Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

[neptronix]

I've got a 'reverse components' 10mm angle spacer on order:

The suspension fork's 'seat' is about 7mm tall so this single big spacer should have enough metal hugging it to be solid.
Fingers crossed that it fits the current headset..

The next 2 days are gonna be over 40 degrees here in Utah.. so i'm going to take to the garage and start work on the seat rail while i wait on various parts to arrive.

 

[Bullfrog]

Neppy....just a couple tid bits you may already know about and have already considered but the Suntour XCR comes in a 24" version and my be worth looking into. Surly has some gears/cogs that are similar to what you posted and may work for you. Also, I use crank arms off of a unicycle...purchased from Unicycle.com. It gives me all kinds of options for extreme lengths both short and long, just in case you decide to go with different crank arms.

Motors...I just ordered a Schwinn Shuffle (Kick Bike) and I am following your build to see what you end up choosing for a motor. Doing some preliminary research for my Shuffle, I read that the G310 has some issues with flinging the magnets off according to Grin Tech...it is an inrunner. I am considering the Shangyi and the Ezee since they are outrunners they shouldn't have the magnet flinging issue. It looks like they are the only 100mm OLD "front" geared hub motors that are commonly available that might work for me. The Shuffle has 100mm dropouts both front and rear and I want to go with a geared hub so when I give the Shuffle a "Kick", I don't get the drag/cogging from a DD motor. The Shuffle has a 26" front and 20" rear wheels and I plan to mount the motor in the 20" rear wheel.

Standing by to see which motor you go with .

 

[neptronix]

Howdy and thanks for chiming in.

24" is much too tall and will create a big lift in the frontend.. i already have a suitable 20" fork.
My ideal crank arm length for my long legs is 175mm but i am making 170mm work. It is already sort of a compromise.

I have a G310 lying around and magnets flinging off is not a problem because i don't need to push it beyond 350rpm thanks to the mid drive. I see how that's a problem in a 20" wheel though.
The issue with the G310 is that it uses 0.35mm laminations and peaks at ~84% efficiency.. whereas other motors in it's size/weight class could hit 88-90% efficiency.. i'd prefer that.. and have at least one motor in mind ( keyde ) already.

If i was building a kick bike, i'd go with a very small DD because the drag on a small DD is so tiny.. it almost disappears. The efficiency would be high but weight would not be optimal. A geared motor in a 20" wheel has extra gear friction under power though so this eats at your efficiency.. unless a geared motor has been specifically designed for 20" use ( has a lower reduction ratio ), you can expect pretty poor efficiency.. i experienced this with my 20" geared eZee motor.. it was in the upper 70% efficiency wise.. it sucked!

 

[neptronix]

Here's where the project stands..

The angle spacer crown race does not fit the lower headset bearing because the angle of taper is not the same. So that's a bummer..
Everything else? i don't have time to work on it, and i can never get the garage warm enough to tolerate it.. so this thread is frozen for a bit.

Meanwhile, i've been ULTRA busy inventing a new web programming paradigm and testing it to prove it is the superior. Once that is sorted, i'm building an all in one tool for managing tasks, clients, invoices, and tracking time.. which has huge commercial potential. In addition to that, my day job of doing IT, web development, and server administration.

I have been so busy that i have no time for myself for another month. Wild!!

 

[HrKlev]

Have you ever considered mounting one of those small kickbike dd hub motors as mid drive? Just shave off the wheel-part and it should be quite small.

 

[neptronix]

That was my first idea.. but i looked at tons of spec sheets on those and never found one that exceeded 85% efficiency peak :/

Because the mid drive will be spinning between 160-240 rpm while i pedal, a small, efficiency oriented DD would be killer.

 

[HrKlev]

Ah, I see. Will be interesting to see what you come up with. I have a bike running a Aikeema 75sx, and ordered a Bafang G370 for the other bike. Efficiency on the Bafang is quite poor, and I have no idea about the Aikeema. They are smooth and light, which was important for me. Alway looking for better solutions, so will be following this thread closely

 

[neptronix]

I've never seen an Akema dyno graph that got me excited. Note: akema makes the BMSBattery 'cute' motors, afaik.

Keyde and shengyi seem to take the efficiency crown for geared motors rn, but the small shengyi motor efficiency is unknown and nobody has experience with keydes due to their history of failing internal controllers and busted roller gears in the past.

..however, if a keyde performs to spec then it's worth buying one and throwing the internal controller in the dumpster. 91% efficiency peak? yes please!!! very likely it can be hot rodded!

 

[Bullfrog]

The shengyi is on my shortlist for my Schwinn Shuffle.

I should probably wait until I can actually see it before I decide :lol: .

Supposed to be delivered week of 11 Jan.

 

[markz]

Did you read the instructions?
8)

Nice semi 'bent

The bike was very well packed and had instructions for assembly.

 

[neptronix]

Did you read the instructions?
8)

No. Didn't need to. I've built so many bikes from the frame up that i just relied on my intuition. The bike was very easy to assemble compared to the 'piles of parts in bags' bikeE that i bought off eBay. :lol:

 

[neptronix]

Some news..

I convinced maxaraya to ship me some of their chromoly suspension and non-suspension forks that they experimented with in early production. It's an honor to be able to get these very unique parts.



They're oddballs. They both take 20" wheels, yet have brake bosses designed for 16".

There are a variety of front fork disc brake adapters i could use. Or just go with cantilever brakes.
Unsure which route to go. I think cantilever brakes would be strong enough for a 20" wheel, using extra long brake pads.. as long as the rear brakes are strong. And since most of the rider weight is on the rear, having stronger braking in the rear than the front isn't a problem here.

So that begs the question.. what is the strongest cantilever brake out there?


Also, after a year and a half of not having any space to work on ebikes.. i am going to be renting a workshop soon, and will be using that to do the kind of extensive work this bike needs. I also plan to prototype a series of unrelated consumer health products while i'm at it. I'm truly excited to get back to building to the degree i did 5 years ago.

 

[Bullfrog]

Some news..

I convinced maxaraya to ship me some of their chromoly suspension and non-suspension forks that they experimented with in early production. It's an honor to be able to get these very unique parts.

image001.jpg

They're oddballs. They both take 20" wheels, yet have brake bosses designed for 16".

There are a variety of front fork disc brake adapters i could use. Or just go with cantilever brakes.
Unsure which route to go. I think cantilever brakes would be strong enough for a 20" wheel, using extra long brake pads.. as long as the rear brakes are strong. And since most of the rider weight is on the rear, having stronger braking in the rear than the front isn't a problem here.

So that begs the question.. what is the strongest cantilever brake out there?


Also, after a year and a half of not having any space to work on ebikes.. i am going to be renting a workshop soon, and will be using that to do the kind of extensive work this bike needs. I also plan to prototype a series of unrelated consumer health products while i'm at it. I'm truly excited to get back to building to the degree i did 5 years ago.

Cool forks...I ended up buying Bafang kit via Amazon ($335) to put on my Schwinn Shuffle kick bike/scooter:

https://www.amazon.com/gp/product/B07QD5S44K/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

It worked pretty good in the 20" wheel on the rear of the Shuffle but did not have a temp sensor. Top speed was 21 mph on a fully charged 13s battery on it on level ground. I don't particularly care for riding a kick bike/scooter so I am selling it and going back to traditional style bicycles .

 

[neptronix]

It worked pretty good in the 20" wheel on the rear of the Shuffle but did not have a temp sensor. Top speed was 21 mph on a fully charged 13s battery on it on level ground. I don't particularly care for riding a kick bike/scooter so I am selling it and going back to traditional style bicycles .

Your results match the personal experience i relayed to you. IMHO i found the handling characteristics very unsafe.... so high speed is not possible.

You could reuse your front 20" motor on a semi recumbent bike and have a far better result. Especially on higher volts. Of course you'd need to load the front end with weight for better front end traction if you did that.. which is sort of a challenge, but doable.

 

[Bullfrog]

I have neighbor who wants to buy the Schwinn Shuffle so I am passing it along to him.

It was OK at 21 mph (top speed) but I would not want to go a lot faster...I just don't feel very "connected" to it like I do when riding a bicycle.

Did you select a motor for your "bent" bike yet...if yes, what did you go with and if you have been able to ride it, how do you like it?

 

[neptronix]

It was OK at 21 mph (top speed) but I would not want to go a lot faster...I just don't feel very "connected" to it like I do when riding a bicycle.

Yes, that whole center of gravity problem... your point of leverage over the vehicle is just too high. Basically the opposite of a semi recumbent bike in terms of where the center of gravity is.

Did you select a motor for your "bent" bike yet...if yes, what did you go with and if you have been able to ride it, how do you like it?

No, but the keyde S110 with a gutted internal controller is my top choice today.
Mounting it right ahead of the middle gear cluster is going to require some fabrication on my part. But for the highest efficiency, that would be the best place to mount it.

Probably a second candidate is the cyclone. Apparently the headway motor's gearbox lubrication and bearings can be improved upon, providing a 5-10% efficiency boost. The AFT motor kits did this. I may want to do something really crazy and use PTFE ( teflon ) to see how much efficiency i can squeeze out of 'er.

It would certainly be heavier.. i'm inquiring about the weight.

 

[neptronix]

Actually i've been doing some reading.
The 1000w lightest.bike kit ( https://lightest.bike/#FEATURES ) is probably just the ticket for driving that mid drive.

Some emails have been sent.

 

[Bullfrog]

Maybe a little off topic but I did learn from the Schwinn Shuffle experiment that a motor/controller combo that has a max of 18 +/-1A is not enough to satisfy me. With the controller transmitting the full 18A to the Bafang G020 motor in a 20" wheel, I had a top speed of 21 mph and I slowed down to around 12 mph going up a reasonable hill (no kicking/pushing). On the bright side, the Z910 connector was super convenient and a torque reaction arm will slide over it so installing the kit was very easy.

Since Grin Tech says the Z910 connector has "Continuous Phase Amps 30-35A" capability, maybe there is a motor/controller combination that will work for me...I plan to play with the "Motor Simulator" and see what I can find .

 

[neptronix]

Get yourself a programmable controller. I like my infineon clones, but there's new and more interesting stuff out there today.

One that can do at least 40 amps would be ideal.. would give you room to experiment with higher power motors in the future. :thumb:

 

[Bullfrog]

I agree...I like the Infineons and I already have the cable/software to program them.

I just ran the cheap controller that came with the kit on the "shuffle"...afraid if I pushed more amperage I'd overheat the motor and I'd never know it because it did not have a temp sensor.

Interesting combination would be the "Shengyi" driven with a Phaserunner and limit the phase current to about 50A so the Z910 connector won't melt.

Next for me is finding the donor bike for my next build...not sure what I want to do yet but I do know I want to use an 18650 based battery as opposed to LiPo :lol: .

 

[99t4]

They both take 20" wheels, yet have brake bosses designed for 16".

Excuse me if I'm missing something as it's been a while since I've messed around with cantilever rim brakes, but if the canti bosses on the forks are located for a 16" rim, how would you be able to get the pads to the proper positions for the 20" rims? :?

 

[neptronix]

The cantilever brake hole is at the top of the fork, so it should work fine for a 20".

 

[thundercamel]

As far as I know, cantilever brakes still use the bosses. Maybe you're thinking of the traditional side pull caliper brakes to use in the top hole? I'm sure Neppy knows all this already :lol:

 

[Bullfrog]

IF and that is a big "if" I was going to run brakes that clamp on the rim, I think I'd go with V-brakes...if possible.

Neppie...for brakes that clamp on the rim, what type works the best in your opinion...assuming you could use any of them?

Anybody else have an opinion on the best brakes that clamp on the rim?

My personal preference by far is disc brakes but if you don't have the capability to mount a caliper, then disc brakes are a mute point :lol: .

Reason I am asking is I am trying to decide what type of bike to build next and depending on where I head, disc brakes may not be an option.

Thank You

 

[neptronix]

I did mean caliper brakes actually, got cantilever and caliper mixed up.
vbrakes are pretty damn strong when using wide pads like the kool stop salmon.

The smaller the wheel, the higher the RPM, the more passes the pad makes across the wheel per MPH. So the world's best cantilever... err, i mean caliper brake might actually provide adequate braking.

The bike will be initially designed for a max speed of 35mph, so i think the front caliper brake might be... survivable :lol: