{"id":53,"date":"2020-04-20T09:08:09","date_gmt":"2020-04-20T16:08:09","guid":{"rendered":"http:\/\/bestrides.org\/manual\/?page_id=53"},"modified":"2023-10-16T09:27:42","modified_gmt":"2023-10-16T16:27:42","slug":"components","status":"publish","type":"page","link":"http:\/\/bestrides.org\/bikeschool\/?page_id=53","title":{"rendered":"Components"},"content":{"rendered":"\n
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Asked of a rider with a 12-speed cassette: Why do you have 12 speeds? <\/em>
Answer<\/em>: Because I can<\/em>. <\/p>

\u201cLaterally stiff, vertically compliant\u201d (The mantra of all bicycle engineers)<\/p><\/blockquote>\n\n\n\n

When you buy your first bike, you think of it as a bike. But soon you come to think of it as a frame on which someone decided to hang certain parts. And you can change every one of those parts, to something better, lighter, or just more to your taste. In this chapter we\u2019ll talk about the parts that make the bike go (the components<\/em>\u2014chains, handlebars, tires); in the next chapter we\u2019ll talk about the parts that aren\u2019t part of the bike but that support the riding (the accessories<\/em>\u2014computers, rain fenders, water bottle cages). In these two chapters we\u2019ll just talk about the issues you face when you\u2019re shopping for the parts; we\u2019ll talk about each one again focusing on how to take care of them in the In the Garage<\/strong> chapter.<\/p>\n\n\n\n

Not every item in this chapter is something you want to think about at the beginning of your cycling career, but every one is something you will want to think about eventually, because the components on your bike will wear out and you have to replace them, at which point you\u2019ll have to decide, Do I want something different? Do I want something better? And some component issues you want to think about before you buy the bike, so you can discuss a gear swap with your bike shop before the purchase, specifically the cassette, the chain ring, the handlebar, the stem, and the pedals.<\/p>\n\n\n\n

I\u2019m going to repeat three things I said in the Buying a Bike chapter:<\/p>\n\n\n\n

1. There are no scams and no steals in the bike industry. All bike components from reputable manufacturers are made with integrity and sold for what they\u2019re worth. Anything that doesn\u2019t do what it\u2019s supposed to do doesn\u2019t stay on the market long. So don\u2019t worry about being cheated, and don\u2019t expect to get top quality at a bargain price, unless it\u2019s openly on sale.<\/p>\n\n\n\n

2. Learn to use internet reviews. Pretty much every component of interest to road riders has been reviewed online within hours of it hitting the market by scrupulous, tech-savvy rider\/critics at sites like bikeradar.com<\/a>. Benefit from their expertise, take their advice. Just search for the component you’re interested in and add the word “review.”<\/p>\n\n\n\n

3. Be cautious about buying exotic components. High-end components and components from small companies often use proprietary<\/em> elements\u2014parts used here and almost nowhere else. And the more you pay for a component, the more likely it is to have proprietary elements. The benefit is, the proprietary part was created for this application, so it should work really, really well. The drawbacks are extreme: you can\u2019t find replacement parts in any bike store that doesn\u2019t sell that brand, you can\u2019t expect a mechanic to be able to work on the component if it needs repair unless they’ve been trained by that company, and as soon as the component becomes out of date the company will stop making it and when it breaks you won’t be able to replace it and you may have to throw away much or all of the bike. <\/p>\n\n\n\n

Three real-world examples: 1) There are German bicycle wheels whose parts are so exotic the wheels have to be mailed back to Germany to the factory for any<\/em> repair, so you\u2019re wheel-less for 6 months; 2) I bought brakes from a well-respected but small company, and they never worked right. I happened to run into the company\u2019s tent at a bike fair and had the company wrench work on the brakes. They worked perfectly. I asked him what he did that was so special, and he said, \u201cMost shops just don\u2019t know how to work on our brakes\u201d; 3) I once had a mountain bike that broke a seal in the front fork. The seal probably cost 50 cents, but the fork was old so the company had stopped making the proprietary seal. I ended up having to replace the fork, the brakes, and the wheels. <\/p>\n\n\n\n

So you\u2019re safer buying components from huge, successful companies, components that are used in lots of different bikes, because the companies will be around for a while and repair shops everywhere will be familiar with their products.<\/p>\n\n\n\n

Gravel Components<\/strong> and Accessories<\/strong><\/p>\n\n\n\n

Because gravel riding is the hot new thing, and because marketing is what it is, gravel bikes have their own components and accessories\u2014gravel-specific derailleurs, cassettes, shifters, wheels, handlebars, shoes, and so on. I’m going to talk about road components only in this chapter, but the differences between road and gravel components are usually minor (and some say gratuitous). In general, gravel-specific equipment will be stouter (to withstand the rigors of off-road), bigger, heavier, wider, and softer (more compliant, to smooth out the bumps). The three major differences are 1) gravel bikes have single chain rings instead of doubles; 2) gravel bikes have lower gearing, to handle the steep pitches of dirt roads and trails; and 3) gravel bikes have much bigger tires\u2014as big as 42mm, compared to a road bike’s 25mm or 28mm.<\/p>\n\n\n\n

Components One at a Time<\/strong><\/p>\n\n\n\n

Wheels<\/strong><\/p>\n\n\n\n

Cyclists dream about upgrading their wheels. There are more companies focused on selling wheels than any other component. A wheel upgrade is always the first improvement a rider makes to their bike, for two reasons: 1) the bang-for-buck improvement in performance is greater than with any other component, and 2) if you buy a good bike, the wheels are often the cheapest component in the mix, because bike makers often assume that riders will have wheel preferences and will replace the stock wheels anyway.<\/p>\n\n\n\n

Wheelsets<\/em> (wheels in pairs, which is how they\u2019re always sold) used to be easy to shop for. All wheels used the same technology, and the more you spent, the better the wheel. So you could settle on a price range and buy any wheel in it from a reputable maker. But wheel shopping has gotten complicated in recent years, because manufacturers now make (at least) three different styles of wheel-to-tire interfaces: traditional (with inner tubes), tubeless, and hookless. We’ll talk about the benefits and drawbacks of each.<\/p>\n\n\n\n

Traditional<\/strong>: the wheel rim has a sidewall, and the top of the sidewall has a lip, called a “hook.” The tire has a bead along its edge, and the bead fits under the lip, so the lip holds the tire to the rim. Inside the tire is an inner tube. As the name implies, this system is the oldest of the three, and some people consider it out-dated. Its advantages: the tire is held very securely, you can use very high tire pressures, and tire changes on the road are relatively easy. Its disadvantages (according to some): the wheel and tire are heavy and the system is less aerodynamic.<\/p>\n\n\n\n

Tubeless<\/strong>: as the name implies, this system has no tube. In theory, the tire fits snugly enough to the rim to hold air all by itself. Typically you add a slime to the inside of the tire to plug small punctures. Its advantages: it’s nearly puncture-free and it eliminates the weight of the tube. Its disadvantages: the tire can be very hard to get on and off the wheel; slime is messy and difficult to install; slime has a short lifespan and has to be replaced; ; the tire has to be heavier to withstand the air pressure; you can only run lower tire pressures. See the lengthier discussion under “tubeless tires” below.<\/p>\n\n\n\n

Hookless<\/strong>: this is the newest and most controversial technology. As the name implies, the rim has no lip, and so the tire has no bead. Its advantages: the wheel is lighter, and the wheel\/tire interface is more aerodynamic. Its disadvantages: the tire is less securely stuck in the rim, so you can only run very low tire pressures\u2014most hookless tires have a max pressure in the low 70’s\u2014and (some say) there is still a danger of blowing the tire off the wheel. Hookless tires are also tubeless.<\/p>\n\n\n\n

Which should you choose? The traditional wheel is the safe bet\u2014it’s bullet-proof and dealing with flats is easy. Tubeless is “happening” (as of 2023), and your local bike shop will probably push it as a defense against flats and as a way to run lower tire pressures. Hookless is at this moment still somewhat of a gamble. Both tubeless and hookless are promoted as enhancing performance (making you more aero or lighter, therefore faster), but the performance gain is negligible unless you’re racing.<\/p>\n\n\n\n

Beyond that issue, you can think of wheels in terms of seven criteria: weight, stiffness, comfort, aerodynamic shape, quality of hubs, rim width, and construction material.<\/p>\n\n\n\n

Weight<\/strong>: The easiest criterion to understand is weight. Light wheels are not necessarily better than heavy ones\u2014they\u2019re faster on steep pitches, and they accelerate faster, but there\u2019s no real advantage on the flats once the bike is up to speed, and lightness is actually a drawback on descents. Lab tests now tell us that a wheel’s aero-ness is more important than its lightness, even on moderate climbs and at slower speeds, and pro racers are starting to use their deep-section wheels on climbing stages, but lightweight wheels are still most cyclists’ fantasy.<\/p>\n\n\n\n

Stock inexpensive wheelsets weigh about 1800 grams, without skewers, tires, or tubes. Mid-range wheelsets weigh about 1600 g. Wheelsets start being considered light around 1450 g, and anything much under 1400 g is very light. The grams you save buying light wheels are also among the cheapest weight savings on the bike\u2014you can save almost a pound of weight over stock entry-level wheels by spending $700. Since the lost weight is rotating weight<\/em> (weight you have to turn in circles), the effect of the lost weight is greater than if you lost it out of the frame, and the bike accelerates faster. To find out what a wheelset weighs, you have to weigh it\u2014riding won\u2019t tell you, and manufacturers\u2019 claims can\u2019t be trusted.<\/p>\n\n\n\n

Carbon is lighter than aluminum, so carbon wheels should be lighter than aluminum ones, but wheel makers take advantage of carbon\u2019s light weight to make the rim deeper (see Aero discussion below). Aluminum rims are about 15 mm deep, but carbon rims can be as deep as 80 mm. That’s a lot more mass, so the weight of a carbon wheelset is often about that of an aluminum one. If you value light over aero, get carbon wheels that are shallow (25-40 mm).<\/p>\n\n\n\n

As we said above, tubeless wheels\/tires are a bit lighter than traditional set-ups, hookless lighter still.<\/p>\n\n\n\n

Stiffness<\/strong>: Wheels need to be stiff laterally (side to side), so they\u2019ll hold a line and track through a corner securely. And there\u2019s the first double bind that wheel makers find themselves in. It\u2019s easy to make cheap, light, flimsy wheels, but to get something that\u2019s both light and stiff you need to be a good engineer and to spend a lot of money. To tell how stiff a wheel is, ride it down the road and shake the handlebars back and forth. Any wheel will wobble, but a stiff wheel will wobble much less than a flexy one. Or, more subjectively, descend through a series of tight turns and see which wheelset makes you faster, more solid, and more confident. The deeper the rim, the stiffer the wheel.<\/p>\n\n\n\n

Comfort<\/strong>: A wheel that is stiff all over will beat you to death. So here\u2019s the wheelmakers\u2019 second double bind: how to built a wheel that is stiff side to side, for control, but has some cush up and down (compliance<\/em> in the trade), so every wrinkle in the road isn\u2019t transmitted directly to your teeth. To judge vertical compliance, just ride over rough terrain (railroad tracks are ideal) and see how much jarring you feel. The deeper the rim, the more jarring the ride. Aluminum is more jarring than carbon.<\/p>\n\n\n\n

Since lower tire pressure equals greater riding comfort, tubeless and hookless wheels\/tires are more comfortable because they allow you to run lower pressures.<\/p>\n\n\n\n

Aero<\/strong>: Next you want the wheels to be aero (aerodynamically efficient), so they slice through the air with minimum disturbance and reduce drag. Aero-ness is largely determined by the depth of the rim\u2014the thickness of the rim when viewed from the side. The deeper the rim, the more aero the wheel (there are other factors, but they\u2019re subtle). Rims range from 15 mm (not aero at all) to 80 mm (very aero), and there are event wheels for time trials that are solid discs (maximally aero). 50 mm is considered the beginning depth for meaningful aero, and anything 50 mm or deeper is called deep-section<\/em> or just deep<\/em>.<\/p>\n\n\n\n

Aero wheels have to use expensive materials to keep the weight manageable. Almost all non-aero wheels are made out of aluminum (\u201calloy\u201d in the trade), whereas any aero wheel that doesn\u2019t want to weigh a ton will have to be made out of carbon fiber. And carbon fiber costs a lot more than aluminum. A decent aluminum wheelset can be had for $500. A good carbon wheelset will cost you $2000 and up. To test how aero a wheel is, all you can do is ride down a straight, flat road and see how fast you can go. Aero wheels should gain you 3-5 mph.<\/p>\n\n\n\n

Aero involves the wheel-maker in a third double bind: the more aero a wheel gets, the more susceptible it is to lateral wind forces. You wouldn’t think it would matter that much, but it does\u2014a deep-section wheel will blow you all over the road in a crosswind. On a gusty day, pros often have to forego their deep-section wheels in order to stay upright. So engineers have to do amazing and expensive things to the shape of a deep rim to minimize wind effects.<\/p>\n\n\n\n

Hookless wheels\/tires are more aero than other types, because the tire is shaped more like a U and less like a lightbulb, thus allowing air to flow more uninterruptedly over the tire\/rim joint, but the gain is miniscule.<\/p>\n\n\n\n

Hubs<\/strong>: You want a good hub, which really means good bearings. Bearings are something cyclists don\u2019t shop for by name; instead they buy hubs with high price tags and good reputations\u2014Chris King, Tune, DT Swiss, Cane Creek, or any of the familiar components makers\u2014Shimano, SRAM, and Campagnolo\u2014and assume the bearings are good. Good hubs are one of the easiest elements on a bike to demo\u2014just ride the bike down the road. Just coasting along should make you say \u201cAhhh.\u201d It\u2019s wise to ask the seller of any bike you\u2019re thinking of buying, \u201cWho made the hubs?\u201d<\/p>\n\n\n\n

The quality of a hub is almost entirely the quality of the ball bearings inside it. Stock bearings, even in high-end hubs, are stainless steel. For $100-200, you can upgrade to ceramic bearings<\/em> (either by ordering your wheels with them or replacing the stock bearings after purchase). They roll easier, though the difference is slight (and in the opinion of some, all in the head). Spring for ceramic bearings only if a) you\u2019re interested in pursuing every performance advantage, however minor, or b) it\u2019s fun to know you\u2019re riding on the best. You also have bearings in your bottom bracket and your jockey wheels, and you can replace them with ceramics as well, but the performance gain is even smaller in those places.<\/p>\n\n\n\n

Rim width<\/strong>: You want a wide rim, because wider rims make it easier to run bigger tires, which have a lot of advantages (see Tires below), and they give tires a higher-performing profile (square instead of light-bulb-shaped). The old rim standard was 15 mm; then the norm became 17; now (in 2020) it\u2019s more like 19, moving toward 22, with some road wheels experimenting with rims up to 25 mm. Some wheel makers are going to an incredible 40 mm for gravel bikes. This matters, and if you’re planning on running big tires (bigger than 28mm), it’s crucial, because big tires on narrow rims have an inefficient shape. Don\u2019t bother to test-ride wide rims\u2014you won\u2019t feel the difference.<\/p>\n\n\n\n

Rim width is made more complicated by the fact that the industry uses “rim width” to mean two different measurements\u2014inside width and outside. Inside is all that matters, and the numbers above are all inside widths. Make sure any conversation about rim width is talking about inside numbers.<\/p>\n\n\n\n

Material<\/strong>: All cheap-to-moderate wheels are made out of alloy. But at the high end\u2014$2000 to $3500\u2014wheels are made out of carbon. Few recreational riders use them, but they are worth your serious consideration.<\/p>\n\n\n\n

Let\u2019s list the arguments against carbon wheels, with my rebuttal following in parenthesis:<\/p>\n\n\n\n