Biking in New Zealand - routes and hire company advice

[2seas]

I was thinking about hiring a bike to explore New Zealand next month. Can anyone can recommend a good company to hire with and/or fun routes?

[2seas]

BB never disappoints! Thanks for all the great advice.

I haven't booked my flights yet but I was thinking of flying into Auckland, working my way down and flying back out of Christchurch 2 weeks later.

I doubt I'll have the funds to stretch to a 2 week point to point rental (initially thinking pickup in Auckland and Drop off in Christchurch). Also there are so many other things to do I don't really want to be on the bike the whole time. Sounds like the best bikey stuff is around the South island so I may just wait until I'm there then hire a bike for a solid 3 days of riding...

Sounds like I may have to consider something a bit more versatile than a pure road bike. I've never been on nobbly tires before!