We take our own bikes.
We have always used hybrids. The gear
ratios on our new bikes (Glen's pictured) were too high,
but our bike shop swapped it for mountain bike gearing.
The lowest gear should be 1:1 ratio
Apart from that, make sure the wheels
have good quality spokes and are properly
built. If they don't, get the wheels professionally
rebuilt with quality spokes.
We found this out the hard way. I found several broken
spokes, on the drive side of the rear wheel, in a small
town on the west coast of New Zealand. There was a bike
shop, but it was closed for Christmas, and we had to
take a shuttle bus back to the east coast. The shuttle
bus went a very indirect route so we missed two days