Rawene to Cape Reinga
This is an easyish day through rolling countryside. Once off the ferry it is a quick, flat ride into the village of Kohukohu. Although smaller than Rawene, Kohukohu is every bit as picturesque and offers several good cafés, galleries, a store, library and camping.
Quiet country roads take you onwards to Broadwood (store, toilet). At Herekino (camping at the pub 1 km down a side road) you can see how the next 15 km will unfold, as you pick your way through the few remaining hills to the small settlement of Ahipara at the base of Ninety Mile Beach. Here there is a café (pricey), mini-mart (also pricey) and a dairy/takeaway. The campground is about a kilometre down the road and also has a small rudimentary store.
If the tides are favourable and you want a bit more ride out of the day then you might consider cycling the 15 km to the next campground at Papakauri.
Despite its name, Ninety Mile Beach is not really 90 miles long; it is actually just 55 miles (about 90 km). The origin of the name is unknown, though there are several theories, including this from wikitravel.org:
It got its name from the estimate which the early farmers in the area used when bringing their cattle to market. They figured they could drive their livestock 30 miles per day and it would take them three days to make the trip from the top to the bottom of the beach. Thus the ninety mile name.
For roughly 3 to 3½ hours either side of low tide the beach is eminently rideable as the sand is compact and hard. If you can, try to plan your trip to coincide with a favourable low-tide time so that you have enough daylight hours to complete the ride. Apart from the campground at Papakauri there are no services en route.Although initially a bit jarring traipsing with your bike through the soft sand to the water's edge, trepidation is very soon replaced with delight at the novelty of riding along the beach. A beautiful sunny day; a zephyr of a tail wind; what could be better?
Actually, the novelty does wear off and by about half way I'd fished out my MP3 player to help break up the monotony. Those cyclists with internal gearing will be thankful for their setup because sand unavoidably gets everywhere - but this route is still by far preferable to Highway 1 which has no road margin, is longer, undulating, and attracts a surprising volume of traffic.
At around 80 km from Ahipara you turn up Te Paki Stream, joining the roadway which leads to Highway 1 for the last push up to Cape Reinga (or Te Rerenga Wairua meaning leaping-off place of spirits) where there is a walkway to the iconic lighthouse. The nearest campground (the most northern in New Zealand) is the DOC camp about 5 km away at Tapotupotu Bay. A beautiful spot, but the mosquitoes are fierce!