Re: the 72 miles on a road bike vs the other bike, is the main difference in expected mileage down to the weight of the bike or wheel size, or what? Thanks
The 'other bike' is a mid 90's Trek non-suspension MB with 32mm Schwalbe town tyres, as ridden it weighs about 21kg. My test on that bike included boosting the assistance setting towards the end of the ride because it was getting weaker presumably because the battery voltage was dropping. It was a first look-see at range limitations because I too plan to tour on an ebike, The result was still remarkably close to the Bosch calculator results.
My more recent assessments have been with 'other things equal'. That is..
same 17kg bike and battery
same 85kg rider [me]
very similar route that has about 450m of climbing over 72miles, [the River Severn has occasionally got in the way of late]
same reasonable weather, I don't like high wind and rain.
level 2 72miles, level 3 54 miles, level 1 TBA
The battery starts fully charged and I ride it to cut out, hence the last few miles are inevitably in town to avoid a shock to the system riding an unassisted bike for miles
I've got a Hailong 10.2A-hr battery on both my bikes. These are 10s4p units [40 cells, 10 in series, 4 sets in parallel] to yield nominal 36V battery. Larger 10s5p batteries are available, I don't need this level, so didn't go that way. Weight goes up obv, but so long as it's positioned on the down tube it's not noticeable. I've attached a bottle cage to the top of the battery case since that's the easiest to reach when riding. Larger batteries than a 10s4p may make this tricky. depending on frame size.
Rear rack mounted batteries upset the balance of the bike IMO.
Hope this helps..