- Unless you are a fixie riding urban commuter, gears matter. A lot. Especially on mountain bikes.
- Cassette range been steadily increasing during the last decade, as single blade systems have replaced the dual-chainring drivetrain.
- But what about kids? If your junior rider wants a lot more gearing range to test their endurance on those steep climbs, there’s a compact new derailleur to make that happen.
Many adult mountain biking technologies work a treat on kids' bikes. Disc brakes. Suspension forks. And trick compound tyres.
Industrial designers shrink adult components and make some ergonomic adjustments, shaped for use with little hands and bodies. This brings many proven adult mountain bike technology benefits, to junior riders.
But there are things that are not easy to get right, on smaller bikes - for smaller people. Drivetrain technology and gearing are challenging to transfer from the adult mountain bike catalogue to a kids' bike.
Nearly all new adult mountain bikes roll 29” wheels, while kids' bikes are equipped with 20” wheels and tyres. And that creates complication and compromise, regarding gears and component clearances.
Bigger gears need longer mechanical parts
Contemporary derailleur cages are long, accounting for the significant growth in cassette range.
When I started mountain biking a decade ago, the average rear cassette had a 36t granny gear. That has grown to 52t. To tension a chain over an extended range, you need a longer derailleur cage.
If you fit a modern derailleur cage to a kids' bike, it will risk dragging on terrain because those 20” wheels position the bike closer to the ground.
A small mech - for small riders
The solution for better kids's bike gearing? An Advent super short drivetrain system from MicroSHIFT.
In business since 1999, MicroSHIFT specializes in clever drivetrain solutions, and its super short derailleur cages work perfectly on 20” wheeled mountain bikes.
Designers at MicroSHIFT have created the Advent drivetrain to give kids the same gradient ascending ability as their parents. The MicroSHIFT rear derailleur works with an 11-38t cassette, giving a 20” wheel bike similar granny gear climbing ability to an adult mountain bike with a 52t lowest gear.
Easy to use - and work on
The 9-speed Advent design makes it easy for parents to adjust gearing and kids to trigger those shifts. Microshift's team shaped its Avent shifters to have a 43% shorter throw than most rivals – making it much easier for tiny fingers to shift gear confidently.
Adjusting drivetrain tension might appear simple, but many a parent has been humbled when attempting to master those tiny limit screws.
The MicroSHIFT Advent drivetrain features 20% less clutch force than an adult mountain bike’s gearing system. That makes it easier to set and perfect the shift quality on a kids’ bike.
