My wife and I rode about 700+ training miles the first year we rode (between early April and mid June). It turns out we probably over trained.
Last year we did not get as much in, but we did fine. I bike commute daily (10 miles) and we could do a 25-50 mile ride on one weekend day if possible. It's not a killer tour (BNW) but some 'butt' time is key. If you can get a couple rides of 50 miles or so, that will get you close to an average day
I try to train for this type of tour as I would train for a century. I Increase my weekly milage about 10%. I ride 4-5 days/week. So, this week for example I'm riding 57 miles/day. Up hill, down dale and into the wind (oh yes ! lots, of wind).
I see no 'new rider questions' so I'll give an old rider answer to the unasked question.
A good objective for new rider/tour training is to set your daily average at about half the tour average mileage.
Somewhere I read that the national tour daily mileage average is 66 miles per day. So aim for two or three hours on the bike on an average day (2 or 3 hours x 15 or 10 mph = 30 miles).
Ride a tour at 60-ish miles per day with this preparation and the first days will be tolerable and at the end pleasant.
