Small Hi-power bike Concept, reality?

[r3volved]

Stellar job dude!
Very inspiring to see your willingness and excitement to learn and solve these problems! Design is gorgeous - I want one

 

[myosis]

Thanks!
Loving that excel sheet btw, but even that is a little overwhelming for me, as I do not know what all of it means, haha, but i will find out soon enough.

I am working on new drawings, but I don't know what the standard width on the chains/belts are, at these kind of speeds they should probably be a little thicker than normal right?
Don't know if this matters, but from the motor gear to the jackshaft gear is 13 cm (measured from the rotation point of the gear/middle)
I now have a belt of 1,2cm wide on it.

 

[Miles]

I find this calculator the most useful for specifying belt drives:
http://www.contitech.de/pages/produkte/antriebsriemen/antrieb-industrie/contitech-suite_en.html

 

[macribs]

*subscribed for sure*

Amazing work n renderings, you keep honing and improving the design with a no compromise attitude. I just hope you will take orders and make this frame available to the public. I think this is the very first mid drive with absolutely no drive compromises. Perfect chain line and no heavy weight in the rear wheel. This design could be flexible enough to allow for even bigger inrunners. GM has even 10 kw and 20+ kw versions of that motor we r talking hi power'd dirt bike like performance and all weight centered.

I wouldn't stress battery placement too much, as u already got em centralized.

 

[myosis]

Haha, it will be a tight fit though that 10kw golden motor, I check it real quick but it is possible.

So I know the number of tooth on each gear and i'm going to use a 200mm HTD power belt, and a 420 bike chain from jackshaft to the wheel.
there was a problem with the set-up a had; the swing arm cloud move from side to side, I fixed it by adding an extra bar that holds the jackshaft and keeps the swing arm from moving.
Because of it the swing arm is A-symmetrical, and a little smaller.

Other than that I feel it could work
There is one thing that is still a big mystery for me.
What happens inside the jackshaft? now i know ' Drunkskunk' mentioned I should put the freewheel on the crank 'of the pedals'. but lest say I keep it on the jackshaft for now, how would it look like, what parts go into making this?

I think I need to see it to understand, maybe someone knows the right image, or could easily explain it to me
<

 

[spinningmagnets]

Your graphics abilities are excellent!

 

[macribs]

Hm. 2 set of freewheels? Warum? I am not sure my understanding of your question is correct, but after reading it over several times I think it might be. So I will try to explain to you.

Seems to me you could skip the freewheel on the left side.
When the bike is rolling the rear sprocket would turn with the wheel. With that the chain would move as well. Chain would put the "Normal Gear" in motion. That normal gear would again turn the axle normal gear is mounted to. As the axle moves the "To pedal" sprocket would be turning - this sprocket does not need to be a freewheel. This could be a normal sprocket but then you would need a freewheel on the crank to avoid pedal moving along with your axle and sprockets.

The "To motor freewheel" could be a plain sprocket as well. And even on the motor shaft you could have a plain sprocket. If you drop any freewheel on the left side and on the axle "To wheel Normal sprocket" you could even use the benefits of regenerative breaking if you like to. Ie let go off throttle and motor could go to regen and put power back into batteries.

 

[myosis]

Alright so nothing is happening inside the tube itself its just a simple bar everything is mounted on.
Its just as simple as buying a bar and three plain sprockets, will the gears than keep the bar from sliding out of the frame ?

 

[luna5k]

You'll need some bearings in there won't you? If the bar is going to rotate freely?

Your design and CAD skills are really great!

 

[sk8norcal]

That reminds me of that motoped prototype

 

[spinningmagnets]

The pedal-input can use a CSK-P "ramped roller" clutch, so that when powered and not pedaling, the "freewheel" will not make the clicking noise (from the pawls)...just an option.

 

[sk8norcal]

yes, it is that motoped prototype.

It's mostly modeled after a picture i've seen somewhere. I was however thinking of building it.
Like, will that custom swing arm work?

edit: pic added

 

[macribs]

yes, it is that motoped prototype.

It's mostly modeled after a picture i've seen somewhere. I was however thinking of building it.
Like, will that custom swing arm work?

Well and that motoped turned out a totally different look and feel - more like oh I don't know a motoped

Also ts has his own way of the jack shaft. And he will be certain to have no chain tensioning issues and a perfect chain line.
I still think ts work rocks and will make a dang fine build.

 

[punksovereign]

If i had the possibility to build a custom frame i'd make room for a Smart Pie Vector (or more powerful motor) mounted in such a way that you can attach a one way bearing on the brake side of the motor with a belt drive directly to the rear wheel.
On the rear wheel the belt driven sprocket would slide on to the cassette.

The chain coming from the bottom bracket would have to drive another sprocket with one way bearing so as not to be engaged when motor is running.

When you pedal you will turn the belt but that's it, the motor will not turn because of the one way bearing from the small belt sprocket. O maybe that one way bearing could be on the rear sprocket.

A belt tensioner will be required. The normal chain slack will be handled by the rear derraileur or some tensioner.

Sounds complicated i know but this is the only way i see where you can use quality Hollotech 2 bottom brackets and cranks and any rear hub that has a 10 speed cassette (QR or bolt on 10 or 12mm diameter axle).

I think it will make much less noise than reductions (even belts) from 4000 RPM or so.

 

[sk8norcal]

Well and that motoped turned out a totally different look and feel - more like oh I don't know a motoped

It's not the proto for the gas motoped, but for the electric version.

read it here,
https://endless-sphere.com/forums/viewtopic.php?f=31&t=22560&start=150#p822011

If the OP is buiding it for himself, he is free to do so.

I am just trying to give credit to the original guy who designed and built it.

It's definitely one of the better looking ebike frames out there.

 

[macribs]

Didn't know there even was an electric motoped in the drawing. Thx for enlighten me, credit goes where credit is due.

 

[myosis]

Yeah your definitely right, I wasn't trying to take the credits. If you have any more information about that bike please let me know. If they would just sell it, would save me a lot of money as well
That picture is about two years old for all I know, also been following the lmx 81 frame but it's just taking forever.
So I decided to build one myself. I happen to know some aluminum welders so yeah why not. Just gotta figure out 'this era of work' for now. (the reason for this post)
I'm also afraid that motoped might be to wide for me anyway, that's why I like the lmx frame better.

I've also been working on an other iteration of that bike, one where the motor is directly on the back wheel, as well as the peddle. the battery is right in the middle as well.
I'll post some renders soon, and maybe some of you can tell met if it's any better than what I already had.

But for now here's a simple screen shot of the idea:

It's a golden 5kw motor mounted on the swing arm, and the crank is on the rotation point of the swing arm.


PS: again my apologizes if I put any of you on the wrong track, but since this is just for fun, I'm just looking for stuff I like the look of and try to combine it to something I like, something that I understand and can build.

 

[macribs]

I hope you don't stray from your initial drawings, I liked that very very much.
And that would possible give the best chain line ever. Plus centralized mass, no extra weight in the rear hub. Possible use the Revolt 160 pro or the Revolt 160 Pro short can. Or the 10-20 kw golden motor.

 

[Wheazel]

Nice project! I just want to give you a heads up on the following statement from post 1.

In the battery package fits about 300 (10850) size batteries . if i'm not mistaken that's something like 90v.
I mean if i got the space why not fill it all up. Little downside the battery will weight about 7 kilos...
I know someone how can build it and it would cost 1200 euro

Personally I have not heard about 10850 batteries, maybe I have missed it, but incase you mean the much more common 18650 format,
I have some thoughts.

Those ~300 cells can be configured in a variety of setups. They dont mean 90v by default. 90v would mean using ~24 in series.

300/24 =12,5 -> 12 parallell (12cells will be left over)
You can also go down slightly in voltage to 20s and have 15parallell cells, that would use all 300 cells and give a ~75v pack.

Also the weight of 300cells is not 7kilos. I have a homemade case made out of 0.7mm steel with 180cells that weigh close to 10kg.
The bare weight of 300 cells is something like 45grams times 300. 13,5kilos.

 

[Wheazel]

Also, get to know the size of the bms you would want to use so you can make sensible designchoices with the batterybox.

 

[Miles]

It's a golden 5kw motor mounted on the swing arm, and the crank is on the rotation point of the swing arm.

What is your reason for mounting the motor concentric with the swing arm pivot point?

 

[Samd]

Nice work!

 

[myosis]

Yeah sorry I meant 18650 batteries, Thanks for the clarification! That's a lot heavier than I thought, haha.

There both on the swing arm so the distances will stay the same, it frees up a lot of space in the frame as well.

I've seen some images of a direct connection from ''a point somewhere close to the pivot'',
But I don't get how that works, won't the distance differ so much the chain will fall off?
like this one for example:

For me it just seemed simpler to put the both on the swing arm

 

[Miles]

There both on the swing arm so the distances will stay the same, it frees up a lot of space in the frame as well........

For me it just seemed simpler to put the both on the swing arm

Sure, it's what's known as a "unified rear triangle" design. You'll get some front to back movement of the pedals and the suspension is pretty useless when you're off the saddle.. The motor doesn't have to be concentric to the pivot point, though. As long as it's reasonably close to it.

 

[Rodney64]

How do you plan on keeping the chain tensioned?

I notice that you went for vertical dropouts. Maybe hororzontal dropouts will make it easier to keep the chain tensioned. Or do you plan on tensioning the chain by moving the motor. I'm impressed by your skill.