Cyclo-therapy: The road up to Ditchling Beacon has roughly the same gradient as Mont Ventoux – but it's 14 times shorter

Every year more than 27,000 people cycle from Clapham Common in south London to the seafront at Brighton in the biggest charity event of its kind. And that's why I've always avoided it. Firstly, because 27,000 people is a ridiculous number of riders to send along narrow Sussex lanes, but also because it's for charity.

I'll explain. I dug deep for a friend who recently pedalled from London to Paris for the hospice that cared for his late mum. But I've always thought the industry that has built up around endless charity challenges threatens to cheapen the efforts of heroes like him. Recently I was asked to sponsor a man I've never met who planned to "row" across the Channel – in a gym.

But I steered close to hypocrisy earlier this month when I joined an 'Independent' team riding from London to Brighton for ActionAid. At least there would be no bottlenecks – about 20 of us met outside Buckingham Palace in specially made jerseys. We processed south towards the start of the ride proper in Clapham but, being antisocial as well as occasionally uncharitable, I then upped the pace with two other regular cyclists. We wouldn't see the rest of the team again.

The 54-mile route isn't the prettiest in England but it has its moments. The biggest landmark comes about 10 miles from the beach when the South Downs rear up like a great green cliff. The road up to Ditchling Beacon has roughly the same gradient as Mont Ventoux, which I climbed in July, but it's 14 times shorter. Yet for reasons I can't explain, the mile-long ascent always has me straining.

The reward is stunning views and the long descent to Brighton where, after three hours in the saddle, I dipped a wheel in the Channel. It would take the rest of the team twice as long but on bikes (and legs) in various states of repair, theirs was easily the greater achievement. And they've broken my cynicism. It's all too easy for cyclists like me, for whom the London to Brighton barely constitutes a training ride, to forget that challenges come in all shapes and sizes. And if there's money to be raised, who are we to pooh-pooh these endeavours? Still, don't ask me to sponsor anything that involves toiling in the comfort of an air-conditioned gym.

s.usborne@independent.co.uk or see independent.co.uk/cyclotherapy