Ask an ebike technical question get an answer within 30 minutes or so.

[Daniel Wolf]

Sorry - re-read the lead in to this thread (my question is larger than a quick tech question).

[HIGHVOLTAGE]

Eh, we've answered some pretty large questions before. It's not a strict enforcement. Give it a shot if you want.

[Giraffe]

Can you tell me what is the smallest number of teeth on a BBSHD-compatible chainring out there that still gives a reasonable amount of offset toward the bike frame centerline? I'm looking to convert my mountain bike to a Luna ebike, but I'm concerned about the low pedaling cadence I would have when climbing singletrack hills with a 42 tooth chainring. I did a number of measurements on my bike, and I think I would need at least 15 mm of offset with the chainring of choice.

My bike is a Specialized Epic full suspension size XL with 26" wheels and a 9-speed 11-34 Shimano HG50 cassette. Thanks for your help!

[paxtana]

Smallest number is 42. It is explained on this page along with methods of using smaller rings while still having good chainline

https://electricbike.com/forum/forum/knowledge-base/motors-and-kits/bbshd/20359-bbshd-chainring-offset-guide

[Giraffe]

Thanks paxtana. Yes I had read that well-written chainring offset guide discussion. In your experience do you find that people can climb steep singletrack hills with a 42T chainring and a 34T largest cassette cog? On the steeper hills with my non-powered mountain bike, I struggle along at 2 mph with my 22T inner chainring. With a 42T ring, I'd need to be moving almost twice as fast to maintain the same cadence.

[HIGHVOLTAGE]

If it's really steep, you'll probably need a lower size like 30T Mighty Mini, but chainring offset will come into play and you'll probably have to make some decisions about whether you want a straight chainline vs having more torque. My first build uses a 30T with an awful chainline which makes a bit more noise when it runs, but I don't mind it that much since I'm more concerned with torque output.

This might also be helpful for you:

https://electricbike.com/forum/forum/knowledge-base/motors-and-kits/39170-how-to-rework-rear-sprockets-for-mid-drive-systems

[paxtana]

Worth noting that bbshd puts out more three times the peak power that the world's best bicyclists can provide. It's not going to be a problem for the motor in most instances.

42 is not only the lowest you can go for good offset, it is also a sweet spot for optimizing torque while not making the chain ring need to spin so fast when the rear is in higher gears that you can't pedal along.

There's not much a 42t won't conquer and pedaling along when you are scrambling up a mountain is less of an issue than you would think, you provide the initial input and the motor just gives you a boost. Personally I would stick with 42 and just use a cassette with a big granny gear if it's that much of a concern

[MarkEbike]

I don't know how the shop did it but for regular conversion it depends how much length you need. Just a bit you can use "missing links". For more, might want a longer chain.

We also assumed these would be installed but they were only included so we changed the listing to reflect that.

I just was checking out the super moto kit, will Luna sell the 42T sprocket separately (or other sizes 38T, 40T...) ? What will be the loss/increase in toque from the stock 48T and loss/increase in speed using the new 17" rims or 19" original rims?

I'm already planning the next sur-ron purchase and saw the option with for the super moto kit for $300, will the original wheels be still included or do I need to pay the extra $119 (difference between kit price and upgrade) to have have two sets of wheels.

Thanks

BTW: Just finished my first 500km happy rides :)

[paxtana]

Hi Mark yes it will be sold separately. As far as I know the Moto kit should provide more speed, given that the sprocket is smaller. While the rims are also smaller which could in theory help make up for some of that optimization towards speed over torque, the tires are bigger which probably offsets a portion of that. I can't really say for sure one way or the other until we hear some customer feedback.

Not sure about whether the upgrade replaces the original wheel set or is in addition, I'll need to check with the warehouse on that and get back to you.

[Giraffe]

Thanks again paxtana and highvoltage. It sounds like I should be able to do just fine building up the bike with a 42T Lekkie or Eclipse chainring and a reasonably good chainline. Good to hear that slow rpms shouldn't hurt the BBSHD motor.

[paxtana]

If you are looking for a cassette with a granny gear for those super steep inclines might want to check this link https://electricbike-blog.com/2016/0...-granny-munch/

[ampoe2]

I am switching from BionX system to Bafang. Can I use my BionX batteries ( Battery: Li-Ion / 48V / 11.6 Ah / 555 Wh
• Torque (Nom./Max.): 25.0/50.0 Nm) with the Bafang motor?

[max_volt]

I believe so. If you look at the batt connector, it resembles a serial port with larger +/- pins.
Maybe a reason they are in receivership with no buyer interested.

[paxtana]

Ooo bionx just got roasted hotter than a lithium fire!

[max_volt]

E-bike burn. But really they had a good run in the sun but that sun seems to be setting.

[Coolo118]

I will be going to and from work on smooth roads 28 miles a day 5 days a week.

Do you know of a 29er rim that is tubeless ready, 36h, and can fit 12g spokes and a 38mm tire?

Do you know any other 29er rims you would recommend for my commuting meeds?

alex rim dm24 questions:

Do you know what the max spoke thickness compatibility on these rims are?

Do you think it would be safe to go ghetto tubeless on that rim with tubeless compatible tires?

[Kinni]

Rims are all about preference, tubeless is great as long as you dont get a true flat then youre in for a bit of a messy time. Alex rims are pretty OK. I ran one on my old hub motor pumping out 3k watts but I had a hard time with spokes breaking under that amount of stress. Mavic, CrossMax. Bontrager makes great rims, most rims will fit a 12g spoke nipple if they dont have eyelets but I found that 13g spokes work just fine if they are tensioned correctly. IF youre building a wheel for a hub motor, best of luck. I have to get away from that before i destroy another wheel...BBSHD all the way.

[paxtana]

You can probably go 13 gauge on dm24. It's not the spoke thickness but the nipples where it is a tight fit. Maybe you could go 12ga with a single butted spoke like sapim strong.

[Kinni]

Im running a 52v shark battery @ 14AH. (samsung 35E cells). Ive read the battery stuff on the Luna website and the chart there states some many helpful things but I was wondering, it says battery is at 0 percent at 42 volts, but the battery discharge cut-off is at 2.65v per cell making that 37.1v. I just charged my battery (to 90% 57.1v) and it took 7 Ah, but with the chart I was already at 30% left. The extremely inaccurate 4 light push-button "charge remaining" light showed ~ 50%. Am I not going to be able to use all 14 Ah? Not that I plan to. Can you elaborate on the chart vs. actual capacity?

[paxtana]

Well the chart's just a guideline, I wouldn't take it too literally. (there's a note about that on the chart)

When you get down to critically low state of charge the voltage is practically irrelevant, in practice if you keep pulling power you're going to see so much voltage sag it'll hit LVC even if the pack LVC is set several volts below 42. The lower the charge, the greater the sag.

To get a real idea of what your capacity is you would need to either drain it to LVC and measure how much goes in, or charge it to 100% and measure with a wattmeter how much goes out by discharging until it hits LVC. The latter is the more common way of testing it. Either way you probably want to use a wattmeter.

[vrobert]

Hi, I recently started to hear a clanking sound when riding, at first I thought maybe the magnet on the spoke was rubbing against the speed sensor, or that a spoke may be broken, but everything looks fine, the odd thing is that it only happens when I'm on the bike, and when I go at 20 and up MPH, if I get off the bike and spin the wheel i don't hear it, is this a sign something inside the bbshd is breaking? or can the sound be coming from something else? I cant figure this out, Please Help???

[AZguy]

All kinds of things can click, clack and clank and it can be very difficult to zero in on. I gave up worrying about most.

Spent weeks trying to figure out one creak that turned out to be the seat. Heard some clanking that turned out to be the lock. One of them that really had my attention and took a long time was a twanging that only occurred under high-power and high loads. That one really bothered me but turned out to be the spokes plucking across each other during the high loads although they are all properly tensioned >1000W is going to create some transient spoke stretch.

Like I say, after about 6000mi on my ebikes I stopped being concerned. If the sounds get worse then maybe they'll get my attention.

I ride 300-400mi/mo so I just make it a habit to toss the bike(s) on the stand once a week and touch fasterners and spokes and tighten anything that's loosening, examine wiring and connector conditions, give the chain some love and make sure the derailleur is happy...

YMMV...

[Joe Remi]

Make sure the motor is tight on the bottom bracket shell, and give the crank bolts a good tug. A general tightening session all around the bike - bars, stem, seatpost - is a good idea.

[rverstee]

Can you move the motor at all? I installed my bbs02 and [for reasons] had to take it off and re-install it. There’s the washer piece that has teeth in that goes against the BB and makes little dents in the bike’s frame for better grip. When I re-installed, I lined it up with previous dents in frame. After awhile I started to hear a clunk - there was a tiny bit of play in the motor unit. I took the motor back off, made sure the teeth on were over fresh undented metal on frame, and tightened everything back up. I cranked it a lttle past the torque rating listed on the nuts. Also made sure motor was up against frame before I tightened everything down. I’ve ridden hundreds of miles since without a clunk.

[Tommm]

Is the cyclone bluetooth 60A controller same as the bluetooth 40A but with a bigger shunt? Are they the same size?

[paxtana]

They are not the same, it's a different controller.

[Tommm]

Can you share the size of it?

[paxtana]

They are both sold out..

[robertgknight]

Hi. I want to drill two holes on either side of the center hole of the Luna Lander Suspension fork to mount a headlight bracket (see pointy arrows). Is this going to be hard to do, can someone suggest a drill bit? Thanks.

[paxtana]

Maybe it depends on the size of the hole? Doesn't seem like on the forks I have seen that have a hole at this point they are typically large holes. Maybe they keep it small so it doesn't affect structural integrity.

If we're talking adding cutting fluid might as well go with a dremel as well. Probably easier to keep it lined up and you can use the same bits at least for the pilot hole. Let the speed do the work, maybe use a dash of tap water for cutting fluid if the bit is getting hot, and try not to get any shavings on the stanchions while you're working cause that might mess up the internals.

[robertgknight]

Thanks so much guys. I am going to either still go this route or add a bracket to the light which will enable me attach it using just one hole. I'll post my results soon.

[Joe Remi]

You don't want a light there. The movement of the suspension will make it useless as a light, plus it will probably shake apart in a matter of weeks.

[noahp99]

Any idea when the Cyclone 3000W kit will be back in stock?

[paxtana]

About a week last I heard.

[bhaaf]

Can Luna reprogram a BBSHD Controller so it has the smooth linear throttle while peddling? To make it function like they use too. I feel they are too dangerous this way to let someone ride my bike. Try riding on a single track and touch the throttle and get full power, not safe.

[Joe Remi]

There's a giant thread around here about BBSHD custom programming, but if you're looking for a lower-power system so you can loan your bike out, this ain't it. My BBSHD bike is fast and nobody rides it but me.

[bhaaf]

I know how to program very well. Try this on your bike. In PAS 1 start peddling slowly and then start increasing throttle. Does the throttle increase the wattage slowly or does it go to full power. If your bike ramps to full power then you have the problem controller. No user programming can fix it. Seems to have been this way on the motors for a while

[paxtana]

Sorry this was a change made by Bafang and is not possible for us to change it. We have tried..repeatedly.