There are dozens of cranksets to choose from. Here are the most important factors to consider.
Crankset type
You may see cranksets labeled for the intended drivetrain.
Type | Chainrings | BCD | Example |
|---|---|---|---|
Standard | 53/39 | 130mm | |
Compact | 50/34 | 110mm | |
Cyclocross | 46/36 | 110mm | |
Gravel | 48/32, 46/30 | ||
Track | 44 - 68 | 144mm | |
MTB | 42/32/22 |
Speed
Cranksets come in single, double, and triple speeds. You typically see single speeds on new mountain bikes, or single speed fixies. Doubles are very common, and used on racing, touring, and commuting bikes. Triples are used on older mountain and touring bikes. Riders are free to pick what they want, based on a tradeoff on gear range, weight, complexity.
Front derailleur compatibility
Derailleurs are designed for the size of the chainrings, so check if you have the right side.
Triple speeds need a specific derailleur with a longer rail to reach the low gear.
Crankarm length
Typical sizes are 170 - 175mm. Taller people need longer cranks.
Bolt pattern (BCD)
There's standard BCD sizes that let you mix and match, or brand specific attachments that limit your chainring options.
Bottom bracket type
Often BSA/English threaded (older, newer bikes), Pressfit (newish bikes), BB30 (cannondale, sram, fsa). There are others, but pay attention to what your frame has and what the cranks need to find a compatible bottom bracket.
Chainline
Road and mountain bikes have different chainlines. MTB is further outboard.
https://cyclechronicles.com/can-i-use-an-mtb-crankset-on-a-road-bike/
Q-Factor
Distance beetween pedals. This is the space between cranks, plus the distance from the angle of the crankarms.
Weight
Cranksets can be about 550g - 750g. Material, gears, design, and bottom bracket weight are all a consideration.
Frame compatibility
Make sure your chainrings and cassette teeth don't rub on the chain.