Bradley Wiggins has a lot to answer for. Not only has he single handedly shown the world that a man with facial hair can win cycling races, but he has also helped inspire a generation of fluorescent Lycra wearing cyclists – the likes of which now fill our roads.

In 2012 – the year of his Tour de France fame – Bradley Wiggins stirred controversy when he publicly backed a law that would make bicycle helmets compulsory for all cyclists.

At the time, a London cyclist had just been killed in a bus collision. But even that wasn’t enough to stop the wheels coming off Sir Bradley’ well intentioned campaign. Most people think, like Bradley, that wearing a bicycle helmet is a no-brainer, but the truth is rather more twisty-turvy.

Several times have I been in the presence of a fist-waving car driver, uttering profanities at a cyclist for not wearing a helmet. To them, cycling with a naked head looks as bad as a child not wearing a seatbelt or a driver texting while on the motorway. And on the face of it, protecting one’s noggin with a hardened polystyrene shell is common sense. But believe it or not, lots of people actually think it’s safer without a helmet.

Imagine yourself behind the wheel for a moment. There is a cyclist ahead of you. When you overtake, how close to you drive? The chances are that you will give the cyclist more room if (a) they aren’t wearing a helmet or (b) they are a woman.

It almost certainly isn’t deliberate, but one Bristol researcher discovered that drivers are more dangerous around cyclists when they wear a helmet. He cycled around the city with and without a helmet, and in different regalia, measuring how close cars came to him. He recorded that cars drove closer when he wore a helmet. Amusingly, he also discovered that when he put on a wig, so as to look like a woman, drivers also gave him a wider berth! (Make of that what you will!) Serious accidents may be more common with cyclists who wear helmets. But it may not just be drivers who are at fault. Some experts argue that the cyclists themselves might also make more risky swerves when they have a helmet – in the mistaken belief that their helmet gives them greater protection than it really does.

The stats don’t look good for Wiggins’ belief either. Countries that introduced cycle helmet laws have so far seen no significant reduction in cyclist injury and death rates. And the CTC, the UKs largest cyclists’ organisation, are also against helmet-wearing campaigns – claiming they discourage people from ever getting on two wheels and taking some much needed exercise. But all that said, I still choose to wear a helmet when on my bike. For even though a helmet may only protect the top of your head, I prefer the security of having one. Most medical organisations think they are sensible – the NHS, World Health Organisation and the Cyclists Highway Code all advise that cyclists should wear a helmet – especially children.

I suspect that as helmet technology improves and roads become more cycle-friendly, the benefits of wearing a helmet will become clearer. Until then, whether a cyclist wears a helmet is a matter of personal preference. The jury is still undecided.

Which, strangely enough, is how most of us feel about Bradley’s beard.