However, what are these ‘laws’ anyway, is the bike industry so wise, and does common sense actually make any, er, sense?

The easiest way to answer the question is through a little test. First, we pose a hypothesis: lighter bikes climb faster heavier ones. Then we test it. Your author has already done this and through the marvels of Strava has a nice bunch of data for various climbs at his disposal. A good hypothesis should be falsifiable. And this one is. All we need is one climb where a heavier bike climbed faster than a lighter one. Yep, got a couple of those – your author riding certain climbs faster on his steel, 20lb+, 105-equipped, relaxed angles, 32-spoke wheeled ‘winter’ bike than his (very, very modest) ‘race’ bike. Falsified: lighter bikes do not climb faster than heavier ones.

But, but… come your protests, what about physics and force and mass and the acceleration of gravity? What about those laws? Very good point. Those laws have been pretty well tested and not (yet) falsified, so they certainly stand. So we have a problem. A lighter bike should climb faster in theory, but in practice this is not always the case (we can reverse the hypothesis above and get the result that heavier bikes do not climb faster than lighter ones). Why is this the case? Well, and certainly obviously, the bike is but one part of the climbing equation. There is the rider, the big, heavy engine of the bike who performs differently at different times. The rider is the variable.

Physics says that a lighter bike will climb faster all other things being equal. But those things are almost never equal. Even on the same climb, one has to factor in environmental conditions, variations in rolling resistance, whether you remembered to lube your chain on a different day, carrying two bottles or one, not to mention the performance of the rider – early or end of season, peaking or over-trained, carrying a little extra weight, riding alone or racing against others. If these differences between different rides are minimized, a lighter bike should climb faster, but these variables count for a lot – it really is all about the engine: the rider. The best hypothesis might actually be, bike weight is not the determining factor in how fast a bike (and rider) climbs a particular ascent. That might well be the best fit for the evidence.


There is a grand bargain in the bike industry that was established many years ago and has been refined subsequently. It goes roughly like this. Bike publications test bikes. They divide them into artificial categories based primarily around price, construction parameters, and groupsets. At present, this approximates something like: high-end carbon and Dura-Ace level = racer; high-end carbon but with less stiffness and Ultegra level = performance/enthusiast; cheaper carbon or aluminium/aluminum and 105 level = recreational or entry-level.

The publications then go on to extol the various performance characteristics appropriate to each level. At times, they get tangled in the much-mocked semantics of ‘laterally stiff but vertically compliant’ but at all times must conclude that race bikes allowed them to dive in corners without hesitation, while performance bikes allowed them to go on long rides but still sprint for sign posts, while entry-level bikes found the right balance between price and performance. Almost without fail, however, they are careful not to say too much outright that suggests that actual, rigorous scientific testing took place. Phrases like the following emphasize (apparently) perceptible differences rather than actual test results: “felt faster on the climbs”, or “felt surprisingly comfortable despite its quick handling”, or “the wheels felt heavy and I was left behind on the uphills.”

The older, venerable publications like Bicycling do not – most of the time – actually say ‘this is faster’. The problem is, hand on heart, they cannot say that. To do so would require the sort of testing that is impossible with bikes – double-blinds with control groups and measuring instruments and blah, blah, blah. Part of the problem is ‘framing’ – if you ride a $8,000 bike, you will feel faster because you expect the bike to be faster; you may even ride faster because you feel speedy and motivated and more confident. Or, you may have the perfect storm of conditions where you can realize the performance gains that different bikes can offer. This does not mean, in an objective sense, that a particular bike is faster. It has a potential for performance that you may or may not be able to realize.

Another part of the problem is that there are not huge gains up for grabs from certain bike parameters (see here for a full discussion, perhaps the only time that Karl Popper has been mentioned in a bike blog). Another aspect is that bike testers, conducting subjective tests, may not actually be able to physically discern different performance characteristics in bikes – they feel different (most of the time) but what that actually means is unclear. This is why many reviews are full of obfuscating language and also surprises – bikes perform better or worse than expected, performing like more expensive models (whatever this means), or their handling is not as quick but they offer a ‘damped’ ride that can still win a sprint. Reviewers have to write something, but in this day and age where we measure everything (watts, seconds, grams, gradients, miles and so on) these fuzzy words have no comparable meaning.

Let us be clear: there are things that can be measured and the things that can in theory but cannot in practice. There are differences between bikes that are important, and they are different from each other. However, in terms of actual performance – not just feel – those differences are notable but not always significant. And we know this. We as riders know it, bike journalists know it, and the bike makers know it. That is the grand bargain – we are all in on it. It is not a scam, it is just the nature of cycling. It does not stop us as riders wanting upgrades, even though we know the performance gains are mostly marginal and achieved only in perfect conditions. We read the reviews, nod and smile, but still put the bike on our ‘wish list’ nonetheless. These bikes and products are aspirational, they are not essentials.

It may be the case that this bargain is breaking down. Firstly, there are the reviews that claim objective performance benefits of some magnitude from certain bikes and gear – such as the infamous Cycling News review of hydraulic brakes where their ‘scientific’ testing was riding down the same descent a second time with the new brakes (wow, what rigorous methodology!). Peloton magazine has been another perpetrator of such reviews, one of which was lampooned here on this blog, with bold claims of objective gains that simply collapse under any decent scrutiny. Bicycling magazine is on thin ice, too, with recent reviews like, “…I could dive into corners later…” (really, later than what – another bike; if so, which one, and how much later?). Or, “…the bike was stable enough that we could sit up and remove a jacket…” (what does this mean, that other bikes are not this stable – surely if you have the balance to do this you can do it on any bike?). It is a concern if subjective claims are giving way to supposedly objective ones with little evidence to support them. Should we worry?


At some point in time, every rider makes their own deal with the seemingly inexorable march of technological improvements. This deal might take on one of the following possibilities: first, new technology is embraced and adopted for its performance-enhancing potential; second, new technology is appreciated for its design and aesthetic innovation but not seen as a tool for speed; third, new technology is an aspirational or positional (or even status signifying) product that is adopted as part of a ‘progression’ or a reflection of riding stature; fourth, new technology is largely ignored until it trickles down (10-speed Tiagra becomes the new 105, 105 is the new Ultegra, Ultegra is now Dura-Ace, Dura-Ace is for pros only); fifth, a curmudgeonly approach is taken where new technology is seen as largely superfluous for the majority of riders and a hindrance to practical riding (another proprietary 11-speed chain and cassette means being locked into a pricey and frequent replacement process).

Within this schema, most riders likely make a calculation as to how much they are prepared to spend, what frame material they prefer, their ideal number of gears, and any other number of choices for equipment. Bike choice, groupset and other accessories are chosen either for what they might do (performance), how they might make the rider feel (the ‘feel’ of Titanium, for example), what it represents (Italian design, for example), or encompassing a particular philosophy of riding (new technology adopted because it represents progress). Racers might want the latest and (supposed) greatest but might also take pride in doing more with less. (Cosmo Catalano has written more eloquently and with more cutting wit than your author on some of these ideas and is well worth reading on the subject.)

Other riders become less interested in the bike and more in other products. Once a capable, functional and reliable bike has been secured, and that bike has proven to be versatile and durable, items like a better rain jacket, more comfortable shoes, or a better range of base layers for all riding conditions become more important. The focus of bike performance shifts to looking after the engine – the rider – rather than fussing over the minor details on the bike. There is also the placebo effect. Try it – if you really want to go faster on your next climb, put some fresh, white bar tape on. Yeah, it looks pretty fast, doesn’t it!

We cyclists have an odd relationship with technology. Eddy Merckx’s quote is well over used but perfectly encapsulates this whole argument: don’t ride upgrades, ride up grades. Focus on the rider, not on the bike. Yet Merckx was fastidious over his bikes, taking multiple models to his races, each with a slightly different set up. He had special frames built for him and was always tinkering, and he was supplied with the latest technological innovations of his time. He rode both upgrades and up grades.

None of us are Eddy Merckx. Still, it is easy to get fixated on new bikes and new technologies for the wrong reasons, thinking that they are a pathway or a progression to higher performance. In the perfect setting they can be – a lighter bike will climb faster, all other things being equal – but realizing those gains is not always possible. The bike industry is superb at offering us the latest innovations and there are many reasons why we will adopt them (or shun them as we choose). It is not particularly good, however, at explaining to us just what those innovations can offer us. Your author could be wrong, not having ridden nearly as many bikes as the test teams of prominent cycling publications. But common sense suggests that we as riders are not always attuned to the tiny differences that many bikes offer.

If it were possible, those would be good hypotheses to test – to get some real rigour into bike testing and all the claims that are made. But does it really matter? We are enamoured by numbers at present, tracking and analyzing them and comparing them. But riding is all about sensations and finding the bike that works best for you on this basis is all that is really needed. The ride can be so much more than just a collection of statistics. Still, it never hurts to make comparisons, because we are relentlessly troubled by nagging questions. One might wonder, “will these wheels make me climb faster?” They might, but then again they might not. When you’re deep into your reserves, fighting up a climb, the biggest determinant of your speed might be whether you have the mental and physical fortitude to stand up on the pedals and shift into a harder gear and push yourself that little bit more. At this moment in time, the bike you’re riding makes very little difference.

Said JJ Rousseau, "To be and appear to be, became two things entirely different, and from this distinction arose imposing ostentation, deceitful guile and all the vices which attend them." Whatever.
Said JJ Rousseau, “To be and appear to be, became two things entirely different, and from this distinction arose imposing ostentation, deceitful guile and all the vices which attend them.” Whatever.

Something that might actually help you climb faster is training. Don’t forget that there is a giveaway going on (which will run for a couple more weeks). See right here for all the details.

6 thoughts on “A lighter bike will not make you climb faster

  1. Weber’s law states that the “just noticeable difference threshold between two stimuli is proportional to the magnitude of the stimuli. What does that mean?

    Let’s break it apart. The “Just noticeable difference threshold” is a the difference between two stimuli that can be RELIABLY detected by a human. Is this thing heavier than this other thing.

    The “proportional to the magnitude of the stimuli” means that as a given stimuli gets heavier, the just noticeable difference threshold gets larger.

    For the ability to tell the difference in weight between two objects, the just noticeable difference threshold is about 5%. At 20lbs, that means the threshold is 1lb.

    Thus a blindfolded person could not even reliably tell difference between a 19.1 lb bike and a 20lb bike when lifting it, much less riding it.

    So in some ways I see the point.

    But in other ways, the author is guilty of the same sin as the bicycling magazines. Yes Karl Popper introduced falsifiability into the lexicon of deductive science, but science is also about repeated measurements, and an explicit acknowledgement that measurement is always accompanied by some degree of error. To highlight the fact that two performance distributions overlap, i.e., that some values on a heavy bike exceed some values on a light bike may negates the hypothesis that the lighter bike is ALWAYS faster, but that’s kind of a silly hypothesis to begin with given that the author notes that individual human performance is variable.

    The author is no more scientific in his rebuttal of magazine claims than the magazines themselves are in making the claims. There is no real data presented to support the argument that with repeated measurements a heavy bike is faster than a light bike on a climb. We have some bad statistical practices that compare the outliers of one distribution (i.e., the fastest times on the heavy bike) with the outliers of another distribution (i.e., the slowest times on the road bike) and negate the central tendency of each distribution when it is the central tendency, not the outlier, that makes up the hypothesis “lighter bikes climb faster heavier ones”. We don’t even know the difference in weight between the author’s road bike and his winter commuter.

  2. The title of your article is a lighter bike will not make you climb faster, yet you list the variable “carrying 2 bottles or 1”
    Weight = weight. If you want to make the case that it’s the rider, then make it, but don’t cite weight in another way when you’re trying to dispel non-rider weight as a variable when climbing.

  3. Time Trial up a hill on your favorite bike, then strap on an additional 100 lbs and repeat. Compare results. I’ll bet your first time is faster.

  4. If the combined weight of rider and bike is less you will go up hill faster… fact.

    The cheapest way to get weight off this combination is by eating just less than you need for your training, and train hard up hills!
    I’ve lost 10lbs in a few weeks and I’ve ridden 250 miles a week. Its not the most but i certainly go up hills faster now.

  5. I think the ultimate point is that the gains are minimal for most leisure cyclists. Yes, add 100 pounds weight and you will be faster. Yes, lost weight yourself (without muscle loss) and its the same as losing weight off the bike. For elite athletes this is important, but for most of us more improvement gains will be made by training rather than losing a pound or 2 off the bike.

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