St Arnaud to Blenheim
If you do not wish to travel the Rainbow Road, try this route east to Blenheim. It's a quiet, rolling day that rises briefly for a few kilometres out of St Arnaud and then strolls slightly downhill all the way to Blenheim. It's a good road with the wind behind you and the scenery is quiet and pastoral and there are a few interesting bridges and shingle streams. You can cover some long kilometres very quickly on this road and in good conditions you can make up to 25-26 kilometres an hour depending on your legs.
There are no stores until the pub at Wairau Valley, although there is a basic DOC camp at Kowhai Point (toilet and water tap, but water must be boiled). Stop at Renwick, 10 km this side of Blenheim and immerse yourself in the wine growing area of Marlborough. Enjoy yourself!