Perched on the edge of a narrow, gravel road with a helmet strapped on my head I start to think I have made a horrible mistake. To my left, a sheer 1000-metre drop into the valley below. In front a slip has wiped out much of the already narrow pathway.
"Is it to late to change my mind?" I ask the tour guide.
"Yip." The short, confident reply seals my fate.
And so we're off - a group of gringos (foreigners) on mountain bikes adorned in fluorescent orange safety vests racing their way down the World's Most Dangerous Road.
The name was given to the 60-70km route between Bolivian capital La Paz and popular weekend getaway Coroico by the Inter-American Development Bank in 1995. It is affectionately known by locals as El Camino de la Muerte (The Death Road).
A new road connecting La Paz and Coroico was completed in 2006. Most traffic now uses that one, leaving the old route to the hundreds of tourists who pay to bike down it daily.
When it was the main highway the annual road toll for the death road was believed to be more than 300, a little below that for the whole of New Zealand (350-400) in the past few years.
We had been in La Paz for less than two hours before we were in the Gravity offices booking a tour for the next day. The company has a reputation for offering the safest, most organised tour of the Death Road.
New Zealander Alistair Matthew started the company more than a decade ago and continues to run it as owner/operator.
Bored with an office job in Wellington, he headed overseas for adventure and saw a unique opportunity to turn his love of bikes into a business.
Gravity was the first company to commercialise tours on the Death Road.
Luckily for us, Matthew was one of the guides for our tour. With his long beard, tattoos and laid back attitude it is hard to imagine him behind a desk.
The tour began at a coffee shop in La Paz. A roll call is taken and the dozen people in our group pile into a van.
An hour later we arrived at La Cumbre, 4700m above sea level. Even the fittest were feeling the effects of high altitude.
We were given bikes, helmets, safety vests, pants, jackets and gloves. Weighing five kilograms more and wobbling around atop a bike for the first time in years we practised on a stretch of paved road.
To appease the gods we sipped a foul tasting alcohol and poured a little on the front wheel of the bikes. I wasn't convinced about this preventing accidents but the look on everyone's faces when they tasted the drink was much needed comic relief.
Then the questions started.
Has anyone every died doing this? Yes. Only one with Gravity - a middle-aged American man crashed and fell off a cliff. No one was near him and it remains a mystery why he crashed.
There is another common tale among travellers, about a woman who rode off the edge of the cliff, and kept peddling in mid-air. Matthew told us the story was partly true. She was pulling into a rest stop with the rest of her tour group and her brakes failed and she went over the cliff.
Her story highlights one of the major dangers of the road - unsafe tours.
In the 10 years since Gravity started numerous other tour groups have sprung up. Some are ok, but others have little regard for safety. It pays to check out any company and their bikes before handing over cash.
After riding through a drug check point (ironic in a country where the cultivation of coca plants for cocaine production is an economic staple), there is a slight up-hill section before the real Death Road began.
It was unpaved, narrow, windy and steep. And that's without mentioning the dramatic cliff we were riding along the edge of.
Following heavy rain there had been several severe slips on the road. The van was unable to follow us down and we were on our own without some of the safety gear or the option to sit out sections of the ride.
It was then we realised the seriousness of what we had signed up to.
With no other option we lifted our bikes onto our shoulders and began trudging through a section of washed out road. A waterfall cascaded over our heads as we sank knee-deep in mud and debris. It was actually quite fun.
The ride took more than five hours. There were regular stops for water, food, photos and safety information.
We had to ride for longer than normal because the van could not get in to meet us at the bottom of the road.
By the end of the day we were down to 1000m above sea level. We were hot, tired, dirty and feeling extremely smug having survived the trip without serious injury.
A few came off their bikes and there were those who had cramp in the fingers from gripping the brakes.
But, overall, we were unharmed and happy to have escaped the clutches of the Death Road.