Kids drinking milkshake after bike ride


At Black Mountain sizing is simple – choose the bike that fits your child now. Because our bikes grow we always say that you should buy the model that fits your child today, not one that will fit them in 12 months time. Our EPOK growing technologies including UP:SCALE & IN:GEAR allow the bike’s size, geometry and gearing all to have a second life when you configure it into its larger mode. The bike gets longer, more responsive and faster as your child grows in size, confidence and ability.

We want to make the sizing process as simple as possible. Some people like to choose their bike by wheel size, others by inside leg measurement (which can vary hugely and is difficult to measure accurately) or age, but we prefer to keep it simple and use height. Try out our simple bike selector below.


1) Confidence Level:

Black Mountain monster size diagram

2) Height Measurement (cm)

  • 1 - Stand your child against a wall, without shoes.
  • 2 - Stand them upright, chin-up and place a book on their head.
  • 3 - Hold the book flat & level, touching the wall.
  • 4 - Mark the underside of the book where it meets the wall.
  • 5 - Measure from floor to the mark on the wall.
  • 6 - Do this 2-3 times to get an average measurement.
85 cm
125 cm
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