First of all, thank you all for your considered responses and enthusiasm!
I don’t think we’ve chatted before, so I must have a doppelgänger. There are a lot of bikers here in Portland, so the chances of someone else considering the same build, are not as great as you might think. My neighbor 2 houses down even has a Madsen!
I really like the idea of the BBS02 and being able to leverage the gears on the bike. But I’m still worried about the shifting. I’ve read reviews here:http://electricbikereview.com/8fun/bbs02/
where it has been mentioned that shifting under the load of the motor grinds the gears and can even cause the chain to break. It’s giving me images of my wife calling me at work because she forgot to let up on the motor when shifting, and needs me to come pick her and the kids up because the chain came off the sprocket and she can’t get it back on. Am I being too pessimistic?
That being the case, I’m leaning toward Dogman Dan’s strategy of getting the direct drive motor for it’s power and simplicity.
It sounds like the one thing everyone agrees on is that a 48v battery is the way to go. As Dogman Dan mentioned, it would be good to keep things as safe as possible with kids in the bike, so I was thinking of going with LifePO4. Does that make sense for this build?
I love Jonathan’s idea of buying a smaller battery (10ah?) to get the project going, and adding a 2nd battery in parallel. Is that just not technologically possible?
If not, could I buy one of these?http://www.ebay.com/itm/NEW-48v-15ah-LiFePO4-Battery-5A-Charger-BMS-For-Ebike-Kits-Powerful-8-Weeks-Gift-/131244468263
That would keep me withing my budget, even if I have to wait 8 weeks!
I would also consider building my own battery pack as mentioned in this thread, if it would keep the price down:http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=17912&start=0
I may be able to stretch the budget upward a bit if needed, but I do need keep the CFO happy so that I stand a chance of being approved for a 2nd bike project I'm considering, which would be a folding commuter bike.