Condensed answer: No gear ratio can be labeled “best for skidding”. However, performing a skid is easier when the gearing is lower. That said, it’s irrational to choose a fixed gear ratio solely for skidding because overall performance and cadence are more important.
What is skidding on a fixed-gear bike?
A fixed-gear bike does not have a freehub. Consequently, the pedals never stop spinning when the bike is moving. This property gives the rider the option to slow down the bike by fighting the pedals.
If the rider completely locks the pedals, the rear wheel gets locked too, and slides across the ground. This is called skidding.
What are the factors facilitating skidding?
- Gear ratio
The term gear ratio describes the number of rotations that the rear cog and respectively the rear wheel make per 1 spin of the cranks/chainring.
For example, if the chainring has 46 teeth and the rear cog has 16, the gear ratio is 46:16 = 2.87. In other words, the rear wheel spins 2.87 times per 1 rotation of the cranks/chainring.
The higher the gear ratio, the higher the potential speed of the bike that can be achieved via pedaling because each spin of the cranks equals more rotations of the rear wheel and respectively a greater travel distance.
However, higher gear ratios make it much more difficult to climb and maintain a high cadence (rotations of the cranks per minute). High cadence is associated with more efficiency and better average speeds.
Higher gear ratios make skidding harder too because the rider has to overcome greater torque to lock the pedals. Consequently, if the main goal is to skid easier, going for more conservative gear ratios such as 46-48/16-18 will be helpful. Another benefit of a lower gear ratio is the faster acceleration.
Learning how to skid is more dependent on training the skill than focusing on gear ratios. After a while, a dedicated fixie rider will be able to skid without even thinking about the gears.
One of the most common issues is keeping too much body weight over the rear wheel. The more weight there’s on the rear wheel, the harder it is to lock it. For that reason, fixie riders often shift their center of gravity on the front wheel when learning how to skid.
Another option would be “hop skids”. In that case, the rider lifts the rear wheel slightly, locks the pedals while in the air, and then when the rear wheel returns to the ground it’s already locked and starts skidding.
Skidding requires specific leg strength and coordination that can only be developed through practice. The motion is unique and thus nothing else will prepare you for the experience. It’s also very important to learn how to keep your balance during skids.
Summary: What You Need To Know
- There isn’t a perfect fixed-gear ratio for skidding. But in general, if skidding is the main goal, it’s recommended to go for a lower (conservative) gear such as 46-48/16-18. Stay away from very large chainrings (over 50T) and small cogs.
- The most important part is to train the skill as much as possible and be patient. After a while, it will be possible to skid in virtually every gear.