PaulD's lightweight mid drive development

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ScooterMan101   10 MW

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Re: PaulD's lightweight mid drive development

Post by ScooterMan101 » Apr 19 2020 12:30am

I am only thinking about a 12 speed system because at the present time they are the only ones that have a cassette that works with the XD Driver , unless something in a 9 , 10 , or 11 speed cassette that is XD Driver compatible just became available ?

I would prefer a 9 speed system like I have now for lower cost's , and strength . I once broke a 10 speed chain just pulling a trailer on flat ground with a 55 pound dog on it , so I prefer a 9 speed system , until the 12 speed Eagle components lower in price or SunRace makes low price XD Driver compatible cassettes .

What speed chain's are working with narrow-wide chainrings ?



PaulD wrote:
Apr 14 2020 10:48pm
ScooterMan101 wrote:
Apr 11 2020 2:18pm
Your narrow-wide chainrings , are they 11 speed ( chain ) or 12 speed ( chain ) chainrings ?
Rumor has it that most narrow wide chainrings work with 12 speed chain, but shimano chains need to use a SRAM quick link. I use a Shimano 11-46 11 speed cassette, and it's enough range for me and it's a fraction of the price of 12 speed.
My first conversion ... Sold

viewtopic.php?f=3&t=71378&p=1077497&hil ... 1#p1077497

It's 2018 already, ( now 2019 ) lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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Re: PaulD's lightweight mid drive development

Post by PaulD » Apr 20 2020 5:20pm

ScooterMan101 wrote:
Apr 19 2020 12:30am
I am only thinking about a 12 speed system because at the present time they are the only ones that have a cassette that works with the XD Driver , unless something in a 9 , 10 , or 11 speed cassette that is XD Driver compatible just became available ?

I would prefer a 9 speed system like I have now for lower cost's , and strength . I once broke a 10 speed chain just pulling a trailer on flat ground with a 55 pound dog on it , so I prefer a 9 speed system , until the 12 speed Eagle components lower in price or SunRace makes low price XD Driver compatible cassettes .

What speed chain's are working with narrow-wide chainrings ?
I think XD came out on 11 speed. So, 11 and 12 speed cassettes would be available. The only real advantage of XD is being able to use 9 or 10 T cogs, which I don't recommend for ebikes anyways.

Intuitively 9 speed is stronger, but it doesn't seem to be the case in practice. I think chain tech has gotten better over the years. Good info here: https://cyclingtips.com/2019/12/the-bes ... cy-tested/
Chains can handle an insane amount of load in a straight line. It's the side loads that kill them, i.e. - shifting under load.

I can't see why narrow-wide chainrings wouldn't work with 7, 6, single speed chains. I've only used them on 8-11.

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Re: PaulD's lightweight mid drive development

Post by PaulD » Apr 20 2020 5:37pm

Joost5000 wrote:
Apr 17 2020 10:45am
Let’s say you reduce torque requirements in half or a quarter; high speed low torque. From a rider perspective the feel of a always having a small tailwind. How how light of a system can you get to. I would assume with such low torque requirements you can use lighter materials and a much smaller motor. Perhaps leverage printed plastic instead of steel/aluminum. Can you get the overall system weight down say by 40% with the lower requirements?
This might be possible. One of the heavier items is the torque sensing BB, so that's a hurdle, the motor could be about half the size. Perhaps there's a controller like a VESC that could shave weight.
Printed plastic has a lot of disadvantages, but when used in conjunction with metal in the right places, could be useful to shave some weight.

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Re: PaulD's lightweight mid drive development

Post by ScooterMan101 » Apr 21 2020 1:28am

The Advantage of an XD in regards to a mid-drive is that with an XD driver and cassette , the cassette will not chew up the splines of the XD freehub body ... because it does not have splines .
I have nearly destroyed a Sram/Shimano type of freehub body spline interface between the cassette and the splines .
And that is taking it easy, with slow starts ecxept for one or two and not going over 1.5kw and no more than 30 amps mostly 20 amps or less.

So the Goal is to get rid of that weak point , where the cassette digs into the ridge of the freehub body.

I do not even use the 11 tooth cog on a cassette on a mid-drive . For me it is 13 teeth lowest and that is rarely , I most often the 15 tooth one on the flat areas.

Chains I have heard have gotten better with the advent of e-bikes, somewhere I saw where the Sram Eagle had improvements , so another reason why I like it , except for the price .

Since I live around hills and Mountains, I prefer at least 9 cogs on the rear , I would go with 8 if it was 13t - 48t or 50 t

What sizes of Narrow - Wide Chainrings do you have available in a 104 BCD bolt pattern ?


PaulD wrote:
Apr 20 2020 5:20pm
I think XD came out on 11 speed. So, 11 and 12 speed cassettes would be available. The only real advantage of XD is being able to use 9 or 10 T cogs, which I don't recommend for ebikes anyways.

Intuitively 9 speed is stronger, but it doesn't seem to be the case in practice. I think chain tech has gotten better over the years. Good info here: https://cyclingtips.com/2019/12/the-bes ... cy-tested/
Chains can handle an insane amount of load in a straight line. It's the side loads that kill them, i.e. - shifting under load.

I can't see why narrow-wide chainrings wouldn't work with 7, 6, single speed chains. I've only used them on 8-11.
[/quote]
My first conversion ... Sold

viewtopic.php?f=3&t=71378&p=1077497&hil ... 1#p1077497

It's 2018 already, ( now 2019 ) lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

Nobreaks   10 µW

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Re: PaulD's lightweight mid drive development

Post by Nobreaks » Jun 01 2020 5:24am

Hi Paul and every one else hope everyone is ok.
Paul when are U looking at doing another production run.?
Unfortunately I missed the last one by couple of weeks shy of having the coin spare.

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Re: PaulD's lightweight mid drive development

Post by PaulD » Jun 01 2020 1:46pm

Hi Nobreaks,
It's TBD at the moment. I have a lot going on right now, but I'll try to post an update in the coming weeks. Thanks for your interest!

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Re: PaulD's lightweight mid drive development

Post by ScooterMan101 » Jun 04 2020 2:24am

A lot going on ? like a version that will accept a 15 s battery pack, or 18s battery pack , or even a 20s battery pack ?

A version that the controller can interface with a CA V 2.3 or CA V 3 ?


PaulD wrote:
Jun 01 2020 1:46pm
Hi Nobreaks,
It's TBD at the moment. I have a lot going on right now, but I'll try to post an update in the coming weeks. Thanks for your interest!
My first conversion ... Sold

viewtopic.php?f=3&t=71378&p=1077497&hil ... 1#p1077497

It's 2018 already, ( now 2019 ) lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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Re: PaulD's lightweight mid drive development

Post by neptronix » Jun 09 2020 4:18pm

I'd like to try one out on one of my bikes, if i could get a custom winding or custom gearing that'd do 80-100 rpm cadence on a 48v nominal battery, fitting a 68mm-73mm size bottom bracket.

I know that's a lot to ask considering you designed this for 36v, but 'it never hurts to ask' :)
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Re: PaulD's lightweight mid drive development

Post by Joost5000 » Jun 11 2020 12:14pm

The beauty of the system is it just silently sips watts as you pedal along. I have a midfat 29er Jones bike with 32 tooth gearing 11/34 cassette. I can comfortably pedal low 20s on pas assist 2 of 5. I can reach upper 20s on pas 5 or throttle. How fast are you looking to go?

It makes my mid fat bike a single do it all bike; though I still have my 3k watt rat bike to go 40+. It’s a bbshd with steel gear and ert controller. It’s loud and torque-ey the complete opposite what Paul has accomplished here. If there’s one problem with Paul’s setup, you don’t need to tweak it. Super quick install and no tuning or maintenance required.

The cyc motor seems to be stabilizing somewhat if your looking for more power. Though I believe the Q factor may not be what your looking for. Actually, I had no idea what that really was until I read this thread;).

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Re: PaulD's lightweight mid drive development

Post by Nobreaks » Jun 16 2020 6:30pm

So jello
Hopefully Paul has another production run before I stop holding out and buy a CYC gen 2

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Re: PaulD's lightweight mid drive development

Post by Joost5000 » Jun 17 2020 12:34am

Nobreaks wrote:
Jun 16 2020 6:30pm
So jello
Hopefully Paul has another production run before I stop holding out and buy a CYC gen 2
Paul nailed PAS and the fit and finish of the system. Every component of the system has been thoroughly thought through. Just holding the battery or spinning the custom freewheel can show the amount of detail that has went into this product. I had a few minor suggestions to the system. He already thought about them and had reasons why he went the route he did.

Cyc is pretty much the opposite engineering approach; cobble together a bunch of parts and package around a now respectable motor in a sleek looking package. For better or worse, cyc has appealed to the hot rod market It has somewhat an uphill battle sourcing the right components to deal with that kinda market. I believe they’ll get there as there is lots of enthusiasm around the platform. But be prepared to get your tools out. Full disclosure, I Just ordered one of these as well.

Revel is focused on a very specific problem/market and delivered. If you’re the type that still likes to pedal vs moto/moped; you can’t go wrong. I’ll ride this while I’m wrenching on the cyc.

No breaks, I followed this thread for a year before I purchased so I get your pain:).

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Re: PaulD's lightweight mid drive development

Post by lightrush » Jul 02 2020 12:54pm

Paul, my dude, my G310 is beginning to exhibit some unhealthy noise. I need your help! (by letting me buy one of your kits)

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Re: PaulD's lightweight mid drive development

Post by passuff » Sep 15 2020 3:13am

PaulD wrote:
Mar 15 2020 3:10pm
lightrush wrote:
Mar 14 2020 4:18pm
What new torque sensor?
I've been having good results with the Erider for the last 6 months, so we are going with it. Here it is with the new freewheel hub.
IMG_20200315_094502_copy_2024x1518.jpg
Sorry for crashing your thread. I have a cyc x1 gen 2 and have issues with the stock BB. Now I'm looking for alternatives which seem to be rare (proper torque sensing with freewheel). I searched your shop for the spider freewheel but couldn't find it. Do you not sell it separate?

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Re: PaulD's lightweight mid drive development

Post by Joost5000 » Sep 15 2020 9:01am

I have both the revel and cyc. There really isn’t an easy Way to interchange. I believe they are using the same torque sensor, but the Freewheel interface is entirely different format; different bolt patterns as well. You can’t even use the same Drive chainring as cyc uses a larger drive chain. I would go back to cyc; they are very responsive.

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Re: PaulD's lightweight mid drive development

Post by Joost5000 » Sep 15 2020 9:08am

Also keep in mind, revel is designed specifically for 36v; it is much lighter and It’s not designed for 52-72v. With the cyc, the chainring assembly alone weighs close to 1 lb.

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Re: PaulD's lightweight mid drive development

Post by PaulD » Sep 30 2020 5:42pm

Hi All,
It's been way too long since the last update. Kits have been sold out for a while now, and I have been too busy with other things to resolve some production issues and build more. There have been a mountain of set backs, and issues with 3rd party part compatibility and I feel like I don't have time to whack-a-mole all of them in a reasonable amount of time. So, I've decided to open source this project.

I've never really officially made a project of this scope open source, so I'm open to any suggestions on how to do it. I can put all of the CAD into a repository and wiring diagrams. Is Github a good idea? I have done zero research at this point.

One of the major compatibility issues that I haven't tackled yet is the ASI controller and the Erider torque sensor. Only relatively small percentage of users had issues, but I don't have a fix for it yet. I will post more on this later.

Anyway, I'll be assembling a batch of motors and mounting brackets and controller only (no torque sensor, freewheel, display, battery) if people are interested, please reply or PM me.

Thanks to all who supported this effort so far!
-Paul

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Re: PaulD's lightweight mid drive development

Post by neptronix » Sep 30 2020 6:23pm

I'm really sorry to hear this.

Github would be a good choice, but make sure you leave a link to here of course, lest it be lost in space, since people wouldn't just casually browse github and come across your works.

I'd love one of your motors but i won't be in any physical condition to work on ebikes for the next 6 months. Darn.
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Re: PaulD's lightweight mid drive development

Post by lightrush » Oct 01 2020 1:33am

Sorry to hear that, but the decision to open source this is a great one.

I'm currently running an Erider with a CA and a G310 hub. The Erider seems to coexist fine with the CA. I think to be useful we'd need the freewheel hardware for the Erider so we could mount it. Then we could tinker with the CA on how it handles the torque signal. We could hook up another controller if needed too. Without the freewheel however, we're limited to using the square taper freewheel that other kits use on a Thun with left-hand torque only. Also from my limited experience with a Sempu T2, 2x Sempu T4 and an Erider, the latter is significantly better than the Sempus. It's not perfect. Backwards rotation doesn't consistently disengage, but that's not a huge problem when using a CA and having a brake sensor.

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Re: PaulD's lightweight mid drive development

Post by HrKlev » Oct 01 2020 2:38am

The CYC pro kit has a torque sensor and a freewheel that plays fine together with a CA. Its available as a spare part on their webshop, for 100mm, 63mm and even BB92 bottom brackets. I think it is a erider with a modified flange. Its not as nice as PaulID's solution where the freewheel sits outside the BB, but it seems quite OK. I havent used it for a long time, so cant say anything about longivety. Im using it with a small midmounted hubmotor, but it should work with PaulID's motor/motormounts as well.
DIY lightweight mid drive with torque sensing build thread: viewtopic.php?f=6&t=107622

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