Updated: March 8, 2021
Is your overweight bike making you depressed? You’re not alone. Many cyclists dream of having the lightest bike possible. It’s the primary motivation of "weight weenies," people who count grams obsessively.
When it comes to improving a bike’s performance, weight is tangible. We feel it every time we pick up a bike. We can put a bike on a scale, get a number, and determine that a smaller number is “better.” We can spend money on new components that save more weight. As consumers, we have an ability to control and modify bike weight in ways we can’t with other aspects of bike performance like stiffness, aerodynamics, or geometry.
This Specialized S-Works Tarmac comes in under 15 pounds. Will it make you faster though? | Photo by Matt Jones.
But does bike weight really matter? Weight weenies would say yes. But the real answer is far more nuanced. In reality, weight is only one factor of many that affect bike performance. It may surprise you to learn that it's also rarely the most important factor. Let’s take a deep dive into the subject of bike weight and look at the costs, value, and what real riders think about saving weight on their own bikes.
The high cost of lightness
Rocket scientists are perhaps the world’s ultimate weight weenies. When sending objects into space, they deal with a problem known as the “tyranny of the rocket equation.” As the amount of weight they want to move increases, the rocket fuel required to do so increases exponentially. For example, increasing the payload of a rocket by only 5% may require a massive 130% more fuel to move it. Because of this problem, minimizing rocket weight is paramount. Aerospace materials are made to be as strong and light as possible to balance out the equation, and they’re hugely expensive because of it.
Of course, bikes aren’t rockets, but plenty of riders treat them like they are. Trimming off excess weight can become an obsession. Some riders might begin to believe that a matter of a few grams will be the difference between a great bike and a mediocre bike. Or winning and losing. An inconsequential component might go under the microscope and hundreds, maybe thousands of dollars could be spent to save less than a pound.
Take the water bottle cage for example. A metal bottle cage might weigh only 30 grams more than a carbon one. But the carbon cage will cost significantly more. You might spend $70 for a carbon cage versus $10 for a metal cage. Say you have a fairly light, 17-pound road bike. If you choose the carbon bottle cage, you’re spending seven times more money to shave off a negligible amount (0.4%) of your bike’s total weight. The math is similarly bad for most of the other components that can be upgraded.
It's bad for complete bikes too. For example, a top-of-the-line Specialized S-Works Tarmac retails for over twice as much as a similar Tarmac Expert. This higher price gets you a lighter frame and lighter components. But the S-Works model is not twice as light. The weight difference is only one or two pounds. You’re paying over 130% more, to save about 5% of the total weight.
This could be seen as the "tyranny of the bike equation." As bike weight decreases, the cost of increases exponentially. Being a hardcore weight weenie not only requires a lot of dedication but also a lot of money.
The value of a light bike
But is spending money to make your bike lighter worth it? It’s hard to say exactly when reducing a bike's weight actually becomes noticeable. You could probably tell if your bike suddenly became 10 pounds lighter, but would you notice if your bike became only one pound lighter?
The water in a small 20oz bottle weighs a little over a pound. Do you ever notice if you’re riding with a full versus an empty bottle? If not, then you probably won’t be able to tell that a pair of carbon handlebars are 100g less a pair alloy ones. It will take a lot of component upgrades throughout a bike and a lot of money for all those saved grams to add up to a meaningful reduction in overall weight.
But even if small reductions can’t be felt, the fact is that a lighter bike requires objectively less power to move. Especially on climbs, the power-to-weight ratio of bike and rider plays a huge part in overall performance. Even if it’s a small difference of only a few watts, it could matter in a race situation. Take two riders with the exact same fitness and body weight. The rider with the lighter bike will hypothetically make it to the top of a climb first, or they’ll have to expend slightly less power to reach the top at the same time.
There are limits to this, however. Rider weight is far more important in the bigger picture because riders far outweigh their bikes. A 180-pound rider on a 20-pound bike results in an overall weight of 200 pounds. The rider is 90 percent of that weight. This is why really good climbers are generally skinnier or smaller than average riders.
Decreasing bike weight can only go so far. Bigger gains are likely to be found when addressing aerodynamics, but that is a whole different topic.
The best lightweight bike upgrade
If you are going to spend money on a single weight-saving upgrade for your bike, wheels are the number one improvement you can make. They’re generally considered the best place on the bike to shed grams because wheels and tires are rotating weight. Additional weight increases inertia and wheel inertia matters a lot in cycling because the rider has to overcome it to accelerate. Heavier wheels require more energy to overcome this inertia. Many riders, even novices, can actually feel the difference when riding lighter wheels. They make a bike feel noticeably snappier and easier to get up to speed.
Carbon wheels are one of the most popular aftermarket upgrade options for both road and mountain bikes. Carbon fiber is exceptionally light, stiff, and strong. Because of carbon’s strength to weight advantage, road bike rims can be made deeper, wider, and more aerodynamic, without a massive weight penalty. Independent testing over recent years has shown the aerodynamics of a wheel to be of equal, and sometimes greater importance when riding on the road.
Upgrading to a wheelset that is both lighter and more aerodynamic is the ultimate win-win.
Do you need a lighter bike?
So who actually “needs” a lighter bike?
Riders who are already exceptionally small, light, and fit will enjoy the most benefits. If you are near peak fitness, then losing additional weight off your body could be detrimental to your power output or even dangerous to your health. The only option for improving power-to-weight is to reduce the weight of the bike. The lighter you are, the more small reductions in bike weight will benefit performance.
But for normal riders with average bodies, it’s always much more effective and affordable to reduce body weight and increase fitness. The number-one factor in performance is always the rider.
If you simply like the idea of having the lightest bike possible, and you can afford to buy an ultra-light, high-end bike or a slew of lightweight upgrades, then go crazy. Light bikes are cool, and there’s nothing wrong with that.
Just knowing you have a lighter bike could also help you mentally. Aerodynamics and fitness are important, but the mind also plays a huge role in performance. The belief that your bike’s weight is an advantage can give you a bigger advantage than the weight actually does on its own.
Durability and reliability are also important factors to consider. Lighter weight often coincides with reduced durability. The average weight for the bikes used by enduro mountain bike pros is over 30 pounds. This is significantly heavier than your average XC mountain bike. These types of bikes have to survive rough riding conditions. Running a lighter, more delicate frame or components will increase the risk of race-ending damage. In all forms of riding, adding weight to a bike is the trade-off you must make for increased robustness and reliability.
Even if you’re not racing, durability should be considered, especially when you aren’t a professional rider with access to a supply of replacement parts and skilled mechanics who can service and repair your bike. An ultra-light bike is cool, but it’s no fun having to make emergency repairs on the side of the road or end a ride prematurely due to equipment failure. This is especially true of tires. Lightweight, less puncture-resistant tires are better saved for race day when it really matters.
The takeaway here is don't worry so much about how much your bike weighs. If you have a light bike, that's good. If you don't, that's also fine. Make sure your bike fits your budget and is reliable to ride. Invest in your fitness, and if you can spend some money, get nice wheels.
What Riders in the Shop Think
Our shop is full of riders who obsess over their bikes and have access to a huge selection of high-end pre-owned products. Everyone’s been tinkering with their own set-up for years and they each approach bike weight in different ways. Here’s what they have to say.
Axel V., Purchasing Associate - “I train on my race bike, and when it’s set up for training it weighs 22 pounds. It’s heavy compared to most high-end road bikes, but I’ve never wished it was lighter. I prioritize durability, and the heft means it’s sturdy and it’ll keep going no matter the riding conditions. I don’t like to break things. Flat protection is key so I’m running heavier puncture-resistant tires and tubes. If you flat, you’re not riding! I’ll put carbon race wheels on for race days only. They make the biggest difference and on my bike, it’ll shed three pounds where it really matters. But only for those special occasions.”
Asher R., Bike Technician - “My mountain bike is 33.5 pounds. I think a bike should weigh as much as it needs to be durable. When you try to save too much weight you start compromising on durability, and you start spending lots of money when parts fail. The way I ride, I do notice the weight on climbs, but once I point my bike downhill I can go as hard as I want and it’s all worth it. Saving weight is a good thing, but save your money too. If you ride hard things will break. Durable, light, or cheap — you can only pick two.
Pete K, Bike Technician - “Racing at the pro level, weight is something you definitely think about. Where I’m at now, it’s easier to take the weight off my bike than my body. If an XC bike is over 24 pounds it feels pretty ridiculous, like it can’t go uphill fast. It’s like wearing a backpack. But I wouldn’t say I’m even the craziest one out there. I do care about durability and performance a bit more than weight. I did run a dropper post all season. The bike rides so much better with it. You have to be selective.”
Richard S., Merchandising Associate - “I’ve definitely gone down the weight weenie rabbit hole. I’m a climber so I think about it a lot. I’ve bought certain components when they were the lightest, even if they weren’t the best. I built up a bike that was around 14 pounds already but then I added Lightweight wheels and got it down to about 13 pounds. Once the bike got that light I could definitely feel the benefit uphill, but it lost so much stiffness and responsiveness. Then I had a bad crash and destroyed a lot of parts. It was a super expensive crash. My current bike is heavier, but I’m actually going faster now than I was before because the new bike is so much stiffer and more aero.
Steve G, Shipping Manager - “For me, it’s all about reliability and durability. When you ride deep into the backcountry, you need to know that your bike is going to make it back out. My mountain bike is 37 pounds. It’s the heaviest bike in the shop, but the geometry actually puts me in a good climbing position and that makes a difference. I keep up with everyone just fine. I haven’t had a flat or mechanical all season. There’s a time and place for light parts, XC racing probably. But when you’re riding long distances far from home you shouldn’t skimp.