Mid drive with a proper Q factor + spacing - does it exist?

[BalorNG]

Here is what I've had in mind:

According to my experience with a similar bent, this might look dangerously close to, ahem, your body parts, but actually there is no way for you to touch the motor unless you really try to.
Plus, a system of boxed motor support/shaft support that I've implemented for myself makes that impossible anyway:

 

[Deafcat]

The mid drive requirement is not so easily dropped.

With a semi recumbent bike, i have a very light front end, and could use a mid drive as ballast to prevent power wheelies. Ideal place to put a motor is up front, ideal traction wheel is in the back because >80% of the rider weight sits on the back. A mid drive is a good idea here.

How about dual hub motor? Independent ESCs with independent batteries, for twice the regen capacity... dual hub is a lot of fun and it will distribute the weight, and regen braking nicely.

 

[BalorNG]

The mid drive requirement is not so easily dropped.

With a semi recumbent bike, i have a very light front end, and could use a mid drive as ballast to prevent power wheelies. Ideal place to put a motor is up front, ideal traction wheel is in the back because >80% of the rider weight sits on the back. A mid drive is a good idea here.

How about dual hub motor? Independent ESCs with independent batteries, for twice the regen capacity... dual hub is a lot of fun and it will distribute the weight, and regen braking nicely.

I really do not think that it will help. This recumbent has way too high seating position and due to rider 'long-legginess' - rearward CG bias to provide a ton of acceleration before pitching the rider right over... unless you install 40 pounds of battery, right The front motor will spin out and it can result in a quick fall due to loss of front traction.

You want something like Horn's "motocumbent" for that
https://www.odd-bike.com/2019/07/guest-post-robert-horns-rohorn-two.html

I really wanted to try and experiment with VPS like he has, but this is complex and does not solve 'wind steer problem'...

 

[neptronix]

How about dual hub motor? Independent ESCs with independent batteries, for twice the regen capacity... dual hub is a lot of fun and it will distribute the weight, and regen braking nicely.

I have thought about that, but the front wheel isn't very useful since it is so light. I'd have traction issues. Most i'd put on the front wheel is a 250w geared motor.

I'm kind of ruminating over what baldor said. Looking at the frame, there is no really good place to mount a motor. Because i sit with the seat fairly far back.. the suggested motor positioning is a little suspect and i suspect there will be pants to chain contact.

Let's be honest.. the bike is hard to electrify!

 

[neptronix]

You want something like Horn's "motocumbent" for that
https://www.odd-bike.com/2019/07/guest-post-robert-horns-rohorn-two.html

that's awesome!!

 

[Hummina Shadeeba]

That’s the coolest, raciest, most non-dorky recumbent I can imagine

 

[markz]

Please don't choke on the gasser fumes by golly or your faux coat might stain and disturb the tree's and whales.

Not the safest vehicle on the road is it. So low, no one can see the fella, but he's just using it to race so hope he wins lots of races.
"Robert Horn's RoHorn Two Wheel Steering Recumbent Racer "
Hey, I know a Horn and wonder if they're related.
HORN is ranked as the 410th most popular family name in the United States with an estimated population of 86,212.
https://www.mynamestats.com/Last-Names/H/HO/HORN/index.html

That’s the coolest, raciest, most non-dorky recumbent I can imagine

 

[BalorNG]

How about dual hub motor? Independent ESCs with independent batteries, for twice the regen capacity... dual hub is a lot of fun and it will distribute the weight, and regen braking nicely.

I have thought about that, but the front wheel isn't very useful since it is so light. I'd have traction issues. Most i'd put on the front wheel is a 250w geared motor.

I'm kind of ruminating over what baldor said. Looking at the frame, there is no really good place to mount a motor. Because i sit with the seat fairly far back.. the suggested motor positioning is a little suspect and i suspect there will be pants to chain contact.

Let's be honest.. the bike is hard to electrify!

With a belt drive (that you want to have anyway) there is absolutely no problem even with occasional contact, but than wearing loose pants is not exactly a good idea on a bicycle anyway
OTOH, you can simply install a nice, light 250w rear hub and a larger battery on the handlebars like it is suggested on the manufacturer website - the bike will not be a speed demon, but a comfortable cruiser.
To be frank, if you want a 'speed demon' you want something like mine/horn bike - longer, larger wheels, lower seat (not too high for practicality, around 20 inches high is great compromise).
CLWBs (I have one, I know) are cool bikes, but high speed handling are not their forte...

 

[BalorNG]

Please don't choke on the gasser fumes by golly or your faux coat might stain and disturb the tree's and whales.

Not the safest vehicle on the road is it. So low, no one can see the fella, but he's just using it to race so hope he wins lots of races.
"Robert Horn's RoHorn Two Wheel Steering Recumbent Racer "
Hey, I know a Horn and wonder if they're related.
HORN is ranked as the 410th most popular family name in the United States with an estimated population of 86,212.
https://www.mynamestats.com/Last-Names/H/HO/HORN/index.html

That’s the coolest, raciest, most non-dorky recumbent I can imagine

Lol, he wanted an electric racer (he did a lower powered one), and it would be actually better (AWD!) but to be viable as a *racer* it would be MUCH, much more expensive compared to pulling a motor from a donor bike...

 

[neptronix]

A belt drive would help with the pants shredding factor but creates the need for custom 'sprockets' of particular offsets/sizes. Not worth the hassle and money.

The electric Ray 2 is the least appealing electric bike i've ever seen. Battery on the handlebars is ugly, becomes a flammable front bumper, and creates steering effects and probably some extra wear and tear on the headset.

Because of the weight distribution issue on the maxaraya ( i easily do wheelies on pedal power ), in their electric version, the battery acts as ballast to keep the front end on the ground.

Best thing we can do is put the battery and motor up front as far as we can. That always means using a mid drive.

 

[neptronix]

I have an idea.

How about, on my bike, putting a mid drive in the middle mid drive section ( Hey, it's a 68mm BB! ) and converting the pedal drive side to drive the right instead of the left.. ?

There are also chainring adapters for the BBS02/HD, maybe tongsheng also, that bring the sprocket inward and (probably) give me enough room to adjust the driveline offset.

That begs the question.. which mid drive has the least extra width, or most correctable extra width on the drive ( right ) side?

 

[Chalo]

I think the battery on the Maxarya's steering mast is probably the least of the factors that would make it ride badly. It looks to me like the frontmost part of the battery is half a meter behind the frontmost part of the bike, so not a bumper unless you nail a railway crossing gate. It's set at a minimum distance from the steering axis, so it should have less inertial effect than a sack lunch and a water bottle in the handlebar basket of a normal bike. I would not be very surprised if a 'bent were debilitated by that, though.

Given what headsets do to manage contact patch forces, I doubt any of them will notice an extra ten pounds stuck on a stick. However, if that's a folding joint for the steering mast I see, it might get beat up by the added bending moment.

My biggest beef with the battery location is that it's up pretty high, so when the bike falls over, the pack could be moving fast when it strikes the ground. But there are plenty of worse things about the bike than that.

 

[Chalo]

That begs the question.. which mid drive has the least extra width, or most correctable extra width on the drive ( right ) side?

BBSHD has the widest selection of different chainring offsets. It has some, not a lot, of leeway to refine chainline or chainstay clearance when you install it.

 

[neptronix]

The battery can be a bumper if a car slams it's brakes in front of you and you hit it. Reverse it's position and now you probably have it hitting your knees during a turn.

Any extra unwanted steering input beyond the absolute minimum is unacceptable to me.

Also, that folding stem is garbage. It had way too hard of a time not bending inwards despite being clamped down like crazy. It also put the handlebars in a very bad position for cornering. I junked mine.

 

[neptronix]

BBSHD has the widest selection of different chainring offsets. It has some, not a lot, of leeway to refine chainline or chainstay clearance when you install it.

It's also relatively quiet, no?

 

[Chalo]

BBSHD has the widest selection of different chainring offsets. It has some, not a lot, of leeway to refine chainline or chainstay clearance when you install it.

It's also relatively quiet, no?

Quieter than any brushless hub motor I've used (trap wave controllers only, so far). The big spur gear starts to make a little noise when it gets dry of grease.

 

[neptronix]

Hm

I'm looking at the CYC Pro X1 motor and bracket kit ($445 when you take the accessories out, wow):
https://www.cycmotor.com/product-page/x1-stealth-motor-gearbox

This is said to be compatible with 68mm BB's, but that shaft really sticks far out. I think there'd be severe problems with lining things up on a regular bike.

Perhaps this would drive the bigger outer chainring of the bike with minimal/no need to monkey with offset. All i really need is a 12mm keyed shaft freewheel, disc brake, or sprocket adapter, and i'm in business, and dodge all the offset issues of putting the mid drive on the crank. The location also improves the bike's weight distribution problem a hair.

 

[markz]

Why not have the battery on the back of the seat, as low as possible.

I was watching a yt video last night on Cyclone 3kw install from Luna, another video popped up of a guy using split collars to mount his mid drive, it was a standard frame tube I think he said 1-1/4" I will see if I can find it again. He's got some weird name, handlebar mustache guy. Livingstone on his channel NewJerusalemTimes
Just giving you idea's - https://www.youtube.com/watch?v=3FVt1rPqHIg
The frame in the pic looks to be non round, more elongated.

Or raise the seat up and place battery under the seat, higher c.o.g.

Battery on the inside of the handlebar instead of outside might get in way of pedalling.

 

[neptronix]

Why not have the battery on the back of the seat, as low as possible.

That would worsen the wheelie problem. With how far back i sit, and how i like to have the seat leaned back much more than stock ( as you see in the pics ), some of the battery weight would be behind the axle.

Realistically, the bike has a 90%/10% weight balance. Wheelies and front traction will always be an issue. So the more weight i get up front front, the better.

Can't raise the seat, i plan to modify it to lower it to improve the handling on fast turns. The bike is already 10mm taller than stock, so the center of gravity already needs some help.

 

[BalorNG]

The battery can be a bumper if a car slams it's brakes in front of you and you hit it. Reverse it's position and now you probably have it hitting your knees during a turn.

Any extra unwanted steering input beyond the absolute minimum is unacceptable to me.

Regarding the weight distribution... Yes, it will create steering input. However, it is not an *unwanted* steering input
The problem of most recumbent bikes is a 'tiller effect' - overall weight distribution of the steered bits being *behind* the steering axis (note, it is not just the bars/shifting bits - this is also your HANDS and a considerable part of your arms).
The most noticeable effect is almost complete impossibility of hands-free riding. Installing a battery like this will likely allow you to ride handsfree (provided you at least capable of that on an upright bike, not everyone does ), and added steering inertia will be negligible because the *distance* from axis of rotation to CM of the battery is really small. Overall effect when 'just riding' should be positive overall - just try attaching a similar weight from a similar distance (like a couple of lifting irons?) and see for yourself.

As for 'custom sprokets' - they will need be 3d printed anyway (at least the 104BCD one, but that's like 5-click job, one for the motor costs like 5$), and after ascertaining the distances there is wide selection of HDT 5m belts - it's exact length can be calculated according to distances between motor shaft and middrive axis and choice of sprokets...
However, since your middrive is also a conventional bottom braket (I've thought this is a complex unit that also serves as suspension pivot! Otherwise I'd suggest that myself...), it absolute no-brainer to install the middrive there indeed, thought personally I find DIY stuff more satisfying (not to mention more powerful and more efficient, ehehe)

 

[BalorNG]

Why not have the battery on the back of the seat, as low as possible.

Realistically, the bike has a 90%/10% weight balance. Wheelies and front traction will always be an issue. So the more weight i get up front front, the better.

... did you actually measure that? The bike will night be completely unrideable - for instance, you will not be able to start up any noticeable incline without doing a whelie instead - I know because I actually *do* have a bike (actually a modified trike ) such a weight distribution

(Obviously, it is just a fun experiment).
I thin your weight distrubtion like more 75/25. Easily to measure using floor scales...

 

[BalorNG]

*mispost*

 

[BalorNG]

*more double post, grumble*

 

[BalorNG]

Actual theory (and math!) behind keeping balance on singletrack vehicles (not necessarily bicycles, btw) is pretty damn complex.

I suggest you watch this video, very enlightening.

https://www.youtube.com/watch?v=2Y4mbT3ozcA&t=1s

Since I'm personally very clumsy, I've had to learn a LOT about it and design my own bents around my personal limitations from basic principles...

 

[neptronix]

No, i didn't exactly measure it, maybe i'm exaggerating and it's 80%-20% :lol:

Yeah i noticed the maxaraya had a tiller effect right off the bat with it's handlebar design and angles. I immediately chucked the entire setup and went to wide BMX bars. Dramatic instant improvement. Very wide handlebars also makes the bikeE a joy to ride despite having a silly size front wheel and short wheelbase compared to these big bois.

That trike doesn't look fun, let's say!

I had to learn a lot of new things since getting myself into CLWBs, Laid back bikes are a completely different world.

I could fairly easily get a sprocket adapter that would slide on the CYC or have one machined by a company that plays around with go kart and gas powered bikes out here.

I wish i could do more DIY, but i don't have a shop or anything near the tools i need. Also, i'm a level 1 machinist, so even if i had the tools.. i have some mistakes to make and things to learn.