The couple love taking people into the back of beyond and choose their rides for the views they offer. But I'm not just after scenery - I'm wearing an Icebreaker singlet, and the baa-code tells me its wool comes from a merino grazing one of the stations we'll pass through.
I may be the only sheep-spotter among the 80 riders who start out at Twizel on a range of bikes, from a Honda farm hack through a flotilla of Yamahas to a shiny big BMW R1200GS.
We follow a pylon track across rolling farmland, then a network of back-block gravel roads leading to the Clay Cliffs, their naturally formed white spires reminiscent of Utah's red pinnacles.
We're heading for Haldon Station, tough country that gets just 300mm of rain a year and rises to over 1500m, with rocky ridges overlooking Burke's Pass and supporting hardy flocks of merino, Hereford cattle and red deer.
My riding companion, Emma, and I take an optional "challenge" loop on to the ridgeline, accessed via a steep switchback climb rendered a tad more challenging today by high winds that occasionally threaten to blow us into Burke's Pass and beyond.
We're too busy keeping to the track and avoiding view-induced vertigo to look out for sheep, and when we descend to the river valley we're ravenous for lunch at the tiny white weatherboard Haldon School.
The parents of its five correspondence school pupils cooked up a storm to raise funds to help pay for a teacher and we did justice to the hearty spread.
Mike says he relies on country schools to supply lunches and source terrain for his rides.
"The parents are the local landowners," he says, "and if we put money into the school we're almost guaranteed access."
And a few stories.
In Mackenzie's day claiming land meant registering it - and proving you could run a sheep per two acres within two years. We're told arriving inspectors would be fed and watered royally each night, while out in the darkness men moved sheep from a surveyed block to an uncounted one.
After a relaxing night at Tekapo's Peppers Bluewater Resort we thread the Orari gorge on a narrow track clinging to rocky defiles, clambering up inclines or plunging to ford tiny streams.
The land opens out as we ride through Lake Heron and Glenfalloch stations, past tussock-clad hills formed by ancient ice sheets.
In the distance, the Arrowsmith range looms and steep gravel fans punctuate the valley slopes.
This landscape dwarfs our bikes and scattered sheep seem lost among the tussock. Farmers muster by helicopter here, and many stations are run by married couples working alone for much of the year. As we stop, we realise we cannot hear another human sound.
I'm still scanning for sheep. Lake Heron Station harvests 50 tons of merino wool each year for Icebreaker. Among these rocks there's a sheep responsible for the T-shirt I am wearing. But feed is hard to come by here, animals are widely dispersed and scanning the wilderness, I don't spot them.
Our last day dawns damp for the return trip up the gorge for lunch at the 128-year-old Albury school, with its team of cooking mums.
Then comes the long gravel traverse towards Mt Nessing.
Mike assures me it's "not too steep" and the surface is "shingle". Clearly he needs glasses. In places it's more vertical than flat, with scattered rocks to trap the unwary.
But he promises the views are worth it, and he has placed helpers all the way up the tricky zig-zag to the summit to provide an encouraging shout or a push where required.
I'm not a regular off-roader and at first feel intimidated, but passed by a couple two up, then a pair of white-beards I stiffen my spine, shout "banzai!" (hope no one heard me) and twist that throttle. It works; the bike and I scramble up until I stop for a break near the top, next to the oldest rider who this year celebrates his 81st year. He's taking a breather and admiring an endless view.
I'm tired and reluctant to take the slow switchback down to the rocky river paddocks and the farm roads heading home. So I take a last break at Dog Kennel Corner to remember pioneer times when this was a station boundary in the days before widespread gates and a lonely dog held stock at bay. Now it's just a tiny junction off the main road south, missed by most travellers zipping past.
It's not all they're missing. New Zealand may be famous for adventure tourism, but few of those throwing themselves off bridges and cliffs or jetting up rivers will have earned their views like we did.
IF YOU GO
The Brittons run adventure rides throughout New Zealand, often on land not usually available to the public. Some are suitable for larger dual-purpose bikes, and two-up.
You do need some motorcycling experience. Mike and Angela are happy to advise you on how to get started, but suggest you don't try the three-day Safari until you've done some shorter rides.
Look up nzbike.com if you don't have an adventure bike or need another for a guest to ride. They rent BMW adventure bikes suited to more experienced riders. For more, see adventurerides.co.nz.
If adventure rides sound too tough, take a gravel-road tour. The website biketoursnz.com rents dual-purpose bikes if you want to DIY, or opt for its 23-day Dust and Delight guided tour.
We rode Yamaha WR250R road-registered trail bikes, courtesy of Yamaha New Zealand, which can be lowered a tad to suit shorter riders.
