(last updated: 8/30/99)
LinkExchange Member
BMX Bicycle Racing Gear Charts
Basically, if you are getting bad starts AND aren't spinning the gear out 3/4 way down the first straight, then the gearing is too hard. Try going one tooth lower in front, unless your gearing is waaay hard then you could try either going up 1 tooth in back or down 2 to 3 teeth in front. changing 1 tooth in back is about the same as changing 2-1/2 teeth in front. If it seems that your starts are great, but you spin out by the first jump, then you need to go up a tooth in front. Basically gauge how you feel on the current gearing now, and use the charts as just a reference point for adjusting either way.
Also, it depends how long the track is. You can fine tune the gearing after you get the first straight gearing settled. The first straight makes the race.
I run about a 54 to 57 inch gear on my cruiser (17 in back and 40 in front, usually), with 180mm cranks, depending on the track but I run 17/40 most everywhere. On a 20" bike, I run a 45/16 gear setup which is similar to my 24"er.
A little BMXer (like a 7-year old) may try several gear-inches lower, but check around the other kids' bikes and get an average. Remember to consider what crank length they are running with those gearings, too. Longer cranks get better starts and power and turn slightly harder gearings, BUT it's harder to spin for a long time. Shorter cranks are easy to spin (smaller circles), BUT starts need lower gears and shorter legs.
Good luck, Pickle
These GIFs of gear charts are only about 16kb each in size.
Click here for chart of 20" SEWUP wheels.
Click here for chart of 20" x 1-1/8" wheels.
Click here for chart of 20" x 1-3/8" wheels.
Click here for chart of 20" x 1.5" wheels.
Click here for chart of 20" x 1.75" wheels.
Click here for chart of 24" x 1-1/8" cruiser wheels.
Click here for chart of 24" x 1-3/8" cruiser wheels.
Click here for chart of 24" x 1.5" cruiser wheels.
Click here for chart of 24" x 1.75" cruiser wheels.
