Give your kids’ MTB an adult granny gear with MicroSHIFT

Kids’s bikes have smaller wheels and less terrain clearance. That makes the rear derailleur more vulnerable. (Photo: MicroSHIFT)
Kids’s bikes have smaller wheels and less terrain clearance. That makes the rear derailleur more vulnerable. (Photo: MicroSHIFT)
  • 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.

kids mountain bike
Junior mountain bikers on 20” wheels, love trail riding. And deserve the gears, to get them up steep terrain.. (Photo: MicroSHIFT)

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.

MTB gearing
The MicroSHIFT super short derailleur cage remains clear of terrain, even at full extension. (Photo: MicroSHIFT)

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.

mountain bike gears
MicroSHIFT's new super short system. With its very compact derailleur cage. (Photo: MicroSHIFT)

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.


We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.