WIRED: Black Mountain Pinto and Skøg

We've charted some impressive innovation in the two-wheeled world of transportation, the latest electric folding bikes, most technologically advanced triathlon bike ever and McLaren's F1-inspired offering - but the latest kit from Black Mountain takes the crown of our favourite bike you can buy right now.

Children's bikes account for some 30 per cent of the UK bicycle market, which is currently dominated by the likes of Hoy, Frog and Islabikes. Indeed, business is going so well for Islabikes, based in Shropshire, that is has also established a US base in Portland, Oregon - a feat even more impressive when one considers that none of its models are available on the high street - you have to order online direct from the company. Check eBay and you will find that second-hand Frogs and Islabikes are snapped up feverishly for very little markdown on the RRP, no doubt down to doting parents unwilling to scrimp (too much) on their precious offspring's new mode of transport.

However, even though these learner bikes are increasingly popular, the problem - as any doting parent will solemnly tell you - is that small children have an annoying habit of rapidly growing larger as the months and years pass. Thus, as soon as you hand over hundreds of pounds on your nipper's very first bike, within all-too-few perambulations around the local park it's already too small and so the adults are forced to fork out for a bigger size.

This is exactly the problem that the clever folk at Black Mountain have solved. Based in Raglan, Monmouthshire, the company has designed two new infant bikes that through a series of adjustments and add-ons grow as your child grows.

The brand’s first two models, the PINTO (for children of 3–5 years) and SKØG (5–8 years) can both be set up in three modes: either Balance, Small Pedal or Large Pedal. This effectively means you get three bikes in one. Black Mountain claims the PINTO replaces both a traditional 12in and a 14in bike, while the SKØG takes the place of 14in and 16in bikes.

How do they work? Black Mountain founder Andy Lloyd, who has a background in motorsport engineering, realised that the traditional diamond frame bike design was in fact a weakness when it came to designing bicycles for children as it did not address this main problem that children grow. After eight years of development, he created Black Mountain's patented EPOK system, which dispenses with the diamond frame and allows the rear triangle to be moved forward to create a longer top tube.

The gearing system is also supposedly the world's first that can be moved up as the bike grows. A "PowerPack" includes cranks, pedals and a lightweight, oil-free drive belt (six times lighter than a chain), transforming the balance aluminium bike into a pedal bike. By adjusting the frame and gearing system, it increases the frame size and gearing by 20 percent, which will typically result in the bike lasting 12 to 24 months longer than a fixed-frame bike.

There is even a custom saddle and inverted seat clamp so the saddle to go extra low for very small children.

Black Mountain isn't the first to make an expanding kids' bike. In 2016, LittleBig brought out the 3-in-1, which flipped the rear part of the frame to make a larger balance bike, then you had to bolt on a chainring and cranks. Black Mountain's offering, however, with its belt drive, adjustable gearing and "growing triangle" frame takes this concept much further.

Both £330 bikes come in orange, neon green, sky blue or purple.