It all started with my son's 10th birthday. He got a new bike. He's tall and his last bike had him riding toddler-style with his knees at right angles. That particular model was found in a skip looking forlorn with a missing wheel and dangling chain.

It took a bit of persuading to convince my son of the need for the new bike - in our house this is a vehicle for transport rather than just a toy.

He wanted to stick to the old one "cos of the cool handlebars", but was won over when we pointed out that cycling with knees touching ears is actually not so swish. So, after a trip to the bike workshop in Magdalen Road, it was voila! A new bike. Brand new - something that, given the money, most people would think twice about.

When you get a bicycle for your child you might think he's grown taller again (I knew I should have stopped feeding him!). But he's probably just between frame sizes.

At his current growth rate he would outgrow the smaller frame in about eight to 12 months. So going for the larger frame seemed to make sense (although it was a pity they didn't have it in red).

But even with the lowest saddle setting he was just slightly too small and a tad wobbly.

Reg Taylor's cycle shop in Iffley Road has a few good children's bikes - and helpful staff who pointed out that this size would be good for a few years and with a reliable make, worth the investment.

I can't understand why anyone would throw a good bike in a skip. Are they really so cheap you can use them like disposable contact lenses? Throwing bikes away or leaving them attached to railings when you find some idiot has kicked in your wheel doesn't make sense. Better to carry it to a repair shop and make sure you have insurance in case it happens again.

Even if it's too expensive to fix, the Oxford bike workshop can take old parts and, Frankenstein-like, use them to create new bikes. Alternatively, I have one friend whose husband made their back garden into their own workshop, swapping parts from three bikes with the aim of making the ultimate mean machine (well, racer actually).

They're still waiting for the birth of that model, after which they'll finally be able to mow the lawn again. Being from a fairly large family, I used to receive plenty of hand-me-downs. Bikes were no exception. But recently I've noticed there are fewer bicycles being handed down through cousins or other family members.

One reason for this is that children's bikes are often poorly made or designed. They're just not lasting long enough to be passed down. Or perhaps five- to seven-year-olds have some exciting stunts that I don't know about that totally trash the bikes.

Maybe manufacturers should concentrate more on making kids' bikes more resilient, and focus less on Barbie/Spiderman/go-faster stripe designs. Now I just need to find a home for the cast-off. Small kid's bike with cool handlebars, going cheap - anyone?