A new internal gear reduction (no chain) mid drive announced

[ncmired]

Some more numbers, gathered from the CYC site:

• default for USA mode set at 1200w peak power
• USA / EU/ Canada/ unrestricted (2000w peak) power mode available via the app
• with its 13.3mm chain ring centerline offset from the righthand side of the bb shell, on a 68mm BB it should have a 47.3mm chain line

Regarding peak power, my guess is still that this motor won't be able to withstand 2kw (maybe not even 1.2kw) for more than brief periods (no long, high power hill climbs, especially in hot weather), but it will self-regulate (cut back) when needed. AFAIK, only one of the CYC displays (DS103) indicates the motor temperature, so with the other displays, if the motor starts to self-regulate you probably won't know it till/unless it gets severe.

I have one on order for the train bike (early adopter guinea pig sucker) - if it doesn't work out, back on goes the BBS02.

[Retrorockit]

What are you thinking for wheel size, gearing and cadence with this. What is the range fo chain ring sizes for this. the older one was limited.

[Retrorockit]

I looked it up. They have a 50t options so I'm good with that. I notice they TELL you how quiet it is, but play loud music on the video and have it on a bike with a very loud freewheel. So I don't exactly trust them on this. They say it has a sprag clutch instead of ratchet pawls. That would be nice.

[ncmired]

What are you thinking for wheel size, gearing and cadence with this. What is the range of chain ring sizes for this. the older one was limited.

Hi Retro - The wheel/tire size is 2" x 2.15. CYC's current chain rings are 34T, 38T, and 50T - all with the same chain line. Here's my 80 pedal assist cadence calculations with a 38 chainring and 18 sprocket, with a nice low 1st gear and striving for mid teens on the flats - on the low side of wind drag, and sipping on the 52v 17AH battery - hopefully:

The projected full-throttle speeds are:

25mph is probably a reasonable "don't exceed" speed for the bike loaded, so gear 7,8 wouldn't be used. Here's the bike, as it was a few revisions ago:

It'll have a small, clamp-on Topeak rear rack and sliding bag, and on the front will be a wheelable backpack. I'll also have some style of triangle bag for quick grabs like raingear and snacks.

[ncmired]

The only noice comparison I've come across is within the Electrify Bike video above, at the 5 minute mark. Not a great test, as the motors are in a room, on a hard bench, and not loaded, and is between the BBS02, BBSHD, and the Photon. On my builds, the BBS02 motors are indeed noisier than the BBSHD - a high whining sound at full throttle.

[Retrorockit]

I look forward to seeing how it turns out. That looks like touring bike fork with those rack mounting lugs on it. I agree 25mph would be plenty fast on that one.

[ncmired]

Related to motor construction and cooling, here's a vintage Luna teardown and comparison of the BBSHD and I think, the first CYC chain-drive mid-motor prototype. There's a fair amount of motor technology discussion:

CYC has learned some things, so it's probably not fair (for good or bad) to infer the Photon gizzards based on this video. As stts said - we need a Photon teardown. And some real-world, real-owner, varied use case testing.

[73Eldo]

When are we supposed to see these things actually hit the streets? Even if they are not out performing the BBSHD they could find a market if they have actually done their research and made them fit more recent bikes. I'm guessing the BBS's were designed to fit bikes that were common in the Asian markets 10+ years ago which appear to be pretty closer to 1990's MTB's. The current 1x's, suspension, and wider tires are not good things when it comes to fitting a BBS and getting a good chain line.

[ncmired]

When are we supposed to see these things actually hit the streets? Even if they are not out performing the BBSHD they could find a market if they have actually done their research and made them fit more recent bikes. I'm guessing the BBS's were designed to fit bikes that were common in the Asian markets 10+ years ago which appear to be pretty closer to 1990's MTB's. The current 1x's, suspension, and wider tires are not good things when it comes to fitting a BBS and getting a good chain line.

With the 34T chainring at a potentially 47.3mm minimum chain line, the Photon should be a better fitment for some conversions, time and builds will tell. Of the two North American vendors I know of, I think Golden Motors has slipped out their initial early January projection by two months, while Electrify Bike is still touting the same early January shipping. My EB pre-order has not yet shipped. CYC Motor direct sales are estimating six weeks.

[pbreezy]

Thanks for the info! I’m really looking forward to the Photon. I might have to dive in if I have any money left over at tax time. Would you order direct if you were in my place (I.e. not having a preorder in currently?)

[Retrorockit]

Considering I've had zero issues with my BBSHD I'm not sure where the improvement is going to make itself known???

[pbreezy]

I just really really like the torque sensing on my M600 and I miss it when I ride the BBS. Also I look ridiculous commuting on my X2. Feel very overdressed with 160mm of travel in the bike lane.

[ncmired]

Weight, torque sensing, and heat management IMO are the tantalizing draws. I still feel it won't compare to the BBSHD, power-wise, and obviously can't compare longevity yet. But, we'll see if they really are in real-world cases. We'll also see what the Photon downsides are (besides the price), given time - sure did with the Tongsheng. Will Photon spare parts be as easy to find as they are with the BBS series? Waiting a year will tell us a lot, and would be the smarter thing to do.

At this time, if you want to add a lightweight, light-duty torque-sensing motor to the analog frame of your choice, the possibilities are very slim. And, for me, the Tonsheng drawbacks take it off the "party of two".

Want brute, reliable power in a condensed mid-drive analog bike package? BBSDHD with Luna's V2 controller.

Electrify Bike's first batch of Photon motors came in without the speed sensors, and they're giving the first rounders the choice of sans-sensor shipments to get started on, with the sensor shipped "later"..

[ncmired]

it's the other way around that's the shortfall ;-)

Just kidding - I know you know, and I also should have added lower tooth count chain line to the first paragraph draws. I get that torque sensing is not universally wanted. I want to try it out on at least one bike, and still think it would be less confusing to my guest riders. Just my dopey hobby.

[pbreezy]

It’s the shifting that gets me. I never really minded the BBS when I ran it on a single speed; just dial the assist number for desired top speed. Didn’t even use a throttle because I would just shuttle if I wanted to take a rest. Then I got the X2 and it would ease up when I did, so there was no learning curve for shifting. Now the BBS is on a geared bike and I have to think about how to shift without the motor ripping the cassette off the hub. I’m toying with adding a momentary switch in place of the front brake switch so I could use it like a clutch… But haven’t gotten around to the logistics yet.

[Retrorockit]

I built a guest bike with TSDZ2, no throttle, IGH to be as simple to ride as possible. I agree that I wouldn't dare hand my BBSHD bike to a novice. But then decided a throttle is actually a safety device in traffic. Rewired the whole damned thing and found out the display isn't programmed for a throttle and I need to custom build a programming cable to do that. Then the throttle only gives the power level pre-selected. All I've had to do after 3 years of actually riding my BBSHD is grease it, and add a torque arm to protect the BB shell.If I want more torque that's what the throttle is for. I built it in a small frame bike, added a banana seat so I could ride. It feels "different" but not really better. If I want to do more work then the low PAS setting works just fine. If I don't then I crank the power up.I wouldn't go out of my way to get Torque Sensing, and certainly noy give up the advantages of the BBSHD. Luna should make a TS retrofit for the BBSHD. Then you would have something.