Compact chainset why

Compact cranks have a smaller BCD, mm, which allows for smaller chainrings. Compact cranksets are preferred for climbing races or for people who like to ride fast but not race. There are many people that race compacts, but for most people it's not the preferred crankset for flatter races or any with limited climbing.

Combined with a wide-range rear cassette, like an , compact cranksets offer a wider range of gearing and -- as mentioned earlier -- are really designed to maximize one's efficiency to climb or travel at lower speeds. More recently, long-caged rear derailleurs have been more common in use with compact cranksets and cassettes, such as SRAM's WiFLi system. Standard cranksets have more gearing overlap, which can be preferred for racers so they have similar options in the middle of the cassette for both chainrings.

This allows for things like shifting into the big ring early if they think an attack might happen so they're prepared to jump to faster gears. Conversely, they can be going at a pretty fast speed in the little ring when approaching a climb and shift to easier gears as necessary. Racers have a tendency to want more options in a certain range of gearing; that's also why some racers elect to use an close range cassette instead of something with a wider range, because the gap between gear choices is smaller for certain shifts.

This makes it easier to maintain a preferred or optimal cadence which maximizes efficiency. Top speeds A standard tooth chainring paired with an tooth rear cog fastest rear gear gives speeds as follows when using a standard x23 tire. All of the speeds were calculated using a free software app from Bareknucklebrigade called Rabbit.

In the same table we'll compare the fastest combination for a compact crankset, a tooth front matched with the tooth rear. As you can see in the table, very high speeds can be obtained with a standard crankset, but you can still get moving right along with a compact crankset. Most people are not going to be able to travel at those speeds riding solo, so a compact is a good choice for those who do a lot of solo riding.

You will also notice that at rpm you're only giving up 2. Pedalling down a hill or in the final sprint of a race is when this would become a factor. Most people would have stopped pedalling at this point and would just enjoy the free speed. At least one study found that increasing cycling cadence benefited subsequent running performance.

But the research is conflicting with other studies finding that a lower cadence benefits running or no relationship between cadence and running performance.

In summary, a higher cadence may improve your off-the-bike running and you should experiment to find out. Compacts are lighter due to the smaller spider, smaller chainrings, shorter chain and potentially smaller cassette. All of these factors could add up to a modest weight savings of grams or more. Compacts may facilitate shorter cranks. There has been a trend towards shorter crank arms among triathletes and time trialists, primarily to allow a lower and more aerodynamic position by opening the hip angle.

This, in turn, can lead to improved off-the-bike running. While crank length remains controversial, some studies have shown that its effects on power output or metabolic efficiency are small or insignificant.

Assuming this is the case, cyclists are free to choose crank length based on comfort and aerodynamics. With shorter cranks, some cyclists will naturally choose a higher cadence. However, the opposite may be true for cyclists who do not increase their cadence after switching to shorter cranks.

Bike fit guru John Cobb made this rather counter-intuitive observation:. Unfortunately there is no obvious conclusion regarding crank length and gearing. Yes, aeroweenies think like that. There is an unfortunate stigma attached to compact cranks—the idea that they are the wimpy option for weak cyclists.

Snobby roadies and bike store employees have been known to sneer at compacts. While some measure their manhood by the size of their big ring , smart cyclists choose equipment based on performance optimization, not vanity. People also like to emulate elite athletes. They want to ride the same frame as their favourite pro, so why not the same crankset? Here are some cases when a compact might not cut it:. Tyler Hamilton pioneered the use of compact cranks at the Tour de France with a solo breakaway stage win.

What is a compact crankset? Compact and standard. Can you spot the difference? Is compact right for you? What are the benefits of compact cranks? Here are 10 reasons to consider compact cranks: 1. Riders who once would have relied on the compact option are now finding that a mid-compact chainset and a wider-ratio cassette enables better performance.

Most companies are in agreement that compact is still relevant. For a wide spectrum of riders, mountainous environments and long-distance riding, it still makes sense. We only spec cyclocross, mid-compact or a 1x builds. The Frenchman expressed doubts that not every team is sticking to the same rules. The woman failed to stop at the scene of the incident, claiming she thought she had hit a fox. Cycling Weekly is part of Future plc, an international media group and leading digital publisher.