You have ridden a bike before, haven't you?" asks the young assistant at the bike rental place as he watches me trying to pedal away.
Cheeky monkey. "Of course I have," I retort, desperately trying not to fall off. "I was riding bikes before you were born."
What I don't tell him is it's about that long since I was last on one. Cycling has been my least preferred method of transport since I was knocked off my bike by a car when I was 11. I've only cycled a couple of times in the past 30-odd years.
So it's no wonder I'm wobbling madly as I try out the bike in the Blazing Saddles premises near San Francisco's Hyde Street Pier. I eye my 6-year-old's tag-along bike attached to the back of my husband's cycle in envy.
It's an easy ride from here to the Golden Gate Bridge, the assistant tells us, only 70 minutes, and then 20 minutes to cycle across the bridge itself. There's a separate lane for pedestrians and cyclists, he assures me, so I'm not going to have to chance my luck with speeding traffic.
Most people who bike the bridge keep going once they reach the northern end and cycle for another 10 minutes to the pretty seaside town of Sausalito. Then they catch a ferry back to the city and return to the bike garage via Fisherman's Wharf. But we don't have time - we've got a flight to London later today - so we'll have to ride straight back.
We wheel our bikes down the hill to the water's edge, then we're off. At first it's easy - like riding a bike, ha ha - but after a few minutes we hit a hill and I have to get off and push. By the time I'm back in the saddle and riding down the other side of the hill through a park that is part of Fort Mason, a former Army base, my husband and daughter are already disappearing into the distance.
It's a bit depressing, but suddenly I see beyond them the Golden Gate Bridge stretched out over the water. Yesterday it was almost completely obscured by fog, but the sight of it today inspires me to keep going.
Now we are in an area known as Marina. The Pacific Ocean is pounding against the sea wall on my right and to my left is the stunning classical-style Palace of Fine Arts and then Marina Boulevard, lined with elegant Spanish-style homes, some of the most expensive and picturesque real estate in San Francisco.
A few minutes later we're on to the Golden Gate Promenade, which cuts through the Presidio, once a military base and now a famous park. The promenade takes us through Crissy Field, a former airfield that's now a scenic natural area, its marshes and sand dunes so unspoiled it's hard to believe we're just a couple of kilometres from the hustle and bustle of the city.
At the end of the promenade is a busy recreational area, a bookstore and the Warming Hut café. The thought of sitting inside nursing a mug of hot chocolate is tempting but I'm not stopping now. A bit more effort, including a brief walk up Long Ave, and we're on the bridge itself.
There's no chance to savour the moment because I have to navigate my way through the dozens of dawdling pedestrians. When I try to warn them I'm coming through I discover my bicycle bell doesn't work. Calling out "Excuse me" is ineffective so in desperation I resort to yelling "Ding, ding". Amazingly it does the trick.
Gradually the crowd thins until I'm able to pick up speed. Six lanes of traffic zoom past to the left but I feel safe thanks to the barrier between us. The handrail on my right isn't particularly high and it is rather windy but any initial nervousness vanishes as it sinks in that I am cycling on one of the world's most recognisable landmarks. Apart from having to carefully manoeuvre around the bases of the two towers, riding across the bridge is the easiest part of the whole journey, as well as the most exhilarating.
I finally catch up with my husband and daughter, who have pulled over alongside the railings. The view is breathtaking. We watch the ferries going across San Francisco Bay and taking tourists to Alcatraz.
In the distance is the outline of the city and we can make out distinctive buildings like the triangular Transamerica Pyramid skyscraper, and the cylindrical Coit Tower, shaped like the nozzle of a fire hose in tribute to San Francisco's fallen firemen.
We linger as long as we can then ride almost to the northern end before reluctantly turning back. With the wind behind us the return journey is a piece of cake. By the time I'm whizzing down the hill past Fort Mason I can only just resist yelling out "Woo hoo!". This is fun.
We get back to Blazing Saddles three hours after leaving and the assistant who doubted my cycling ability smiles as I hand back my bike. "Glad to see you made it," he says. Me too.
Getting there: Air New Zealand flies directly to San Francisco every day.
Where to stay: We stayed at the Sir Francis Drake Hotel near Union Square. Check out the doormen dressed as English Beefeaters.
Getting around: You've got to go on a cable car at least once for the experience but travelling by taxi is quicker, easier and can be cheaper if there are more than two of you.
Cycling the bridge: Stay right. Cyclists give way to pedestrians. In the US, the rear brakes are on the right handle bar and the front brakes are on the left. Rentals range from US$7 an hour for a basic bike to US$11 for a tandem. See blazingsaddles.com.