Manufacturers not promoting DIY middrives w/torque assist

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melodious   100 kW

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Manufacturers not promoting DIY middrives w/torque assist

Post by melodious » Aug 28 2017 12:12pm

:? Been here long enough and either browsed/read new posts of new products on the horizon so I can gauge where the tech is going. Batteries are predictably changing every 3-5 years, which might change with the gigafactory. Motors are actually progressing faster than I can keep up, and that's awesome :!: Controllers seem to have hit a wall, maybe limited by battery potential?

Anyways, the mid drive revolution that Bafang seems to have created has got me wondering. Why haven't they or other companies developed torque sensing mid drive motors for the DIY communuty :?: I'd imagine that it should be easily implemented into previous models and would make the torque pedal assist more intuitive vs. RPM pedal assist. Is it because the power rating of the these motors are greater than say the Bosch, Shimano, Yamaha, etc. motors and prevents a cyclist from accidentally "power torqueing" into uncontrolled wheelies :?: :mrgreen:
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fechter   100 GW

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Re: Manufacturers not promoting DIY middrives w/torque assis

Post by fechter » Aug 28 2017 1:19pm

I don't see any real reason a Bafang couldn't have a true torque sensor. It might need to be thicker to fit the sensor (not good) but seems like there should be some way to integrate it within the existing outline. For sure it would add some cost and they would need to re-do the firmware to make it work.

There are several other things they could do to improve them, like adding an Amp-hour measurement to the display. All the hardware needed for that is already there, it just needs some software changes.
"One test is worth a thousand opinions"

docw009   100 kW

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Re: Manufacturers not promoting DIY middrives w/torque assis

Post by docw009 » Aug 28 2017 4:12pm

I believe Bafang does have torque sense in their mid drives intended for OEM frames, and I believe you get torque sensing in the TDS mid drive DIY kit.

I took the opportunity to ride about dozen bikes at a local ebike demo this summer. Torque sensor on a commercial bike (Bosch/yamaha) didn't feel any better than the torque simulation PAS bikes I own. Quite satisfied with my BBS02's PAS too. I don't think I would ever upgrade to a new BBS just for a torque sensor if they became available.

Eventually, I suppose torque sensors will fit in with future automatic transmission ebikes. People who start off in the wrong gear and fall over on hills will love it.

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spinningmagnets   100 GW

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Re: Manufacturers not promoting DIY middrives w/torque assis

Post by spinningmagnets » Aug 28 2017 5:02pm

Most DIY kits that are added to a standard bicycle frame are typically "hackable", and also very simple in construction to keep their price low. When you look at countries around the world, there are a wide variety of power and speed limits, and the companies that make ebikes are trying to navigate all of these issues while trying to be more successful than the competition.

The vast majority of citizens who have just recently realized that ebikes exist, do not want to risk getting a citation from the police, or to have their expensive new ebike confiscated by the city government. So...this has divided the manufacturers into two camps...One camp that is occupied by the mainstream manufacturers who make built-in motors that have a proprietary mount (cannot be transferred to another frame), and are hard to hack. Many EU countries have a 16-MPH speed limit for the application of power, and a 250W power limit (Austria and Switzerland have a 500W power limit).

In this instance, if you are pedaling 30MPH and are stopped by the police? It is demonstrable that the bike cannot provide more than the factory-rated power and cannot provide that power at any speed above the legal limit. Meaning that: if you are traveling 30-MPH, it is because you were going downhill or you are a very strong bicyclist. You can still get a ticket for reckless riding, but your ebike will not be confiscated due to having 1,000W, or...because you were applying electric power at 30-MPH

Kits are different. Besides the obvious consideration that they are designed to be able to attach to a wide variety of common bicycle frames, and can easily be swapped from one frame to a completely different model. A kit manufacturer can claim that his kit is "for off-road only", but...when riding with it on the city streets, most police are still in a fuzzy state of awareness where they don't pay any attention as long as you are not riding in a way that endangers everyone around you.

Stealth ebikes in Australia started out making 3000W+ ebikes in Australia, where the legal power limit is 200W, so...up until recently, all of their products were for "off road only". (I have soldering irons that use more than 200W)

Bafang is a company that is trying to make inroads in both worlds. They make well-known kits, but...a couple years ago they also came out with their "Bafang Max" drive, with a proprietary mount (similar to Bosch and Yamaha), which can be hard-wired to meet the power/speed limits in various countries (meaning, not easy to re-program/hot-rod).

https://media.licdn.com/mpr/mpr/shrinkn ... NWZhOA.jpg

Torque-assist pedaling is one of those features that not only cost more than a speed-sensing PAS, it is also desirable for the expensive factory turn-key ebikes with proprietary drives. Large and powerful mainstream ebike manufacturers are applying pressure to keep several existing differences between factory drives and kits. There are kits with torque-sensing PAS, but they are not common...

Steu851   1 mW

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Re: Manufacturers not promoting DIY middrives w/torque assis

Post by Steu851 » Aug 29 2017 1:11am

TSDZ2 has torque sensor and is cheaper than bbs01

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melodious   100 kW

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Re: Manufacturers not promoting DIY middrives w/torque assis

Post by melodious » Aug 29 2017 3:25am

Steu851 wrote:TSDZ2 has torque sensor and is cheaper than bbs01

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Ya. I'm aware of that product. But it's lacking in power for my Ebike quiver. Not unless folks are pushing more volts & amps through it? Is that 36v motor controller limiting the available voltage input? Can I run it with a 50v+ battery without having the controller's capacitors blow? And how many amps can that controller really take? Guess I'll have to read up on what folks are doing to it. :wink:

viewtopic.php?f=28&t=79788 (42 page thread as of 08/29/17)

Edit: read a few pages (5-6, and a few near the end) and got this...
-The "36v" 10s caps won't allow overvolting to "48v" 13-14s and shuts down (apparently it doesn't blow the caps)
-18amp max limit. To go above this threshold is risking the primary gear shaft to break.
-there are 3-4 more companies that offer a torque assist mid drive than the TSDZ2, and apparently they all are as power anemic as this one.
-on the positive side, the torque assist gives a more natural ride feel vs. the 350w BBS1 bafang drive.
Surly Ogre rigid 29er, rear 10T MAC @ 50V 25AH & 40A: 30mph road/gravel/hill machine
42" dual diagonal Eskateboard @6s & 90mm wheels
Next: eMTB @10-12s & 8"-12" pneumatic wheels; Got Strapped? d-(',')z

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Re: Manufacturers not promoting DIY middrives w/torque assis

Post by RTIII » Aug 29 2017 10:33am

Torque measuring assistance in general, and the TSDZ2 in particular, is for people who don't want a moped that claims it's a bicycle. Seems to me that those who sneer at the "anemic power" of such systems are trapped in their own ignorance and perhaps dogma.

I love my 48v 15A rated Tongsheng TSDZ2. It doesn't require a throttle, or brake cut out switches, and provides a very natural riding feel. Smooth, quiet, powerful. I can cruise up steep hills I wouldn't want to WALK up at over 10 MPH, and get to 25 MPH very easily. I blow past my pedal-only friends when we ride together; there's nothing "anemic" about it. In fact, it's strong enough to be known to strip its gearing if the rider habitually puts too heavy a load at too low an RPM. (It's intended to be used in geared systems, so use your gears!)

Furthermore, I have battery range that the BBS folks could only dream of. I've got a 12.something AH battery that has a range of over 90 miles on a single charge, WAY more than I'd ever actually need, and the battery will still be giving me lots of range years from now when its capacity is greatly diminished by age.

I recommend that before you diss something like the TSDZ2, at least become familiar enough to know what you're talking about; they're a fine product that works well, provides great power, gives a more natural feel, has superb range, and doesn't turn your cycling experience into a moped you can pedal home when you run the battery flat. SOME of us love all that and aren't interested in megawatt systems. I guess it's a matter of sophistication over raw brawn.

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robocam   10 kW

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Re: Manufacturers not promoting DIY middrives w/torque assis

Post by robocam » Aug 29 2017 5:38pm

If Bafang would introduce their next BBSHD-like model with a torque sensor, I would buy it in a heartbeat. Why didn't they introduce the Ultra in the same format as their DIY kits?

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Matador   100 kW

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Re: Manufacturers not promoting DIY middrives w/torque assis

Post by Matador » Aug 29 2017 11:41pm

robocam wrote:If Bafang would introduce their next BBSHD-like model with a torque sensor, I would buy it in a heartbeat. Why didn't they introduce the Ultra in the same format as their DIY kits?
Also if it was possible to use the Bafang controller and original display at higher voltages (ex 72V),that'd be crazy !
True that Bafang need a reliable watt meter tooé
Torque sensor would be absolutely awesome...

But to me, the absolute top of the top would be a Bafang mid-drive that would integrate a gearbox like the `Pinion`gearbox !
No more chainrings to destroy...


Why haven't anybody thought about that. A combined mid-drive + gearbox...
Matador

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