Today’s coaches corner is all about gears. Simon Tacx wanted to understand more about the variations in chain rings & gear ratios.
Firstly basic terminology: Spider: this is the five probes which spread out from the centre of the cranks. Road bikes traditionally have five to spread the load where mountain bikes typically have four due to the smaller circumferences.
Crank length: this is the length of the pedal arm from the centre to the pedal. These came range from 160mm to 175mm. Depending on the length of your length the length of your cranks will vary.
Chain rings: these are the discs which go around the pedals which generates the momentum to cycle. See below for further information. Bigger = harder small = easier
Cranks sizes: 130 or 110. This is the circumference size of the cranks rings. 130 is standard & 110 compact. If you buy 110 chain rings they will not go onto a 130 crankset and visa versa.
Rear cassette: either 10 or 11 cogs on the rear wheel. Smaller = harder, bigger = easier. The opposite to the front chain rings.
There are three traditional chainring set ups for the front of your bike. Triple, compact & standard. Each have their merits and according to your personal preferences. With the outer ring and then either one or two smaller inner rings. The size is expressed in teeth, being the number of teeth on each ring, e.g. 53/39 means 53 teeth on the outer and 39 on the smaller inner.
Triples: this is where you have three chain rings at the front going 50/34/28 teeth on the chain rings. Great for climbing nasty hills / mountains are you have a greater ranger of lower gears in order to turn the pedals over.
Compact: typical 50/34 teeth. Once more good for climbing to if power to turn the pedals over is hard. Ideal for new cyclists developing their fitness levels.
Standard: 52/39 or 53/39. Larger the outer the harder to turn over so once you have gained sufficient strength in the legs you can look to have the more traditional chain rings on the front.
Rear cassette ratios: you can change the cassette at the back with simple tools. With this you can change the ratios to make the ride easier if require. 11-23 is best for flat fast courses as you won’t require a higher number for climbing. 13-28 is great great for climbing as you have a 28 tooth rear cassette to help make climbing easier.
In correlation with your chain rings you can adapt your set up to meet your cycling needs.