Children's mountain bikes often end up just being stunted "lesser" versions of their adult-sized counterparts, not necessarily weighing much less. Australia's CarbonXScycles, however, has taken a different approach with its Mad 6. The lightweight carbon fiber bike is designed from the ground up to fit li'l riders, to the point that it even features a custom dual suspension.

Company founder David Stevens was inspired to create the original Mad 1 after getting frustrated trying to find a decent-quality "off-the-rack" mountain bike for his 4 year-old daughter. The materials engineer ended up designing his own, using Solidworks 3D CAD software. Four years and several incarnations later, the further-refined Mad 6 is now being made to order.

Designed specifically for riders aged 4 to 7 years (weighing under 55 lb/25 kg), the bike features a carbon fiber/titanium frame, 20-inch custom carbon rims, a Shimano XT hydraulic rear disc brake, SRAM 1 x 9 gearing, plus a custom suspension fork and rear shock – the fork offers 65 mm of travel, with the shock managing 50 mm. According to Stevens, his purpose-built suspension offers better performance than a regular system that's simply been dialled way down.

As riders grow and get taller, the frame can be readjusted to one of three configurations, allowing a good fit to be maintained. The whole bike tips the scales at a claimed 15.4 lb (6.9 kg).

It's definitely worth keeping in mind, however, that the hand-built Mad 6 is designed for cross-country racing – not just for riding to school and the store. That fact is reflected in its pricing, which starts at a fairly adult-bike-sized US$2,775.

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