To make matters easy, my travelling companion was suffering a sore head from the previous night's holiday excesses and volunteered to ferry me and the bike to Horopito, and pick me up at Ohakune.
This is tourist country, however, and it's easy to arrange drop-offs and pickups. Kiwi Mountain Bikes owner Richard Chapman charges $30 a person for the drop-off and pick-up, on top of the $35 a person for bike hire, which is fair, considering the time involved.
The Old Coach Rd sets out over relatively flat farmland, giving my legs time to get used to the cycling and my brain a chance to get accustomed to gear changing. The route is 11km long - about 2.5 hours for most people - and not hugely taxing on the body.
Nor is it a race. Along the way, DoC information boards tell the story of the old road, which started life as a bridle track and was upgraded between 1904 and 1906 with setts (rock pavers) to make it an all-weather 39km connection between the two rail heads on the main trunk line.
More fascinating for me, was the rail history. Along the way I encountered two viaducts, which were major engineering feats of their day. The first, the 140m-long and 35m-high Taonui Viaduct, less than half an hour's cycling from Horopito, can be seen in its disused state.
But the Old Coach Rd doesn't have the benefit of a viaduct and the route drops steeply into the valley before fording the river and rising up the other side, leaving me, and the walkers I overtook, somewhat breathless. I stopped for a break and met another mountain biker who told me I was about halfway to Ohakune and there was much more downhill than uphill to come.
After a quick refreshment stop I took a white-knuckle ride downhill to the phenomenal Hapuawhenua Viaduct, which has been restored so anyone with a head for a 43m-height can walk across the 284m-long historic structure. You can also investigate a disused curved tunnel nearby.
Surprisingly, the Old Coach Rd was all-but forgotten until 2002 when DoC historians rediscovered it and investigated its history. Restoration started in 2005 and Prime Minister John Key opened the road last year.
Mountain biking in Tongariro National Park is becoming increasingly popular. But although I saw quite a number of other cyclists, the Old Coach Road isn't the most popular route for peddlers.
The Fishers Track, which starts from National Park itself, described as the next best thing to the Tongariro Alpine Crossing, is the biggest drawcard for the two-wheeled brigade, says manager Jason Cameron of The Park Travellers' Lodge, where we finished a perfect day in the restaurant watching the sunset over Mt Ruapehu. About 95 per cent of the 17km route is downhill, making it easy for beginners such as me.
The 42 Traverse is another route, favoured by experienced mountain bikers. It's a 42km-long remote track and is considered one of the North Island's best mountain bike rides.
IF YOU GO
Where to stay: The Park Travellers' Lodge, 0800 800 491.
Hiring bikes: Kiwi Mountain Bikes, 0800 562 4537.
Further information: See doc.govt.nz, ohakunecoachroad.co.nz and visitruapehu.co.nz.
Diana Clement travelled with the support of the Wades Landing Lodge, Kiwi Mountain Bikes and The Park Travellers' Lodge.
