Road vs Track Gearing: What's Different for Junior Racing?
If your child races both road and track, you'll quickly discover that the gearing rules, the parts, and the whole setup philosophy are different between the two disciplines. Here's what you need to know.
Different Rules, Different Limits
Both road and track racing have rollout restrictions for young riders, but the way they're applied differs. Road racing uses the standard British Cycling rollout limits based on age category. Track events often specify restrictions in gear inches rather than metres, and the limits can vary by event and velodrome.
The key difference: on the road, your rider has multiple gears and the commissaire checks the highest possible combination (biggest chainring, smallest sprocket). On the track, most junior events are fixed gear with a single ratio — so the one gear you choose is your rollout.
Track: Fixed Gear, Single Ratio
Track bikes run a single chainring and a single fixed sprocket. There's no cassette, no derailleur, no shifting. This makes compliance simpler in one sense — you only need one combination to check — but it also means you need to choose that one ratio carefully.
Common track setups for juniors:
- Under-14/16: Typically 46-48T chainring with a 15-16T sprocket
- Junior (under-18): 49-51T chainring with a 14-15T sprocket
Track sprockets are sold individually and are easy to swap — just unbolt and replace. This is much simpler than dealing with cassettes on a road bike.
Road: Multiple Gears, Highest Matters
On the road, your rider has a full drivetrain with multiple gears. The rollout check is based on the highest possible gear — the biggest chainring paired with the smallest sprocket on the cassette. Every other gear combination is irrelevant to compliance.
This means you need to think about:
- The big chainring size (the small ring doesn't matter for compliance)
- The smallest cog on the cassette
- Your tyre width (affects wheel circumference)
Parts Availability
Track parts are generally easier to source for compliance because individual sprockets and chainrings are standard track components. Road parts are harder because you're fighting against groupset ecosystems designed for adult racing.
Track advantages
- Individual sprockets available in any tooth count (14T-20T common)
- Track chainrings available from most track component brands
- No cassette/derailleur compatibility issues
- Swapping ratios takes minutes with basic tools
Using the Calculators
The track calculator lets you enter a target rollout in inches and finds the chainring/sprocket combinations that match. The advanced calculator shows every road combination and flags which are legal for each category.
If your child does both disciplines, it's worth checking both calculators before buying parts — sometimes a chainring that works for road can double up for track with the right sprocket.
The Practical Reality
Most families who race both disciplines end up with separate bikes — a road bike with gears and a track bike with a fixed setup. The gearing rules are different enough that trying to make one bike work for both is usually more trouble than it's worth.
If budget is tight, focus on getting the road bike compliant first (since road racing is more common for youth riders), and borrow or hire a track bike for velodrome sessions. Many clubs and velodromes have hire fleets with compliant gearing already fitted.