Cycling is both a hugely popular and immensely enjoyable sporting activity in today’s modern world. It has numerous advantages over other forms of travel, as it is fun, provides great exercise and is environmentally friendly. The bicycle is a complex machine, with many confusing components required for it to be fully functional. The bike’s owner can replace these components in the event that the existing part is not working, or not performing to the standard required. One of these components is the crank set.
It is the intention of this guide to provide the reader with detailed and comprehensive information about crank sets, so that they can make their own, well-informed choice when it comes to buying them. In addition, this guide will look extensively at the reasons why eBay, the popular auctioning website, is such a great place to shop for crank sets online.
What Is a Crank Set?
This section of the guide will very closely examine the crank set; what it is, what it does and how it does it.
A crank set is, in short, the part of the bike that translates the cyclist’s energy input (via the feet) into the actual motion of the bike itself. This makes it an absolutely indispensable component. Its appearance is that of a circle with jagged, serrated edges, attached to who separate lengths of metal (or whatever material the crank set happens to be made from).
There are two main components to a basic crank set (though these can take many different shapes). This section of the guide will explain each of these in turn. They are:
- Chain Rings: the chain rings, sometimes called spindles, are circular in shape, usually consisting of an outer ring supported by connecting beams. The outer ring has small ‘teeth’ (small projecting spikes) placed around it at narrow, regular intervals. Chain rings come in many different sizes, measured by number of teeth and width. Some crank sets will feature up to three chain rings, each of different size, allowing the cyclist to change ring, and thus change the ratio of input to output, allowing different surfaces and gradients to be navigated.
- Cranks: the cranks are two ‘arms’ of sorts. They attach to the chain rings in the centre, one on either side, and in a fixed position. These arms are then attached to the pedals at the other end. This means that turning the pedals turns the chain rings, which is an essential part of the process that causes the bicycle to move.
How Does It Work?
The crank set works with the rest of the bike in three main places. These are:
- The Axle: the chain rings are connected to the axle. This means they can turn freely, whilst still being firmly attached to the bike.
- The Chain: the chain wraps around the chain ring. The teeth hook onto the individual chain links, and pull them around using the kinetic energy acquired from the cranks. The chain then carries the kinetic energy back to the rear wheel, which turns it, propelling the bike.
- The Pedals: the cranks each hold a pedal. The cyclist uses their feet to move the pedals, which turns the cranks, which turn the chain ring, and so on.
Many crank sets feature multiple chain rings of different sizes, which can be switched between. The size of the chain ring affects the amount of kinetic energy transferred from the pedalling motion to the rear wheel; larger rings mean the chain travels further with each turn, which is more efficient on flat surfaces, and generates more energy and thus more speed.
However, this also means that on steeper gradients, it becomes significantly harder to turn the pedals. This is the purpose of the smaller rings; they require less energy to turn, so are switched to when the gradient requires more energy of the cyclist, to balance the energy input to motion output ratio.
Features to Consider When Buying Crank Sets
This section of the guide will cover in great depth all the various factors and considerations that it are advisable to thoroughly think through before buying a crank set. These factors are:
- Rotor size
- Number of speeds
Crank sets are available in numerous different colours. This is a matter of personal taste, but one that affects the entire visual sense of the bike. It is a good idea to take into account the colour scheme prevalent in the rest of the bike, to give an idea of which colour would be best suited.
Crank sets, like any other part of a bike, can be made from a number of different materials. The following is a lost of the most commonly used materials, along with brief descriptions of their characteristics:
- Aluminium: Aluminium is a light, strong and relatively cheap metal, making it the most popular in use in today’s cycling industry.
- Carbon Fibre: Carbon fibre is ultra lightweight, ultra durable and ultra strong, making it the ‘elite’ choice of material. It is also expensive and brittle, making the overall cost of using carbon fibre very high.
- Steel: Steel is heavy and tough, a classic staple of bicycle manufacture, and generally the cheapest option.
- Titanium: Titanium is only a little heavier than aluminium, but is much stronger, and will never rust. It is the highest quality metal from which crank sets can be made.
- Alloy: an alloy is essentially a kind of mix of two or more different elements. This often allows the different strengths of those elements to be combined, whilst removing the weaknesses. Alloys are a well-balanced option in terms of functionality, lifespan and price.
The ‘rotor size’ is measured by the diameter of the chain ring in millimetres. Common sizes are 140, 160, 170, 180 and 185mm.
Chain Ring (or Spindle) Interface
The chain ring (or spindle as it is sometimes called) is connected to the axle via an interface. There are a huge number of different kinds of spindle interface. It is very important to check which kind is required on the bike in question before buying.
Number of Speeds
The number of speeds at which a bike can travel is affected directly by the crank set; namely by the number and size of the chain rings. Crank sets are designed for bikes with specific numbers of speeds in mind. Check how many speeds your bike has (a number between 1 and 11 usually) before buying a crank set, and ensure that the crank set will fit a bike of that type.
Other factors include:
- Number of teeth
- Crank arm length
- Number of chain rings
Usually, looking at the bike’s current crank set will give a good indication of the kinds of specifications required in any given case.
There are many different types of bike, and so naturally there are as many different types of crank set to fit them. The following is a list of some of the main variable features:
- Tandem: for bikes with more than one rider
- Chain Guard: a plastic shield to prevent environmental damage.
- Chain Guides: a plastic housing designed to keep the chain on the chain ring on rough terrain.
- Freewheeling: allows the cyclist to change gears whilst coasting.
- Left-Side Drive: a completely inverted crank set.
- Compact: a smaller variation.
- Bent Crank Arms: a mostly visual choice, as they provide no discernable advantage.
How to Buy Crank Sets on eBay
The popular auctioning website eBay is a great place to shop online for crank sets. It features a huge selection of products, as well as an intuitive, simply designed interface, which allows exceptional ease of access.
To find the relevant area of the website, start from the eBay homepage. There is a list of links to categories found towards the left side of the screen, from which the Sports & Leisure option should be chosen. This opens up a new list. Repeat the process, following the links to Sporting Goods, Cycling, Bike Components & Parts, and finally Chainsets & Cranks. The search bar provides a quick and easy alternative to link navigation; simply type in ‘crank sets’ and press search to achieve similar results.
The page should now display a list of items. This list can be customised using various filtering options, found in the page’s left margin, which include colour, material, spindle interface, rotor size, number of teeth, price, condition and seller’s location amongst many others.
Items are represented in the listings by a thumbnail image, along with the item’s name and a brief description. Clicking on an item’s entry in the listings will relocate the user to that item’s individual page, wherein more detailed product information and specifications can be found, in addition to seller’s information (such as ratings, user feedback and contact information).
This combination of the diverse array of items to choose from and the user-oriented, consumer friendly design make eBay the perfect place on the internet to shop for crank sets.
Cycling is an exceptional activity, providing an unparalleled balance of sporting enjoyment and practical transportation. It is important to have fully operational parts if a bicycle is to work properly, and crank sets are one of those vital components. This guide set out to provide information about crank sets. Numerous features of crank sets were discussed, including:
- Chain ring size
- Number of speeds
This guide concludes that eBay, the online auctioning platform, is a superb means of shopping for crank sets, thanks to its simple design and diverse pool of products.