"Actually, Los Angeles is a very bike-friendly city," he persists. "I've done it, it's a great tour. It's not too hard. And it's really popular with Australians, they seem to like getting off the tour buses and doing something more active."

Ha. Me. Thirty-two miles. Quick calculation - that's 51.5 kilometres. Suddenly it sounds even more daunting. I'm in my sixth decade, and have never ridden more than 10 kilometres on a bicycle in one session. I give up on the exercise bike at the gym after five minutes.

OK, sign me up.

Eco-friendly tour company Bikes and Hikesrun cycling and walking tours of the city, with the 32-mile LA in a Day tour their top-seller. The tour goes from West Hollywood, via celebrity mansions in Beverly Hills and Bel Air, all the way to the beach suburbs of Santa Monica and Venice Beach, riding back along canals and bikeways  past some of LA's most iconic studios and shopping streets. Sounds like hard work, but also fun.

I rock up to the Bikes and Hikes office in West Hollywood, don helmet and water bottle, and start peddling with my guide, Ivan. We get to the street corner and discover my bike isn't changing gears properly. We go back, swap bikes. We peddle another kilometre or so ... my bike still isn't behaving. Perhaps it's me - I'm exhausted already.

But the friendly folk from Bikes and Hikes  don't let me give up that easily. They call for backup, and within minutes I have another bike. This one works perfectly, so its onwards and upwards, past one of Marilyn Monroe's homes, the house where Dustin Hoffman lives and Walt Disney's former estate, still staffed and maintained waiting for the day when Walt is cryogenically revived, in accordance with his will. Creepy.

We also pause outside a home still owned by Tom and Nicole (they didn't sell after their divorce) that rakes in $100,000 a month in rent. Surely not. "I mean, how do you know this information"?" I ask Ivan.

"We have very good sources - high profile people in the real estate business. It's true," Ivan insists.

Surprisingly, there are no issues with traffic at all - LA drivers are polite to cyclists, much better than in road-raging Sydney. And it's a beautiful blue-skied morning, without that layer of smog I associate with LA.

But the humidity on this hot summer day is unexpected.  It's really boiling, an absolute steam bath. Not typical dry LA heat - you can feel a storm a'brewing. I'm suffering terribly, with sweat pouring off me. My water bottle is almost empty, and we've been riding less than an hour.

"How far have we ridden?" I ask, struggling for breath as we pause at the gorgeous Greystone Mansion, a Tudor-style estate on a ridge in Beverly Hills, now owned by the city and often  used as a movie set.

"About four miles," Ivan replies. "This is the hardest part, once we get to the beaches it flattens out."

Great. Only another 28 miles to go. And how many more hills like this? Five. Mmm.

"Don't worry, we've had some clients who haven't made it this far. There is an option, you know..."

I look at Ivan hopefully. Seriously, I think I'm going to die.

"After this, we can ride up one more hill, to Michael Jackson's former house. Then, if you really feel you can't go on, we can turn it into a Legendary Homes tour and just explore Beverly Hills and Bel Air. It will be a  2½ hour tour rather than six hours."

Ah, flexibility. One of my favourite words. I love a good option.

Outside Michael Jackson's house, we chat to a woman selling Star Maps (this is one of the most popular stops on the Star Tours) before peeking through the gateway. Not quite the same without Michael - apparently he used to come out and say hi to his fans quite often.

I'm quite enjoying these intimate Hollywood titbits, so I decide to bail on the 30-miler, and turn this into a Homes tour instead. Pathetic I know, but at least I'll have had a fun day without killing myself.

And with that, the ride suddenly becomes easier. There's a light breeze, plenty of shady trees, and the roads are flat and peaceful. We ride past Tim Burton's house, full of bizarre sculptures including a Lurch-like giant hand holding a letter box; past the Witches' House, built by a Hollywood art director at Culver City in 1921 but moved to its present location in 1934; along Rodeo Drive, where we don't spot any Kardashians, and finally onto the famous Beverly Hills sign where we stop for an obligatory photo opportunity. Then before we know it, we're back at the Bikes and Hikes shop.

I'm totally spent, though I blame the heat, not my fitness. On a cooler day, I don't think I would have struggled as badly. Would I give the 32-miler another shot? Yes - but next time in winter.

The writer was a guest of Visit West Hollywood.

TRIP NOTES

MORE INFORMATION

visitwesthollywood.com.

GETTING THERE

United Airlines flies from Sydney and Melbourne to Los Angeles daily. See united.com.

STAYING THERE

Le Montrose is a stylish apartment-style hotel just off the Sunset Strip, with split-level suites containing separate living and sleeping spaces; rooms from $275. See lemontrose.com.

RIDING THERE

Bikes and Hikes' LA in a Day tour costs $162 a person, including lunch. The Movie Star Homes Bike Adventure costs $44. See bikeshikes.com.