Mid-Drive Build - comments and recommendations welcome

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
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FlightService
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Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Nov 15, 2017 1:01 pm

As a good friend always said "Either do it or shut up" So here we go.

I am looking at a mid-drive build. Probably start after the first of the year so I will be picking up pieces between now and then.

I am a first time builder but I do not want a hub drive. I do not like the balance being that out of whack. Also, I am a mechanical engineer so I figure out how to break most things in the most spectacular way.

The bike I have chosen, due to cost, fit, and availability is the Specialized Sirrus Sport Disc. I am 6'5" and this thing fits me and was a good deal ($150 used local) I have fun riding it.

The intent is to use this bike as a commuter. I live in the DC metro area on the NOVA side and there are plenty of trails. I have a 10 mile commute to work that no matter how I cut it is an hour. By my calculations, I can match this on an e-bike easy peasy. (And by calculations I mean checking 3 different bike route calculators and talking to 2 riders that commute to the area on the same route I would be taking).

I originally was looking at the Bafang BBSHD, but I am not a small guy. I didn't want something that would be stressing itself for the uphill climbs it would be looking at. So it would work but from all the research it would be a marginal choice in the application.

That leads me to the cyclone 3000W kit from Luna. Yes I know I do not need 3000w. Doesn't mean I have to spec the system for 3000W or gear it to need it. It is also cheaper than a BBSHD and lends to the steampunk look I am going for on the bike.

So, that being understood, my design requirements are cheap and lasting. I know I am giving up lightweight and quick acquisition of parts but I am 250 lbs and am patient.

I was thinking of going with Maxxis Hookworm tires (open to suggestions). Have the triple chain ring, shift sensors and cadence sensor for the cyclone.

As said in the topic - any advice and recommendations are welcome.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by fechter » Nov 15, 2017 3:11 pm

How fast do you think you want to go?

Feeding a 3kW motor you need to consider the battery requirements. A BBSHD might be more expensive, but you can probably get away with a smaller, less expensive battery.

I have a BBSHD and I've been real happy with it. The Cyclone will certainly have more power, be louder, and require a bit more maintenance. It also gives you a lot of gearing options. At 52v, 30A, the BBSHD goes about 28mph on my fat bike.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Nov 15, 2017 4:14 pm

Hummm, how fast do I want to go....that is a question that will take a lifetime of contemplation and the world's total of financial, natural, and human capital resources to answer.

I want this bike to be able to run 25-30 with me (18-23 is acceptable), all my gear and uphill a 1% grade. I would estimate total weight for everything is in the 300-310 range. (Me, work backpack with laptop, lunch ect. bike, motor and batteries)

It has to run 22 miles trip. So based on calculations and multiple threads I can expect to loose 20% of the battery over a reasonable section of its life so I added half of the range again.

So a target full charge loaded range of 33 miles. So if I lose my 80% I am still at 26 miles range.

Don't get me wrong I like the BBSHD, it is just hard to ignore double the power for 2/3rds the price. Please correct me if I am wrong on this one, it is better to run a 3000W motor at 1500W than a 1500W motor at 1500W.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by fechter » Nov 15, 2017 8:27 pm

A larger motor run a partial power might have slightly higher losses than a smaller one running closer to it's potential. That's everything else being equal. I suspect the BBSHD overall efficiency might be a little better than the cyclone, but I don't know anybody who has actually measured it.

For sure having some extra power on tap is handy at times and you won't have motor heating issues.

A 1% grade is basically flat, so you should have no problem. Even a 10% grade would be realistic if geared down.

The cyclone might require more frequent service on the reduction gearing.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Nov 16, 2017 6:47 am

I noticed the planetary gear set of the Cyclone was nylon and a replacement part made of sintered PM is available

I was going to clean and upgrade the grease before the first run

I have done some searching but can't find many specs on the motor of the cyclone. (Poles, winding etc). That is frustrating
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Re: Mid-Drive Build - comments and recommendations welcome

Post by progrock » Nov 16, 2017 6:59 am

I'm building a cyclone 3000w right now, almost complete. Though I ordered mine from sickbikeparts.com, not Luna. Luna's does come with a nicer stock mount though, but it can also be bought from cyclone in taiwan, and in fact the mount got to me in close to a week, pretty damn fast.

Anyway, to power the thing, I'm using the new Sanyo 20700A cells, 30A continuous each, and 3100mAh. Since the majority of my rides will be relatively short distance, my main pack is just a 20s2p. But gonna build a second pack for longer rides. Anyway, the 20s2p pack is actually competely capable of piushing out 3000W+, and I'm getting the cells from Bosch 18v 6.3ah batteries. Getting to of those battery packs, each with 10 Sanyo 20700A;s in them, for $105 shipped off ebay (and they are a relatively new product from bosch, so they are very new batteries in these... nothing like sourcing from old laptop batteries). On top of that, they come with copper (instead of nickel, or worse nickel plated steel) connecting the cells together, laser welded... and are held in Bosch's "Coolpack 2.0"... which is a plastic holder specifically designed to keep the batteries cool. On top of all that, my 20s2p is literally 4 of the 18v batteries in series (of course beefing up the copper to handle 4 times the amps). But not only am I getting really good quality, high amp, new cells... but benefiting from their current structure... all for $210 total. A pretty damn sweet deal IMO. Plus would be easy enough to build 2 of these if you wanted twice the capacity.

I think both the cyclone and my batteries are some of the best deals currently available, and def recommend them. Also, installing a cyclone is MUCH easier than Luna makes it sound like.

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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Nov 16, 2017 7:53 am

20S2P!

Holy Voltage Batman! That sounds like a speed demon. I like. Do you have a link to your build? Love to study it. The BoschGBA18V63 CORE 18V Li-Ion 6.3 Ah FatPack Battery seems like a nice package. Are you disassembling them or did you build a holder? Pics man, PICS!!!!

Have you seen the Milwaukee 18V 9aH packs? Seems 6 of those would get you a very nice 54V and 18aH

Just for reliability I wouldn't want to push the controller near its stock 72V capacity. I would do a 54v @ 12.6aH to start with. 6 Bosch packs with 3 in series then to 2 in parallel. I haven't had my coffee so I am not going to do the actual math to get a total pack arangement. That would be a $315 pack. Hard to beat.

I like the 20700/21700 cells. I like scrounging for them. I saw a youtuber take a bunch of dewalt packs and place the normal cradles in the triangle of his frame. From thirty feet it looked like a W Triple 1920's board tracker setup.

I went through all of Lunas videos and links. I agree it doesn't seem as arduous as they make it out to be. The two things I think would be the least bit concerning is proper mounting for chain alignment and routing of the wires to prevent rubbing or water issues. I get why they do it though. You don't want someone that has always had their LBS build their bikes for them to attempt a conversion like that. If you can't put together an IKEA dresser, best not try something without factory support first.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by progrock » Nov 18, 2017 2:49 am

Pics will be coming soon, once I finally piece everything together... keep getting side tracked either with another project, or waiting for some other small part (this time it was some large washers.... which arrived today... hoping they do what I need, but haven't tried yet). For the 20s2p pack I'm utilizing as much as I can of the original battery packs from bosch (considering it's already got Copper welded to them, which ain't easy... and they are in a special plastic holder that's specifically engineered to keep them cool). It was actually totally accidental... originally planned to build a 14s or so, and then gradually decided to go up to 20s (almost 24s.... but that's on the side right now, may not even be a good idea in any sense or form). Anyway, it literally took a few days before I suddenly realized that I didn't need to take the batteries out and rearrange and re-weld them... they were setup perfectly for a 20s2p pack already. BTW, one of my primary goals is to keep the bike as light as possible for normal everyday rides. I realized most of the rides I'll be using it for are under 5 miles round trip, AND more importantly, I live in a building with no elevator (luckily only 1 floor up).... but I bought a used commercial ebike a while ago (got a VERY good deal on it)... but literally only used it once because its such a HUGE pain in the ass to carry up and down the stairs (its a solid, well built bike, with an elevator or a bike room on the ground floor I would have no complaints). So this bike has to be easy enough to carry up and down the stairs to be worth it.... and originally expecting to need close to 100 batteries to get anything close to 3k W... when I found these 30 A batteries, I celebrated. I still need to beef up the copper (especially between batteries) to allow 4 times their usual amps to go through them.... but that shouldn't be too hard (just need to come to a decision on what's the cleanest way to accomplish this). Build should be complete within the next 2 weeks... and will try to take photos of the important parts.

Anyway, when I build another pack (for longer rides)... probably 20s3p, maybe 20s4p... I plan to 3D print my own holders that I will design (seeing how most are designed for 18650)... and I have an interesting idea of utilizing nickel welded to the batteries with a copper plate screwed down on top (using knurled insert nuts that will be inside the plastic holders I make, between the batteries). That way I should have a very clean design, capable of serious amps, while not needing to be able to weld copper to the batteries myself.. plus everything should be held together pretty damn tight, ready to handle some serious abuse. When I get to this, will be posting a full build log, and will be providing the battery templates in both 3D printable files, as well as the original 3D models that will be setup parametric, so anyone can edit them very easily for different battery sizes and number of batteries.

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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Nov 30, 2017 12:11 pm

So after reviewing the new Bosche packs, I think that would be the way to go. I can get a 54V, 12.6ah for $315. (3s2p set up of the Bosch packs for an actual 15s4p overall) So being they are Sanyo 20700A they are rated at 30amps. So I can do a safe peak of 54V @ 120Amps for 6480 W of power!

Holy crap that is more than I will need. I think the 20700B would work better given I need more range than amps, but the price is hard to argue with (~$5 per cell, in a protective case already laser welded with copper).

So controller must behave itself, I won't have to worry about overdrawing amps from the batteries to the controller, that's for sure.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by John in CR » Nov 30, 2017 10:16 pm

Hubmotors rule for commuters. Weight balance only matters if you plan to go airborne or when you carry it, otherwise a rear hubbie can feel as light and nimble as a pedal bike. To me the prime requirement for commuting is reliability, and I demand absolute reliability from my bikes, and a mid-drive can't do that.

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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Dec 01, 2017 7:12 am

John in CR wrote:
Nov 30, 2017 10:16 pm
Hubmotors rule for commuters. The prime requirement for commuting is reliability, and I demand absolute reliability from my bikes, and a mid-drive can't do that.
What is your recommendation?
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Re: Mid-Drive Build - comments and recommendations welcome

Post by ScooterMan101 » Dec 02, 2017 2:07 am

I have two hub motors and do not feel any un balance, but I ride on the street 99 % of the time.
Q100c CST 201 Rpm wind, and the Mac 6 T .
I put the batteries in the middle of the bike , inside the main frame.

You Say you want to reach speeds of up to 25-30 mph, but would would be happy with mostly going 18-23 mph.
And
That you have a Sirrus Sport Disc Frame which is a light weight mostly road bike.

In order to reach speeds of 25-30 mph you will have to use a hub motor with the same power as the Rear Mac motor,
at around 48 but better yet 52 volt battery pack.

The Sirrus Sport would be better off with one of the lighter weight hub motors like the 2.1 kg Q100 / Q100c CST or the slightly heaver Q 128 or the 2.9 kg MXUS 08,
But you will not reach that speed with those motors, they are best at up to 20-21 mph max.
So that leaves the Mac Motor.
in the past it was the heaver motors that gave the performance/speed like the heavy Direct Drive Hub motors,
However
I would not use a motor heavier than the Mac on a Sirrus Frame. With a DD hub motor you want a very stout MTB frame, with suspension .

With only a 1% grade you can get the faster winds of Mac , like the 8 T or even faster the 6 T , buy many here would advise the 8 T when lacing the hub to a 700c wheel.

With Grades up to 4- 5 % Rear hub motors have advantages. Steeper than that you would want to use a mid-drive.







FlightService wrote:
Dec 01, 2017 7:12 am
John in CR wrote:
Nov 30, 2017 10:16 pm
Hubmotors rule for commuters. The prime requirement for commuting is reliability, and I demand absolute reliability from my bikes, and a mid-drive can't do that.
What is your recommendation?

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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Dec 02, 2017 3:11 pm

I like the 54V Bosch set up discussed earlier. I have read (please correct me if I am wrong) that a 12t MAC will give me what I want of a 25 mph with a 700c motor. I am not after a top speed bike. I want something that will hammer out mile after mile of stress-free riding. That is why I was looking at the cyclone. The setup I want would only be pumping about 2200w through a 3000w system. I will track down a local rear hub build and ride it concerning the balance. I can be convinced to change my mind from the mid drive kit.

The Sirrus is a 2005 model. Seems to be more stout than the later reboot.

Where is a decent place to purchase a MAC? My Google Foo is leading me to $1000 resellers, the OEM and dead links.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by Chalo » Dec 02, 2017 4:11 pm

At the pedicab maker I work for, we use cyclone 3000W motors for our e-assist units. But we run them at less than 1000W. The motors themselves have proven to be quite reliable (the only problems have been external freewheels and a few Hall sensors), but they're hard on chains and mounting brackets.

The Cyclone 3000W is a tinker's system. If you like wrenching on it, getting your head around it, and making some custom parts, you'll like the Cyclone. But if not, you'll be happier with BBSHD or BBS02, or a geared hub motor. In my opinion, even 2kW is too much power for the Sirrus, and will give you more hassle in the form of added maintenance and breakdowns than the excess power is worth. You'd be surprised how much performance 1000W nominal will get you, when it's coupled with an efficient, well maintained bike.

EM3EV has MAC motor kits. He's a reputable longtime seller and a native English speaker. https://em3ev.com/shop/?prod_cat_=hub-motor-kits-motors
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Dec 02, 2017 4:55 pm

Chalo: Thanks for the info. The 2000W is peak not nominal Nominal from what I can calculate is about 700w. I have one very nice 6% grade right off the bat that runs for about 1/2 mile. Then it tapers to a 3% grade for a little more than a 1/2 mile. That is 100 ft of the 300 ft of elevation rise over the 10-mile run.

EM3EV is a source. I have found them online and looked at the store. “The bitterness of poor quality remains long after the sweetness of low price is forgotten” – Benjamin Franklin, the problem is EM3EV is pricing themselves out of me doing business with them. I am doing this on the cheap. Right now the bitterness of not being able to assemble the kit is remaining because the sweetness of low price doesn't exist, at least not where the MAC is concerned. EM3EV is coming in 20% more expensive with the MAC than a comparable optioned Cyclone kit.

The guys have a great reputation, and for those that can afford them, great! They are obviously doing something right. I am just not one of those people that have that luxury.

Do you have any other MAC distributors that would be more price friendly?
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Re: Mid-Drive Build - comments and recommendations welcome

Post by ScooterMan101 » Dec 02, 2017 6:50 pm

Now that you are being more informative about the steepness of grades you will be going up ...
The Q100/Q100c /MXUS 08 and even the Q128 I would , not recommend .
If you did not need it commute , and only rode sometimes on the weekend perhaps the Q128 at max power , but for a commuter The Mac or a Mid-drive would be best.
Now since it is a commuter and will be using it more than for recreation/exercise the Mac is less maintenance from all I have read about the available mid-drives.
( there are some mid-drives now in development that might change that but with one of them you will then have an added cost of E-Bike Specific Frame, Long Travel Fork, Long Travel Rear Shock , it has the Cyclone motor mounted on the Swing Arm so needs a custom made swing arm)

A Mac 10 T wind would work fine remember you have a Sirrus so you do not want too much torque on those skinny dropouts , even if it is a 2005. Remember to buy a Torque arm or Two.

Allot of people have sticker shock when it comes to electric bikes. but what most do not think about is the savings on gas ...money not spent on gas .
For Example : I can go for a short ride on my Motorcycle , just 2 hours or less, at 40 + MPG, and come back and spend
$ 8-10 dollars for gas. $ 12-16 for longer rides. can go for a 1.5 -2 hour ride on the e-bike and spend less than % 0.10 , that is less than 10 cents to recharge the batteries.
now add that up for every day you will take your bike to work,

post back here the figure / the dollar amount not spent on gas.

A while ago I saw a place that sold the Mac Rear Hub motor, but forgot where , because the cost was only about 12-or so percent less. Not worth it on a $ 300 motor, and they did not sell the controller/torque arm/Cycle Analyst, so with Em3ev, you get matching controller and Cycle Analyst for a well tested set of components . ( less maintenance so less cost in the long run )
And they have the second best after sale customer service in the industry , Grin Technologies in Vancouver B.C. being Tops.

To lower cost you could order a smaller battery like 8 -9 amp hours worth and a second cheep charger to keep at work.


FlightService wrote:
Dec 02, 2017 4:55 pm
Chalo: Thanks for the info. The 2000W is peak not nominal Nominal from what I can calculate is about 700w. I have one very nice 6% grade right off the bat that runs for about 1/2 mile. Then it tapers to a 3% grade for a little more than a 1/2 mile. That is 100 ft of the 300 ft of elevation rise over the 10-mile run.

EM3EV is a source. I have found them online and looked at the store. Right now the bitterness of not being able to assemble the kit is remaining because the sweetness of low price doesn't exist, at least not where the MAC is concerned. EM3EV is coming in 20% more expensive with the MAC than a comparable optioned Cyclone kit.


Do you have any other MAC distributors that would be more price friendly?
Last edited by ScooterMan101 on Dec 02, 2017 7:27 pm, edited 2 times in total.

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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Dec 02, 2017 7:22 pm

My job pays my transit pass. So this has a negative cost savings. The reason behind it is to bring a little time back to myself. Being in the DC metro area my 8.9 Mile bus commute is 55-75 minutes. I can easily chop that down with our local bike trails.

As far as costs power equals dollars and how fast do you want to go? My problem comes in with a 3000 W cyclone kit at $350 versus a 1000 W Mac hub options similarly at $450.

And from what I can tell that is all going in the profit margin for the bike shop. Which is fine I hope they make all the money they can. I just can’t budget for a negative return that way. Not when it comes to power or compared to having my Transit paid for. So either I find a different vendor for a Mac hub or I stick with the mid drive cyclone build
Last edited by FlightService on Dec 03, 2017 10:28 pm, edited 1 time in total.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by ScooterMan101 » Dec 02, 2017 7:33 pm

Did not know about you job paying for a Monthly Bus Pass.

Can you take the bus part of the way and ride the other ? Most buses have bike racks,

If you can do that then the lightest weight option is best, you could cut out that 6 % 1/2 mile section or even the other 1/2 mile that is 3% as well and cut down on travel time by riding most of the other miles.

The Cyclone might just be best for you then, I have not bought one because there is so much I would have to improve myself like the Mounting Brackets, Straps, better Chain Tensioners , etc. Machinists are expensive where I live.

I want my next conversion to be easier to do. have you looked at the TSDZ 02 ? , there is a 48 volt / 52 volt version with throttle being sold .

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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Dec 03, 2017 1:02 pm

That is a nice unit but again, more money for less power, and putting the bus in the loop kills the time savings due to schedule.

Looks like the cyclone is the right choice. Especially if pedicabs are using them at a reduced rating.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by John in CR » Dec 03, 2017 8:59 pm

FlightService wrote:
Dec 01, 2017 7:12 am
John in CR wrote:
Nov 30, 2017 10:16 pm
Hubmotors rule for commuters. The prime requirement for commuting is reliability, and I demand absolute reliability from my bikes, and a mid-drive can't do that.
What is your recommendation?
I stick to extreme performance ebikes where pedals are pretty much just a place to put your feet. That's because the law here is great in that a motor greater than 49cc or 5,000 watt (and police don't even know about the 5kw limit for electrics, which is vague anyway) makes a bike a motor vehicle requiring plates, inspection, taxes, etc. Plus I need highway speeds and the ability to climb very steep hills with a big load.

You mentioned your height, which will come into play regarding aerodynamics, though at 30mph or less it's not terribly significant like it is at higher speeds. You didn't mention your weight though, and 6'5" it could be drastically different than the smaller cyclist types on the forum. The all up load (you and ebike) is a major factor on every takeoff and every incline, and even at modest 25-30mph speeds weight info is needed to make solid recommendations. Another big factor to me is road quality. Hardtails are great on smooth roads, but with all the added weight and greater speeds of an ebike they can be brutal on buppy roads.

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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Dec 03, 2017 10:22 pm

6'5" 250lbs and the roads are decent with a few step hills as mentioned.

I like where your at on the extreme performance. I would love to find a generation old down hill bike and go to town. Maybe next build.

With the calculations I came up with I would have a peak available of 2400watts from the motor with a nominal needed of 700 (with human power including) for flat top speed use.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Dec 04, 2017 9:36 am

Maybe a Leaf 1500w motor is the solution...

https://endless-sphere.com/forums/viewtopic.php?t=66489
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Re: Mid-Drive Build - comments and recommendations welcome

Post by elementary » Dec 04, 2017 11:15 am

25 - 30 mph commute, 39 mile round trip with a grade? IMHO, its all about battery. I have cyclones, bbs 750, bbs HD and hub motors. for sure they all of the eat much more battery at speeds over 15mph and going up hill, and based rides with other ebikes... the bbs 750 with PAS at 14 mph average using 1 or 2 setting on flat ground and no higher than 4 on grades is the long distance king. Over 15 aerodynamics is a factor as is weight, tire type etc. maybe Consider the bbs750 with quick connect battery and carry a backup pack... 2 hobby king 6 cell packs in series (12s) is great for get home power... sure beats pedaling a 60 pound ebike

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FlightService
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Re: Mid-Drive Build - comments and recommendations welcome

Post by FlightService » Dec 04, 2017 2:00 pm

elementary wrote:
Dec 04, 2017 11:15 am
its all about battery.
I was looking at the NCR20700A that is found in the Bosch 18V 6.3 and Dewalt 20V 6.0 packs. I was going to run 3 packs series and 2 parallel as that would give me a 15s4p set up. The NCR20700B would be a better cell but you can pick up the Bosch/Dewalt packs for ~$50-~$60 Which gives a cell cost of $5-$6. Beats the fire out of $10 and a nice holder to boot.
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Re: Mid-Drive Build - comments and recommendations welcome

Post by markz » Dec 04, 2017 9:07 pm

You didn't mention your weight though, and 6'5"
Average lean weight would be low 200's then 300 is a bit of a beer belly, mid 3's on up its noticable belly.

Not sure what I was going to mention, just that with more weight you use up more Wh/distance and need more Ah in the battery.

I've been playing around with Justins ebike motor simulator, trying to get a clearer understanding of my setup and my battery.

My weight 375-400lbs
My motor mxus 3kw direct drive 3T
My controller is hksunwin
My battery is 62V 12Ah
My bike Townie Electra cruisier

What I notice is for every 62V 6Ah 10S4P brick I can do 8 or 9 km, so my total range is 18km or about 11 miles. If I go full throttle or there is a hill, that range is drastically reduced. So I try my best to speed up when hills come, and pedal abit on take offs.

Plan for more capacity (Ah) in the battery if you are heavy, or if you got hills, or lots of stop n go traffic.

I am trying to remember what my conhismotor 1kw was getting, it must have been a 5T maybe 4T, but I was using 36V which netted me less speed, but achieved more Ah in the pack on a set number of 18650 battery cans.

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