Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

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wayover13   100 W

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Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by wayover13 » Jul 30 2018 11:00pm

Hi. I've got a friend who will be setting up an electric assist bike for his college-age grandson for around-town commuting. He bought the bike already. It's a bike sold by REI, the Electra Townie. What he's interested in is a fairly low-power (say, 250 watt) mid drive kit with torque sensing that he can readily adapt to this bike. My friend is quite competent in the realm of mechanics and electronics, though he's just now getting involved in the realm of electric assist for bikes. Can anyone offer some recommendations for the type of kit he's looking for? As for a battery, that will likely be taken care of: I plan to donate to him an older 48V 10 AH battery of mine that likely has a few bad cells; he'll be able to put together using bits and pieces of that something suitable for this project. TIA
Oops. Looks like maybe I should have posted this in E-Bike General Discussion. Request: can a mod please move it there for me?
Minimalist-assist advocate. Minimal assist means only enough to ease some of the physical strain the rider must output to propel the bike at or near more typical unassisted cycling speed. Such assist usually plays no role in increasing the bike's top speed, being brought into play mostly when facing challenging terrain (steep uphill grades) or weather conditions (strong headwinds). Assist may remain completely disengaged for large segments of any given ride.

wayover13   100 W

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by wayover13 » Aug 08 2018 2:49pm

Anyone have experience with the Tongsheng TSDZ2 Mid Drive kit (https://www.amazon.com/TSDZ-Version-Ton ... B01MYRB6Q6)? That's the one we're looking at. Looks like it could be readily adapted to this bike: https://www.rei.com/product/851140/elec ... ie-7d-bike. Bottom bracket shell width checks out fine, though a slight modification might be necessary to attach the rear part of the motor to the frame (seat stays start a lot further back than on a more standard bike frame). Input will be appreciated.
Minimalist-assist advocate. Minimal assist means only enough to ease some of the physical strain the rider must output to propel the bike at or near more typical unassisted cycling speed. Such assist usually plays no role in increasing the bike's top speed, being brought into play mostly when facing challenging terrain (steep uphill grades) or weather conditions (strong headwinds). Assist may remain completely disengaged for large segments of any given ride.

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wturber   100 kW

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by wturber » Aug 08 2018 9:10pm

I have zero experience with mid-drives so can't be of much help there. But I do wonder why your friend wants to limit the bike to 250 or 350 watts when 750 watts is legal in Wisconsin?
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

wayover13   100 W

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by wayover13 » Aug 08 2018 9:28pm

Thanks for your input, wturber. The bike will actually be located and used in the state of MI. I'm not sure what are the regulations there. But I'm pretty sure my friend's logic in prefering a lower-power assist has to do with the fact that he would like for his grandson to be more physically active. The grandson has a minor disability which causes him to be fairly sedentary and thus a bit overweight. My friend's idea is that if he can get him riding a bike, he'll get more exercise and into better health; the lower-powered the kit is the less reliant the grandson will tend to be on the bike's motor to get him where he will want to go.
Minimalist-assist advocate. Minimal assist means only enough to ease some of the physical strain the rider must output to propel the bike at or near more typical unassisted cycling speed. Such assist usually plays no role in increasing the bike's top speed, being brought into play mostly when facing challenging terrain (steep uphill grades) or weather conditions (strong headwinds). Assist may remain completely disengaged for large segments of any given ride.

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wturber   100 kW

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by wturber » Aug 08 2018 9:47pm

OK. I understand. The counterpoint would be that the easier and more flexible it is to use, the more likely it will get used and provide some benefit. if it is Class 3 /pedelec with no separate throttle, you'll have to do some physical work to make it go. I guess what would work best would depend on the person's individual psychology.

Michigan in on the three class system much like California. So he can go up to 750 watts and 28 mph if he wants.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

wayover13   100 W

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by wayover13 » Aug 15 2018 12:56pm

With the aim of wrapping up this discussion I should mention that I finally ran across this thread: viewtopic.php?f=28&t=79788&hilit=Tsdz2 . That's a pretty lengthy discussion of the very kit I asked about in my second contribution to the current thread. I guess I had forgotten that somehow google search is not indexing this site, so I thought, regarding this mid-drive kit, that the findings I'd gotten through my google searches were all that was out there. But searching the forum on the term TSDZ2, I've just now run across a previously-overlooked resource on the TSDZ2 Mid Drive kit.
Minimalist-assist advocate. Minimal assist means only enough to ease some of the physical strain the rider must output to propel the bike at or near more typical unassisted cycling speed. Such assist usually plays no role in increasing the bike's top speed, being brought into play mostly when facing challenging terrain (steep uphill grades) or weather conditions (strong headwinds). Assist may remain completely disengaged for large segments of any given ride.

docw009   10 kW

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by docw009 » Aug 15 2018 1:48pm

The TDSZ2 might be the only torque sensing mid drive kit that you can put on an arbitrary bike with the right BB width. You can get one that is pedal only, but it might be good to have a throttle.

I have one, still in the box that I bought in July to avoid the current tariffs, except now I think tariffs won't be implied to a single motor bought by an individual. I had better open it and test it.

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John and Cecil   1 kW

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by John and Cecil » Aug 15 2018 2:32pm

There is another torque sensing mid drive motor for traditional bike bb's other that the tsdz2. We have the tsdz2 and it is ok, however it does have some issues and defects. The biggest issue/defect is the gears do not mesh well and the nylon drive gear can be destroyed if you are not careful. Some people have gotten a few thousand miles out of one, others only a few dozen miles. Here is a link to the other (newer) motor discussion:

viewtopic.php?f=28&t=94220

The forum user Eyebyesickle is very knowledgeable with both the tsdz2 and lingbei motors so you might be able to ask him (and the other participants of the thread) their opinion on which would be best for you.

wayover13   100 W

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by wayover13 » Aug 15 2018 2:45pm

Well, I thought I was wrapping things up here, since no further comments had been made for quite some time. And now, some new input. Thanks for the additional information docw009 and John and Cecil, and especially for the link to an alternative kit.
Minimalist-assist advocate. Minimal assist means only enough to ease some of the physical strain the rider must output to propel the bike at or near more typical unassisted cycling speed. Such assist usually plays no role in increasing the bike's top speed, being brought into play mostly when facing challenging terrain (steep uphill grades) or weather conditions (strong headwinds). Assist may remain completely disengaged for large segments of any given ride.

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John and Cecil   1 kW

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Re: Recommendations wanted: mid-drive ca. 250w kit w/torque sensing

Post by John and Cecil » Aug 15 2018 2:57pm

No problem. I kind of like what they are saying about the Lingbei motor. It is light, powerful, and it sounds like it might be reliable and durable, plus it is not very expensive. If I had a "wayback machine" I think I would have went with that instead of the tsdz2. Good luck with whichever motor you choose.

ps - 25% tariffs on e bike motors are kicking in very soon (like a week or two) so you migt want to order something SOON!

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