BBSHD build: Motobecane Sturgis Bullet

[JPLabs]

This is my first eBike build, a mid-drive fatbike. I installed a BBSHD and 20 AH Panasonic ICR18650PF Triangle Pack, both from Luna Cycles, onto a Motobecane Sturgis Bullet.

Others with the same or very similar motor/frame build combinations are welcome to add your own builds to this thread, if you like.





Below, note left thumb throttle replaced the front shifter. That is not a sleek looking looking or comfortable throttle lever, but it isn't horrible, either. I'd like to eventually replace it with the old shifter lever:



This is not the first such BBSD/Sturgis build - MountainTime posted a very similar build here, a couple of weeks ago. I owe him thanks for his advice and help with dimensions, such as confirming that a medium frame could fit my triangle pack, and that a 100 mm BBSHD would not quite fit this frame without shimming and an offset left pedal. Thanks, MountainTime!

His build thread link: https://endless-sphere.com/forums/viewtopic.php?f=3&t=75847&start=25

This bike is a blast to ride. The modified BBSHD controller calibration provided by Luna works well. I put a 30T Mighty Mini sprocket on it from the start. I only have 5 miles on it, at sunset last night, after finishing up the build. I was in PAS1 most of the time - it is the highest PAS setting I can keep up with, pedaling for real to help. I plan to re-calibrate to make 2 or 3 of the 9 PAS levels usable with pedaling, with that small chainring. I was not disappointed by how quiet and powerful this drive is, and I'm nowhere near maxing it out yet with my riding so far. Tire knobs drown out the drive noise, which itself is very smooth and pleasant sounding. Sweet!

I chose this model bike in particular because it comes with a ($600+) Bluto fork and has a relatively open frame triangle for battery clearance. It also comes with nice components such as Mulefut tubless-ready clincher wheels, and Snowshoe tires.

I chose the 120mm BBSD kit. I wanted the crank arms centered on the frame. The right side pedal clearance is set by the motor, and nearly all the shimming was on the left side, so a 100 or 110 mm kit would have resulted in the same pedal spacing anyway, if I added a offset LH crank arm to get the pedal spacing symmetrical. You need to cut off about 5mm from the front derailer mount on the frame to center the install (motor just touching rear triangle) and to get the best chainline. That 120mm kit fit very nicely, with only shimming, once the shifter bosses were shortened.

 

[JPLabs]

More pics:



Drive side spacer:








Not my girly hands!




The bike is a lot of fun. We are expecting 6-12" of snow this week, hooray!

My frame is from Bikes Direct. It showed up within 4 days to Michigan, with one small chip on the forks, but that is no big deal to me. I called their customer service with another question, and got to talk to a nice human right away. So, they seem like a good source for the donor bike.

I got most of the other components for this build from Luna Cycles - I learned of them here, and it was a good recommendation. Service was great and they have a nice selection of parts stocked in the USA.

I plan to replace the watt meter seen above with a Batt Man battery and power consumption monitor, but other than that, I'm happy with my component selections.

This was not a difficult build by any standards, especially by Endless Sphere standards, where members are known to conjure their own motors out of iron, copper, and magic! It's mostly a kit assembly job, with a few custom spacers needed. I did it in 2 days, and a lot of that time was spent double checking dimensions, deciding how to execute packaging, or soldering. If you can turn a wrench and solder, and don't do anything foolish with wiring the 52V system, you can probably put this project together with no issues. Do get the proper bottom bracket tools unless you are ok with mangling parts.

I think the combination of the Sturges Bullet and BBSHD is a wonderful first build, and it didn't leave me wanting for more. Yet! I'll dig into custom programming soon.

If you interested in full details of this build and want to learn more, I did a fairly extensive write-up, but I didn't think I should duplicate all of that here in the gallery. In the full build thread I've included a lot more photos, and details like frame size and riders that can fit this bike, wiring routing, dimensions for needed spacers, and such, here:
http://electricbike.com/forum/forum...motobecane-sturgis-bullet-20-ah-triangle-pack.

 

[craneplaneguy]

Excellent timing JP! I picked mine up today, as always UPS just missed Friday, so I had to wait all weekend. We have the same color....I picked it for stealth purposes. I unpacked everything and started right in, getting a head start by having a local bike shop pull that BB for me for 5 bucks while I waited, money well spent I decided after an hour of messing with it the day before.

One quick question: the rear shifter cable housing, did you leave it where it was or re-route it? Not sure but it seemed like it may be in way where it was, I just glanced at it late today.

Where I'm at: fabbing the final shim/spacer tomorrow AM, similar if not the exact clearances as yours. If I don't get a call for crane work I'll probably be able to test ride late tomorrow, with the battery in a backpack for the time being. I feel like an old pro after my Montague build, it's much less intimidating anyway the second time around.

 

[spinningmagnets]

Luna also has a battery bag with eyelets so the builder can use zip-ties, but the Velcro bag is more water-resistant, so...good call.

If you ever decide you want a suspension seatpost, the top two I've read about are the Thudbuster, and the Suntour NCX

 

[soaresdacosta]

Nice build, nice details. Well done.

Luís.

 

[waynebergman]

Wow! This is such a nice fat bike. Do you mind giving a total price for its completion. It looks like a great bike to duplicate for someone wanting such a bike. I love the the tubeless tires &the bluto shocks super nice. It would be great to get updates on the Blutos as you put miles on them. One recommendation I would make but its not for everyone, I just prefer the 1/2 twist throttle right side as I am coming from a MC back ground. What I did is I took the Bafang twist throttle and ran it through my band say cutting the length of it down to a min. I am used to running my brake levers way inbound anyways so they don't really come into the way and then I just shave a 1/2 inch or so off of my reg right side handle bar grips. Then I just run my throttle with a very light touch from my right thumb and fore finger. Its very doable and you get great control but like I say its not for everyone. Good luck, I hope the snow experience is awesome for you.
I am guessing with the mini 30 tooth you will just be using the outbound one half of your rear cog set for good chain lines and also working cadence?

 

[JPLabs]

Great! Have fun with it. Is yours a 120mm kit?

For the rear shifter cable, I think I know what you mean - it routes under the bottom bracket, on the RH side of center, so it winds up between the motor and the BB. I was careful to keep it as far to the right as I could, and it works well there. There is enough clearance so it is not pinched. Stock routing worked OK. Here's the way mine was routed - it's the bottom cable in this pic. The top cable in this view is front shifter, which gets removed.



I recommend you grind a little material from the motor boss where it contacts the frame, so you can get the motor mounted as high as possible, unless you are worried about voiding the warranty. Better for ground clearance, and better looking, IMO. It made a pretty big difference with this frame. I painted it black after the rework - a black Testors paint pen is a handy thing. Like this:

Excellent timing JP! I picked mine up today, as always UPS just missed Friday, so I had to wait all weekend. We have the same color....I picked it for stealth purposes. I unpacked everything and started right in, getting a head start by having a local bike shop pull that BB for me for 5 bucks while I waited, money well spent I decided after an hour of messing with it the day before.

One quick question: the rear shifter cable housing, did you leave it where it was or re-route it? Not sure but it seemed like it may be in way where it was, I just glanced at it late today.

Where I'm at: fabbing the final shim/spacer tomorrow AM, similar if not the exact clearances as yours. If I don't get a call for crane work I'll probably be able to test ride late tomorrow, with the battery in a backpack for the time being. I feel like an old pro after my Montague build, it's much less intimidating anyway the second time around.

 

[JPLabs]

Waynebergman,

Thanks!

I'm at about $3300, all in, counting the charger and all accessories, connectors, wiring, lights etc. Includes a couple tools I didn't have. That includes the tubeless conversion tape, valve stems, sealer. Almost half the cost is for the donor bike, which I am real happy with.

I added a parts list with prices and vendors, and links to main components uses, in the full detail build thread I linked to above, if you want more info about the costs. Here's that link again:http://electricbike.com/forum/forum...otobecane-sturgis-bullet-20-ah-triangle-pack.

Bluto seems quite good so far, but I haven't been offroad more than 1/2 mile yet. Just curbs and a couple of logs. I can't feel any sticking in it's travel; it slides perfectly smoothly. Seems rigid. I weigh 140 lb and have sag set at 30 % right now for cushy ride. My motorcycle rear shock suspension pump fits this fork, used to add or subtract air to set sag. There is a sag gauge on the fork tube, and even an o'ring pre-installed to check travel. Nice bit of kit!!!.

I also have a motorcycle background, enduros. Twist throttle sounds nice. I might try that suggestion. Thumb is awkward. I may switch the brakes to moto style as well (front belongs on RH side!)

Wow! This is such a nice fat bike. Do you mind giving a total price for its completion. It looks like a great bike to duplicate for someone wanting such a bike. I love the the tubeless tires &the bluto shocks super nice. It would be great to get updates on the Blutos as you put miles on them. One recommendation I would make but its not for everyone, I just prefer the 1/2 twist throttle right side as I am coming from a MC back ground. What I did is I took the Bafang twist throttle and ran it through my band say cutting the length of it down to a min. I am used to running my brake levers way inbound anyways so they don't really come into the way and then I just shave a 1/2 inch or so off of my reg right side handle bar grips. Then I just run my throttle with a very light touch from my right thumb and fore finger. Its very doable and you get great control but like I say its not for everyone. Good luck, I hope the snow experience is awesome for you.
I am guessing with the mini 30 tooth you will just be using the outbound one half of your rear cog set for good chain lines and also working cadence?

 

[JPLabs]

All I rode more tonight. We have about 5" of new, heavy, wet snow. I needed all the gears, mostly the lower ones (biggest rear cogs). There was plow spray along the roads, with big chunks, still soft. I powered through a lot of it in 1st-2nd gears, PAS1, on the right-of-way and/or sidewalk, hard to tell. Throttle was very helpful to get started if I stopped in the deep muck. eBrake was pretty critical, as sometimes the rear wheel would start to spin, and the PAS cutout takes a bit long. Easier not to crash with the eBrake to shut off PAS. That was starting with about 8 PSI. I dropped both tires to 3.5 PSI and the traction got better, and the handling less squirrely. I used up to 5th gear PAS1 on the virgin 5" snow zones, as opposed to along the roads, and that made for smooth cruising. Used up to PAS3. About 14 mph was plenty in that slushy snow.

So fun.

So, to answer your question Waynbergman, I wasn't sure before if I would use all 10 gears. But today I learned that all of them are useful, as sometimes when kareening through slop piles, low speed and high wheel torque are best. Until I develop my 'snow dance' steering reflexes a bit more, anyway.

Also, I had a hard time modulating the throttle at low power; I think a twist throttle would be better for dicey riding, you were right.

 

[JPLabs]

Few more pics:





Once I got home, I dropped the seat and hooned-up my own back yard. 3-4 gear, throttle. Would wheelie, would drift! 14 mph tops I think. Spent 15 min tearing up the snow, no harm to the grass.