120mm BBSHD build: Motobecane Sturgis Bullet & 20 Ah Triangle Pack

[JPLabs]

The front light came with bare wires, you do need to add a connector. If you don't want to solder, you can buy a connector with pigtails and use crimp connectors. Then heatshrink to waterproof it.

[JPLabs]

I got some miles on the bike and headlight tonight. 7 Miles if I can trust the odometer, but swear I only went half that or less. (EDIT: It was double-reading some times. I aligned the magnet and speed sensor better/closer and now it matches my Watt Man to within about 1%).

The 15W Luna Headlight works great to light up the world, that's for sure. I chose to aim it down quite a bit so as not to blind others; you can see the angle in the pics. I will try either a shield over the top, or some kind of different optic, so I can aim it higher and see farther, without throwing so much light up abov the hot spot. Any suggestions would be appreciated. 3 small optics, one for each LED, could also work.

Glare from the side is minimal.

I want to find something like one of these - this particular one looks too small for the Luna light, but the same idea: http://smile.amazon.com/gp/product/B...f_rd_i=desktop

While the light works GREAT, the LED color is pretty bad. Cool, slightly green tint everywhere except the center, with a very green tint to the center hot spot. It might not be noticeably on summer trails, but on the snow, it is obvious. You can tell in the first photo below - but it seems even more obvious to the eye. It is not a big flaw, and I'm very happy with the light. But, as a flashlight aficionado, I see opportunity for improvement. Someday I'll try to graft some nice warm-white emitters onto the board.

Taillight is perfect.

[Louis]

Nice build thread! Thanks!

[JPLabs]

I made a small mod to the bag to improve wire routing. With my setup, the BBSHD main controller harness lead from the motor was not long enough to route up into the top, rear wiring port of my Luna triangle bag, while still leaving enough slack up front to avoid damage if the handlebar gets rotated 180. So, I had been running the controller cable halfway up outside the back of the bag and closing the zipper on it. Adding a bottom wire port to the bag lets me run that cable inside the bag instead, with plenty of length. Now I can close the zipper any way I want to, the harness lead is almost entirely hidden from view, it is better protected, and I can still remove the bag if I want to without un-soldering anything.

I wired everything on this bike with connectors so the bag can be quickly removed - no soldered joints trapping the bag on the headlight/taillight wiring, for instance.

I simply heated a 1/2 steel tube up and poked it through the bag. The edges melted together and won't fray. Here:



Now, only the two motor power wires are routed outside the bag, to the rear top port. I put an XT90 on these, and they are still long enough for the external routing (barely). I didn't want to make the 1" hole that would be needed to pass the XT90, so I left that one as-is.

Simple and effective, and the hole is not visible with the bag installed. If I ever forget and leave my bag open, and get rain, this will let it drain so the bag can't fill with water.

[JPLabs]

The wiring is pretty much invisible now!

I also added an Ibera rear rack and a commuter bag, but this bag is awfully large!! It does not look very good on my bike, IMO. I'll mostly use a smaller bag on the rack unless I need to haul lunch and clothes.

Finally, I made a rear fender from flat 1/4 plastic I had lying around. I don't have very good pics of that yet, but it's visible below. Subtle.



The aluminum rack fits fine with the provided hardware, after a little bending to widen it. I needed to mount the RHS one hole higher than the LHS to make it level after I had bent the RHS out and centered the rack, otherwise it was not level as seen from the rear:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

The bag snaps on with a quick connect system. They offer smaller ones, but this has built-in panniers, so I picked it for commuting:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

[pfbz]

Awesome build thread... I'm just getting started with building my own ebike and this is *exactly* the kind of info I'm looking for.

Any lessons learned or things you would do differently? Happy with all your bike/motor/battery choices?

[Eric Luna]

Thanks for this in depth build thread....really awesome. I would like to give you a $100 Luna store credit as a token of appreciation. PM sent.


two quick comments i wanted to make...the Luna zip tie bag is a bit smaller than the velcro bag and i think a much cleaner look. It might fit just right in your triangle ...let me know if you want to try it I will send you one complimentary if you are willing to install it :)

Regarding the custom spacers you had to make....we realized lately that many customers must have this issue.

We just now made custom spacers and are providing them complimentary with every bbshd order.

You can find them in our store here. we have them in 1mm 2mm and 4mm sizes. The bbshd now come with a kit with a combination of the 3. 5 spacers total.

You can find spacers here

[JPLabs]

Thanks for this in depth build thread....really awesome. I would like to give you a $100 Luna store credit as a token of appreciation. PM sent.

Wow, Awesome! Thanks so much.

two quick comments i wanted to make...the Luna zip tie bag is a bit smaller than the velcro bag and i think a much cleaner look. It might fit just right in your triangle ...let me know if you want to try it I will send you one complimentary if you are willing to install it

I think a slightly smaller bag would be perfect for this frame, actually. Sure, if you will be so kind as to let me try one, I'll install it and show everybody how it works out.

Regarding the custom spacers you had to make....we realized lately that many customers must have this issue.

We just now made custom spacers and are providing them complimentary with every bbshd order.

You can find them in our store here. we have them in 1mm 2mm and 4mm sizes. The bbshd now come with a kit with a combination of the 3. 5 spacers total.

You can find spacers here

Now that is one of the best add-on's I can think of, as far as simplifying what is perhaps the most troublesome part of the install. I'm sure they will be popular. Good idea.

[JPLabs]

Awesome build thread... I'm just getting started with building my own ebike and this is *exactly* the kind of info I'm looking for.

Any lessons learned or things you would do differently? Happy with all your bike/motor/battery choices?

That's a smart question. Hmmm....

Here's one thing I learned:

Understand that PAS is like an RPM control for the crank/motor assembly. It sets your pedal cadence, and the gear you are in determines how fast you go.

At first I thought the stock PAS1 (now my PAS2) was as fast as I could comfortably pedal. That was in off-road-type, wet, snowy riding. Well, now I have gotten some riding on pavement, and stock PAS3 is easy for me, there. PAS4 not too bad. I can't sustain stock PAS5, at least not yet. I mean, I can't keep up while actually doing work. I'm not talking about 'clown pedaling' - you can do that at any of the higher levels if you want to.

--

I am happy with the bike, yes, no complaints yet. The only thing I really changed on it is that I cut about 1" off the seat post so it could drop further for smaller riders. Shifter needed adjusting, as received. Wheels are almost true, close enough. Little bit out-of-round, maybe 1mm.

Motor is just great; I was surprised and pleased that it really is VERY quiet, and smooth. Quiet was critical for me.

I'm really happy with the 20Ah 52V battery, also. Based on one ride with my new Batt Man today, it looks like I'll get better than 45 miles range with mild pedaling at around 16-18 mph (PAS 3-4). I say better than, because maybe 5% of today's ride was off road in snow deep enough that I couldn't pedal it alone at all, (600-800W used there) and at least 1/3 of it was on 1" slushy wet snow over asphalt. I used about 22 Wh/Mile.

I am aiming/hoping for 50 miles PAS range at 18-20 mph on level ground, and it looks like I may be able to achieve that, if not better, without the snow. And that's on floater snow tires at about 8 PSI. That should give you some idea how much battery you need for your goals. Keep in mind that the faster you go, the less range you get, so all range estimates are speed-dependent.

I'm glad I added a throttle; I got sideways and stopped in the heavy snow, and could NOT get going again without it.

Gearing impressions so far:

The 30T Mighty Mini chain ring is perfect for what I would call strenuous riding. Stuff like 6+" heavy snow which is too thick to ride on leg power alone, slower trails, or climbing hills that would be tough to pedal up. Anything where you want efficient high power (high motor revs) at a lower speed than you could dial in with the stock 44T chain ring. But for level, easy rolling surfaces, I think I might prefer higher gearing. I don't want to use the 'heavy iron' stock part, though. It looks out-of-place on my otherwise well-crafted bike.

For our mostly flat roads, I'm usually in top gear once I'm cruising, wishing I had a couple more shifts left. I mostly stay in high gear, and control speed/cadence with PAS. I plan to try a 42T Luna Eclipse chain ring for these easier conditions so I can pedal in PAS mode for real, at higher speeds and/or lower cadence.

Lower cadence means running the motor in a lower RPM, less efficient condition, but not so much as to be abusive if used rationally at 42T, I think. Meaning don't lug the motor at low cadence. With the 42T I will be able to use gears 7-8-9 more often, which results in a better chain line and reduced tooth loading in the rear, for improved chain & sprocket durability.

I'm not sure if 42T will be too much increase, or just right, for the way I ride. I'd probably aim for 36T as a next try, if it existed for BBSHD, but I don't believe it does. I might try to rig something up.

This motor seems very forgiving of gearing, so it's not critical, this is all about tuning preference. Chain ring size really only comes into play when you are in the highest or lowest gear. Think of it this way, if you wish you could shift one more time, think about changing your chain ring up/down in size as appropriate. That said, I am riding with ice water cooling right now, courtesy of my front tire. If I gear higher and pedal slower for the summer, I will be sure to monitor motor temperature to make sure I'm not stressing it too much.

For that easier, faster type of riding, I think I might like the 42T Eclipse chain ring better than the 30T. It will give me better top speed and/or lower cadence. It's pretty easy to change chain rings for different rides, if I want to.

[pfbz]

Thanks for the reply... Getting close to finalizing my order list and I'm leaning heavily towards a BD Sturgis Bullet with a BBSHD.

I posted a few questions on the other Sturgis build thread on ES that you referred to, going to ask some similar questions here:

Gearing: I want the bike to be multi-purpose... Maybe a snow bike (not my primary use), a mountain trail bike, and maybe even occasional flat land transport. Sounds like I should buy both the 30T and the 42T chainrings and see which works best in each application?

Battery: I was leaning towards a Luna Shark 11.5AH 52V battery pack instead of the bigger 20AH packs, mostly to keep the weight down. Any thoughts on weather it will fit cleanly on the Sturgis frame (medium, 17.5)?

Frame Material: I was also a bit tempted to splurge and get the new titanium Sturgis Bullet. Although the frames have the same name and listed as having the same geometry, there are definitely going to be some differences between a hydroformed aluminum frame and a round-tube titanium frame. I'm wondering if the fitment around the bottom bracket, chainstay clearance, etc. will be easier or harder with the titanium frame. Has anybody here seen the titanium Sturgis in person? Also, I'm worried that if I do have to do frame modifications like trimming the front detailer bracket, working with the titanium frame might be a PITA. Common sense says go with the hydroformed aluminum, but the idea of having a Fat, Titanium, Powered, bike just seems cool and different!

Bottom Bracket Width: Sounds like the consensus is to go for the 120mm bottom bracket width motor setup and spacers as needed, at least with the aluminum frame? Is it possible to alter the setup and convert a 120mm motor kit to a smaller width kit if needed?

[JPLabs]

Well, pfbz, I will answer the best I can.

Gearing:

If you want to ride trails and some snow, I think you might prefer the 30T for the torque. For me, I can now pedal up to about 22 mph while doing useful work, and 30 mph on throttle so far, without quite topping it out, with the 30T on pavement. Those speeds are based on speedo using wheel diameter, not yet GPS checked - I rode by a radar sign today that said 15 mph while my speedo showed 16, so maybe my speedo is a smidge high. Anyway, I think the 30T is pretty ideal except for low cadence, brisk cruising. I'm not sure I can say much more about it than I did above...

Maybe you should start with the 46T that comes on the kit, and see how it works for you. If you want way lower gearing for dramatically more torque in low gear, and slightly less top speed, then get the 30T Mighty Mini. If you are happy with the stock gear or want just a little less, but you want a super well made (cut from Billet 7075 & 6061) chainring, get the Luna Eclipse.

Or, if you are the kind of guy that likes to cover all options and have spare parts, like me, get 'em both!

(You can't really consider using the ugly stock steel sprocket on a TITANIUM bike, right? :cool: )

Battery:

I'm not sure if the Shark will fit, no, I didn't look into that one. Look at the published dimensions for that pack and mine. If it's smaller all around than the 52V Panasonic PF triangle pack, it will fit. If it's longer, though, take a close look at my build pics, I show my pack in the frame with no bag. If it's still too hard to tell, then I might need to measure my frame triangle opening for you, so you can make templates to check. I can do that, no problem, just not right now.

Frame Material:

Titanium is supposed to be real supple, like steel, only more-so, right? Nice riding feel, which is all the better on a hardtail frame. Beautiful and so cool to have. I covet titanium things - I didn't splurge on the Ti frame, though. Well, go ahead, make me jealous!

I think round tubes would fit the BBSHD better, if overall frame geometry is the same. That's because the widened downtube on the Sturgis interfered with the motor housing, where I removed material from a motor boss.

Do titanium and you might have the coolest e-Sturgis Bullet on the planet! For a while, anyway, until folks start following Eric's initiative and hot rodding them. Then, perhaps, we will have a wonderful little 'arms race' on our hands.

BB width:

I didn't find any downside to the 120mm. It's cheaper and more symmetrical than buying an offset crank arm to use a narrower kit. I like that I should be able to stick it on ANY frame. Although I can't see taking it off this bike anytime soon, I'm loving it.

I'm only aware of 3 'announced' MBSB/BBSHD builds so far. 2 of us used 120mm, the other (Mountaintime) used a 100mm, but recommended that wider would be better. So, pretty much a consensus, yes.

I think you would be #4. I should keep a list. In order, so far:

Mountaintime (ES, special kudos to the first one)
Me (here)
Craneplaneguy (ES)

[JPLabs]

pfbz,,

OK, here ya' go. Dimensions are INSIDE of triangle. 90 degree corner at seat. Tape measure, so not extreme accuracy, but pretty close.


Medium Size Sturgis Bullet frame inside measurements are 11" x 18" x 22.5".

[Eric Luna]

This excellent build thread was just posted on the front page of www.electricbike.com ... thanks again to JP LAB for such a thorough build reprort.

[JPLabs]

Cool! I'm happy to show an example of what's involved. As so many others have done, to my benefit.

Today I decided to install the stock chainring to see how it fits, and how I might like the ~50% higher gearing. I quickly found that the large Bafang sprocket will not clear the frame without shimming, with the motor in this location. I'm waiting on the chain ring spacers (sold out temporarily). Once I have one of those, I'll try it again. Washers could be used, or similar, but I'll wait for the nice Luna spacers.

So, take note if you plan to use the Bafang chainring, and probably also with the Luna Eclipse - get a chainring spacer. If that doesn't provide enough clearance, you could also offset the motor slightly to the right. There is plenty of clearance between crank arms and frame to allow it.

[JPLabs]

I've put something close to 100 miles on the bike now, and I've finally tried all of the PAS levels. With practice, when on smoother surfaces, I can spin my feet faster now, while still doing some useful work. You get used to it. The faster the bike goes, the smaller the steps between PAS levels seem. And, the motor programming is set up to dial back power as your pedal cadence approaches the set PAS speed (this can be changed in custom programming).

End result is that I can actually now pedal along in all PAS levels, if in 10th gear. It's easier if going uphill, into the wind, or if on grass. Conditions which load the motor and slow it down a bit. It's probably comical looking in PAS9, but it is possible for me to do now, when going up to about 24-25 MPH. The higher PAS levels are not as 'impossibly fast' as I thought before I had more experience with the bike. Remember, on my first ride in wet snow, I couldn't go above PAS1.

Normal cruising at 15 mph with medium pressure in these tubeless tires seems to require roughly 250W on pavement, using PAS in top gear.

I rode it to an extracurricular activity on the other side of town today. Several of the people there took it for test rides. It was natural and easy for them, due to the PAS with its simple control interface. It was great to see the beaming grins on every single face as they came back. One young lady summed up the experience perfectly: "I feel so STRONG".