12" Bikes
Browse used 12" bikes for sale from riders across the UK. A 12" bike is the usual first pedal bike, sized for children of about three to four and a half years with an inside leg of roughly 36cm to 44cm. Most run a single gear, short-reach brake levers and cranks around 89mm long so small legs can turn a full circle.
What makes a good 12" first pedal bike?
Weight and brake reach decide whether a child can ride it. Aim for something under about 6kg, with levers that adjust close enough to the bar for small hands. Bikes such as the Frog 40 and Islabikes Cnoc 14 family are built around child-specific cranks and narrow bottom brackets, which matters more than the frame material. Removable stabiliser mounts are useful but most children who came off a balance bike will not need them.
Should I get a 12" bike or a balance bike?
If the child cannot yet balance without putting a foot down, a balance bike teaches that faster and with fewer falls. If they can already glide, skip straight to pedals. Some 12" bikes come with the cranks removable so the same frame does both jobs. The next step up is a 14" bike, usually around age four or five.
What should I check on a used 12" bike?
Look at the chain and chainring for rust, as these bikes spend winters in a shed and a seized chain is common. Check the freewheel engages without slipping when you turn the cranks forward and pedal back. Pull the brake levers and confirm the pads still meet the rim squarely rather than sitting half off it, since children's bikes are often left out of adjustment for years. Rock the wheels side to side to feel hub bearing play, and check the tyres for perished cracking at the sidewall, which is more common than tread wear at this size.
How much should I pay for a used 12" bike?
Supermarket bikes sell for very little used and are rarely worth collecting, given their weight and steel components. A well-kept Frog, Islabikes or Hoy commonly goes for around half to two-thirds of new, and holds that value again when you resell. Buying new makes sense only if you want a warranty or nothing suitable is listed nearby; otherwise the used market at this size is deep, and kids' complete bikes turn over quickly as children grow out of them.