Great results without great expenditure
I ordered a BBS02 mid drive kit from Luna Cycle in October of last year. It arrived within a few days and, since I had done considerable research beforehand, I was able to install it in a few hours. I’ve been enjoying it ever since.
I chose the BBS02, rather than a BBSHD, due to cost considerations and expected ease of mounting, due to its smaller diameter flange. For power I chose a Luna Mighty Mini 30Q, for its reasonable cost and small form factor. Another consideration was its 30A continuous BMS, which will make it perfectly adequate if I should upgrade to a BBSHD.
Initially I was considering a fat tire bike build with a BBSHD, but a test ride on a fat tire bike at a bike shop convinced me I didn’t really like the feeling of the 4” wide tires. I still wanted a little wider tire than a regular mountain bike tire so, with cost an issue, I purchased a Mongoose Hondo 27.5 plus tire bike for the bargain price of $179.95, shipping included. I knew it would be fitted with all the cheapest components, but what the hell, I knew right at the start of the conversion I was going to throw away the guts of the bottom bracket and the front derailleur. The bike came fitted with mechanical disc brakes, which helped make the conversion easy with the Bafang handbrake levers purchased from Luna. Contrary to some reports I’ve heard on Mongoose disc brakes, mine were easy to adjust and work great, with the Bafang levers installed. I’ve since upgraded the rear derailleur and replaced the twist shifter with a Shimano trigger shifter. I also replaced the 14-28 tooth freewheel with an Epoch 11-28 tooth freewheel because I was running out of gear when pedaling hard on the level. I have the 46T chain ring and I ride mostly on a paved bike path and public roads, by the way. Before installing the new freewheel I rearranged the gears for fewer shifts. See this link: https://electricbike.com/forum/forum/knowledge-base/motors-and-kits/39170-how-to-rework-rear-sprockets-for-mid-drive-systems
One caution: with older, cheaper freewheels, like mine, you have less ability to rearrange the gears than you would with a more modern cassette. That’s a drawback of the cheap bike which is not so easily changed.
For those who don’t know, the 27.5 plus tires are 2.8” wide, compared to mountain bike tires at about 2” wide and fat tire bike tires at about 4”wide. I think that’s a nice compromise on an e-bike, very solid, but still that nimble feeling you expect from a bike.
The bike I bought has a 68mm wide bottom bracket, which was great from a cost-cutting perspective, because it enabled me to use the BBS02. It might be a bit more challenging to install a BBSHD, which, I believe, has a bigger flange than the BBS02. I had to shim the BBS02 out slightly because the flange was hitting the chainstay, which flares out to accommodate the rear tire. I expect the BBSHD would need more shims and then probably the appropriately dished chain wheel to correct the chain line. That assumption also influenced my decision to buy the BBS02. I’d be interested to hear from anyone who’s installed the BBSHD on one of the 68mm BB Mongoose plus tire bikes, which BBSHD width and which chainwheel they used.
Would I like the extra power of a BBSHD? Sure, but for the moment I’m really loving the BBS02. One thing that has surprised me is that I’m seldom inclined to use the throttle. I expected to prefer the throttle over pedal assist, but it turns out, for me at least, it’s much more fun to pedal. I’m 68 years old and it’s great to fly at speeds I couldn’t even achieve when I was young.
At some point I will upgrade to a BBSHD. I’d be more eager to do so if Luna would make their ludicrous option available in a bare motor for upgrading. Luna, are you listening? I’m somewhat seriously considering chopping and welding my frame to mount a Bafang Ultra, which they do offer with the ludicrous option. That might make my throttle more interesting! For now I’ll just keep enjoying my bike and save my money for that eventual upgrade.
Thanks Luna and Bafang, for a great product. I’m looking forward to sampling some more. And to anyone who’s been considering an e-bike build, just do it. You’ll love it!
Mike Peacock 1/24/18