I'm the first to admit it's one of the (less-important) reasons for riding a bike. 

I suspect that, for women, it's slightly lower on the list than for men.  Or should I say boys?

But that thought stays, mostly dormant, in the back of each rider's mind.  Why else do middle-aged people suddenly develop a penchant for Harley Davidson paraphernalia?

I've got to hand it to the Harley marketing gurus - the sales of Harley Davidson accessories are a global phenomenon.  Everyone knows of Harley, and most of them know nothing about the great American ride.

But back to the sex appeal thing.

I've rarely seen it more obvious than at last weekend's Big on Bikes Expo in Fremantle.  

In terms of range, Big on Bikes is not a big show.  In terms of testosterone secreted (by men and women), it's a bloody screamer.    There wasn't a single person who did not stop to look closely at a motorcycle.  And every single one of them will deny they were thinking about its effect on their sexual attractiveness.

But, let's face it, bikes are sexy, and by implication so are the people who ride them.   The sexier the bike, and the harder you ride it, the sexier you are.  I'm sure that's how it works. 

There were lots of glazed eyes at the MV Agusta stand, which was done out in the colour of universal sex appeal - red.  And while the Vespas are definitely cute, and fuel efficient and quirky, the appeal is not the same.

There were far more pairs of jeans furtively adjusted while walking away from the pure sports machines, than from the cruisers.  But does it work?  Hard to tell.   

My personal theory is that it works on the rider, but unless your audience is jail-bait naïve, it doesn't work on the watcher.   

Of course, depending on your point of view, you can always score a date with Mrs Palmer or Mr Buzzy.