Junior gearing can be a surprise to young athletes trying the sport of cycling for the first time. The young athlete attending his or her first USA Cycling-sanctioned event may be shocked to find his bicycle considered illegal. Parents may also wonder why this is so, especially when they have paid a lot of money for a bicycle they were told was race-ready. The main purpose of junior gear restrictions is to help the young rider develop a good pedal cadence and to avoid injury. Junior gear restrictions also level the playing field for developing juniors who may be at a disadvantage against rivals who possess physical advantages such as height and power.
The test to see if a race bike is legal or not is called the "rollout method" or simply "junior rollout", which is the distance a bike travels backward in a straight line through one full pedal revolution when the bicycle is in its largest gear.
To calculate how far a bike will travel relative to its gears, USA Cycling determines gear ratios with respect to race age and discipline and applies in all events in that discipline. There is no restriction for road, cyclo-cross or mountain bike races. For track the limits are*:
- Ages 17-18: Unrestricted
- Ages 15-16: 6.93 meters (22'9")(50x15) **
- Ages 13-14: 6.45 meters (21'2")(50x16)
- Ages 10-12: 6.05 meters (19’8”)(52x17)
* Note that the gear ratios listed are merely suggestions. The distance rolled out is the governing standard.
** For 15 & 16-year-old juniors who are competing in keirin or Madison championship events, the 17-18 (unrestricted) gear limit applies.
Race officials will usually provide a courtesy gear check prior to the start of a junior race, but it is the gear check immediately after the junior race that determines whether a junior's bicycle is legal or not.
It is also important to note that not all cycling tires have the same diameter, which can give a bicycle a rollout distance different than the distance provided by the gear recommendation.
Junior riders need to roll out their bicycles on their own prior to attending a USA Cycling-sanctioned event to determine whether they will be compliant with the rules.
