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Mid Drive #1: BBS02 Fito Modena GT 2 Fat Tire Cruiser

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    Mid Drive #1: BBS02 Fito Modena GT 2 Fat Tire Cruiser

    Hi guys, avid ebike enthusiast and amateur builder here. I've built a number of DD bikes up to 3kW but always ended up saying "I should've built a mid drive!" That time has finally come!.

    Well, almost... Luna sold out of BBSHD's yesterday morning. I tried to place my order that evening. Ouch! BBS02 it is!

    The donor bike is a CL find-a Fito Modena GT2 cruiser. It has 24x3 tires, soft seat, soft grips, and smooths out every crack in the old sidewalks around here. 68mm BB with a 7 speed rear and disc brakes. I think that'll work for me.

    Parts list and approximate cost are outlined below. Hopefully this gives a prospective builder an idea of what to expect.

    BBS02 (750C, left thumb throttle, Luna Wrench) - $540
    Mighty Mini 30Q pack 52V - $300
    Luna shipping - $67 (multiple orders)
    Fito Modena GT2 - $180 (craigslist)
    7LED retro headlight - $19 (eBay)
    Thunderbolt 2.0 tail light - $35 (LBS)
    Harley bag - $10 (garage sale)
    Left side offset crank arm (+ shipping) - $30
    Pedals - $20 (LBS)

    Total: $1116

    Costs of fixing what isn't broken (Accessories and such!):

    Mighty Mini 30Q pack 52V #2 - $300
    Luna Shipping - $ 30
    Felt Thick Brick tires (+ shipping) - $79
    Rack - $18 (Amazon)
    Tool Bags for rack - $35 (Amazon)
    Lekkie Bling Ring 42T - $96

    Total (Extras): $556

    Grand total: $1672

    Here's the donor bike:

    Version 1.0

    Version 1.5

    Version 2.0

    Edited for clarity
    Last edited by moarpower; 07-15-2017, 08:29 AM.

    I love the cruiser builds! That should be a nice one when finished!
    that bike looks like it has a one piece crank. If so the bbso2 isn't going to fit without an adapter. Luckily we have a guy here that can get you one so don't worry.


      Well I feel like an idiot for overlooking that detail!

      So there is a 1 to 3 piece conversion for a 68mm bb that I can use to fit the BBS02? If so who would you recommend I contact?

      I placed the order earlier today for a BBS02 and Mighty Mini 30Q. Hope I didn't screw up lol!



        If this were a few months ago it would have been a big screw up, that's what I did! However I was able to find this guy on ebay selling an adapter for a different brand motor and he agreed to make one for me in the size that would fit the BBSO2!!! Since it was so nice of an adapter and I new others would want one I asked him to join the forum and he has been providing for us "idiots". I can tell you the workmanship is first rate. The guys forum name is "instigater". Here is the thread I started


          Awesome, thank you! I already sent him a PM about an adapter. Glad I didn't screw up! :)


            I asked the folks at Luna about my predicament and they have been helpful. We are still trading emails. I am still not sure if I will or will not need an eccentric cup after doing more reading on it.

            My BB roughly measures 2 3/16 in OD (55.6mm) and 2 in ID (50.8mm). I've read that American BB's are 56mm OD and 51mn ID so that seems to be about right.

            Hopefully the eccentric cups will fit if nothing else!


              If your inside diameter is 50.8 and the axle on the Bagang is 34mm you must use an adapter, its way too sloppy of a fit.
              Now the reason you need an offset adapter is because the clearance between the outside of the motor axle and the motor casing is only about 10mm. You can see if you have the Bafang axle sitting in the center of the 2 inch bb you are going to miss the 10mm clearance needed by a few mm
              Last edited by OptimusPrime; 05-20-2017, 03:28 PM.


                Study this picture of my bike. You can see the adapter in the bottom bracket and see how close the motor is to its axle


                  Excellent! I just sent payment for a set of the offset adapters. (Thanks instigator!)

                  The conversion is back on track, thanks again for the advice.


                    Just got notice my Luna order shipped! The adapters are in the mail too. Can't wait to get this thing going!


                      It's all here! I mounted the motor without trouble and hooked everything up to test for functionwhile the battery got a breif charge from 48.2V up to 52.2V. It works! Now I have to finish putting it together and find pedals! So close yet so far.

                      I will add pictures and a much more detailed post this evening but I had to share my excitement.

                      edit: It's all put together now except for the crank arms and pedals. The left side arm hits the frame where it flares out for the giant balloon tires. I need to order a non-drive side offset crank arm and Luna is all out of stock! Argh!!!

                      The good news is that the bike was wicked fast in the lower gears during the few test runs I've done. I'll never go DD again.
                      Last edited by moarpower; 06-02-2017, 03:28 PM.


                        I love unboxing!

                        The motor is so tiny! It's adorable and pure stealth.

                        The battery was a perfect fit in the Harley bag.

                        The whole bike was together before I knew it. I went to put the cranks on and d'oh! The left (non-drive) side needs way more clearance. Off to Luna's website for the offset crank arm and d'oh again! They are out of stock! Just my luck...

                        Mostly there!

                        I will update once I can get the correct non-drive offset crank arm and finish the job. I did scoot around the yard and instantly fell in love with mid drives.

                        So far I am very happy with this project and how it's turning out. I really like this bike.

                        Update: I did order the crank arm I need from empoweredcycles, sorry Luna! I'm just so ready to get this on the road.
                        Last edited by moarpower; 07-07-2017, 01:15 PM.


                        • Rider
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                          Looks really good! I sure like stealth battery packs so much better than the sharks and whales in the frame triangle.

                        The crank came in today. I got the battery up to 57.6V and sped off before an incoming thunderstorm. Holy heck this thing is fun and very light compared to my DD bike. That tips the scales at >80 lbs. This one is a meager 30-35 lbs and feels more stable yet more nimble. The weight is balanced properly front to back with a lower center of gravity. You can spank it in low gear and juke around everyday obstacles so quickly that it boggles my mind.

                        Besides my concerns about the longevity of the stock drivetrain, I do wish I got the HD. This thing is so much fun to push but I am inclined to baby it. The motor/controller barely got warm to the touch on my ride around the neighborhood in 85 degree temps. I bombed a few hills on PAS 5 but for the most part kept my speed under 20 with PAS 1 or 2 in a low gear (100-300w). I burped the throttle a few times and wow! If I could do that continuously and reliably I'd be one happy camper. But this bike was built to haul my kiddo's trailer up and down hills without murdering my legs, crotch, or butt. And it is perfect for that.

                        I do see a BBSHD overclocked to 40A on a downhill bike sporting a pair of 30Q mighty mini's in my near future.

                        Pic 1: Charging

                        Pic 2: With crank arms!

                        Pic 3: Left side offset arm
                        Last edited by moarpower; 07-07-2017, 01:17 PM.


                          First of all, great looking bike!

                          Love where you put the battery on the handlebars!

                          I used two of those bags as saddlebags to carry my mini's when I built this bike over the winter!


                            Thanks! I took a good deal of inspiration from your build. I had originally planned to use a pair of mini's in bags on the rear rack just like yours.

                            Despite the advantages, that would've blown my budget by about $400. Plus I'd feel like a copycat. So I tried to play off the vibe of the bike and work with what I've got.

                            In trying to keep it subtle the rear reflector under the seat was replaced with a thunderbolt 2.0 tail light. The headlight is probably the thing I like least about the bike. It's mount is crap and the style is pure "faux vintage" with a wimpy feeling switch to boot.