KCR PANTERA Monsterbike

kcr

1 mW
Joined
Oct 11, 2018
Messages
18
Hi Everyone.

First i need to say hallo because i'm newbie here.
Second, if someone won't undestand me please ask, i will expalin what i meant - I'm from Poland and i'm not perfect in english ;)
Third, it will be a long post :D

About year ago i have seen e-bike in music video https://www.youtube.com/watch?v=mEcePRasi4Q and i had fall in love.
For this time i spent all free hours for reading and searching for informations in ebike category.
In the same time i finished study and i recieved mechatronic engineer diploma (without brag)

So i decide to make my own vision of powerfull ebike.
I meet some people who have monsterbikes with QS 205 motors, i taken few rides offroad and on asphalt and i was ensured about way which i will design my ebike.

below you can find list of issues which i decide to solve:
1 - ebike will have central motor but this motor will be a hub motor. I decide to make universal frame for QS 205 and QS 273 because this motors it the most used and standard in my country.
2 - frame will be universal - it means that all weight and height person will find good position on it.
3 - i had take few rides on Stealth type hub motor ebike with QS205 (150A from Sabvoton) and i was satisfied, but friend (who is owner of this ebike) told me that this motor warming up dangerously and sometimes thermal protection sensors cutting out power. So i decided to make grarbox by mine, between motor and rear wheel, to reduce power needed to move in forests, dowhill etc.

Thats where idea borned. I had opened my school licenced autodesk inventor and i started to learn it and make some drawings of shapes of ebike. Main inspiration was been Albatros enduro from this forum and Neematic FR1. Based of this 2 project i decided to make frame from pipes.

The most important part for me was gearbox because it will make my ebike unique.
Firstly i tryed to addapt Shimano Alfine but powers which i will put on it makes me affraid of living time of this hub so plan was abandoned. Also I've seen few projects of bicycle gearboxes (Effigear, Pinion) but it was protect by patent law so i decide to make gearbox based on motorcycle one.

Below plnas which i set to myself.
Max revolutions 1:1 motor to wheel will give me about 90km\h speed. I don't need more in hard terrain son i will reduce recoutions on wheel to recive more Nm on it and to protect motor for overheat.
- gear 1 - ratio 2:1 - 1 rpm of motor will give me 2 rpm of wheel and about 45 km\h of max speed
- gear 2 - ratio 1,66:1 - 1 rpm of motos will give me 1,66 rpm of wheel and about 60 km\h of max speed
- gear 3 - ratio 1,33:1 - 1 rpm of motos will give me 1,33 rpm of wheel and about 75 km\h of max speed
- gear 4 - ratio 1:1 - 1 rpm of motos will give me 1 rpm of wheel and about 90 km\h of max speed

photo from designing process

comment_B54vd0VR6EzJcBcE1FSz8qOE0aU2X8Ws.jpg

after it i decidet to produce subparts

1.jpg

2.jpg

project was too precise and gears wont' move so i decided to put valve paste on it and let it rotate on radial drill

3.jpg

after assy

4.jpg

after this operations i recieved ready gearbox which is already closed and filled with oil.



Next i tryed to make full ebike project with all components like motor, wheels, frame and gearbox.
First prototype looks like this and it was abandoned because i wasn't happy of rear swing arm.

pantera v1.jpg

pantera v2.jpg

pantera v2-1.jpg

It looks terrible because all frame had 140mm width but swing arm (mounted on QS axis) were about 60-70 mm more width.
I didn't happy of it and i started again with new project regarding to knowledge recived from this project.

Second version of this project created few problems with gearbox so i decide to resign.
It was too big and heavy - better idea will be to make 2 or 3 changeable sprockets on rear wheel and chain tensioner.
Also here i decide to use QS 273 in the same frame and make it unversal for both QS 205 and 273 hub motors.

Below you can see results

pantera v3.jpg

pantera v3-1.jpg

pantera v3-2.jpg

v3-1.jpg

Also tere was one more thig that i decide to abandon - it was pedals. I dont have idewa where to put i because motor was placed on siwngarm. Maybe i should remodel it and remove QS from swingarm and connect it from pedals?

Please let me know your opionins about this project, i will be very happy for your comments.
Is this way is a good way? Or maybe should i change something? What do you thinking about it?

Kind regards for all who readed it ;)
let the force be with you:)



I don't have YT, Instagram or Facebook channles, its too early to show this project. Maybe i will create it when i will start to produce parts for ready version, now i don't have time for this actions - i prefer to waste time for designing ;)
You are the first who can see this ideas ;)
 
Why the front brake on the right side?
I think it looks great and will probably work great too.
I wish Neematic did happen.
 
Extremely impressive design and engineering work, kcr!

andrebandre said:
Why the front brake on the right side?

Because that's where it belongs. All my bicycles have flipflopped brakes. Motorcycles and all that.
 
flat tire said:
Extremely impressive design and engineering work, kcr!

andrebandre said:
Why the front brake on the right side?

Because that's where it belongs. All my bicycles have flipflopped brakes. Motorcycles and all that.

What is the purpose for have them crisscrossed?
Do they keep the bike on a straighter path when both applied hard?
Kind of ballance each other out in some way?
 
No, it's because convention for motorcycle front brake is the right bar lever. So if you ride both motorcycles and ebikes you don't want to be juggling 2 control configurations with the same lever.
 
there's no brake levers in the rendering.. only brake rotor, which is on the wrong side of fork? if its a dh bike fork, rotor is on the left.. switching brake levers from right to left is usually easy and just personal preference..
 
efMX Trials Electric Freeride said:
there's no brake levers in the rendering.. only brake rotor, which is on the wrong side of fork? if its a dh bike fork, rotor is on the left..

That's what i meant (rotor), i thought there is some reason for it that i'm not aware of.

Makes sense to have the front brake lever on the right when riding both motorcycles and bicycles.

Thank you guys both for clearing it up.
 
If you are going through the trouble of building a gear reduction then I'd look for a properly sized in runner rather than a hub motor. The power density is much higher and cooling is less of an issue.
Usually the problem is the RPM but with even a moderate first stage reduction like 3:1 it should be no problem.
 
andrebandre said:
Why the front brake on the right side?
I think it looks great and will probably work great too.
I wish Neematic did happen.

It's only design and i don't know where break clip will be. Its depends of fork type.
Thanks for good words :)

flat tire said:
Extremely impressive design and engineering work, kcr!

Thank you :)

andrebandre said:
Personally i don't see the point of pedals on high power ebikes.

That's why i will try to make this ebike without pedals. Only one reason why i tryed to add it is fact that in PL we don't have regulated law for electic vechicles and ebikes (with pedals) are treated like normal bicycles, even very powerfull ebikes.

andrebandre said:
What is the purpose for have them crisscrossed?
Do they keep the bike on a straighter path when both applied hard?
Kind of ballance each other out in some way?

Like i said - i dont know where breaks will be it depends for fork.
Thakns for comment

flat tire said:
No, it's because convention for motorcycle front brake is the right bar lever. So if you ride both motorcycles and ebikes you don't want to be juggling 2 control configurations with the same lever.

Youre right, i will keep it in my mind :) Thanks

efMX Trials Electric Freeride said:
there's no brake levers in the rendering.. only brake rotor, which is on the wrong side of fork? if its a dh bike fork, rotor is on the left.. switching brake levers from right to left is usually easy and just personal preference..

Thats right, i have to buy Rockshoxx boxxer and i thinking about it. If i will do it breaks will be on opposite side.

litespeed said:
Excellent design.

Tom

Thank you Tom :)

andrebandre said:
efMX Trials Electric Freeride said:
there's no brake levers in the rendering.. only brake rotor, which is on the wrong side of fork? if its a dh bike fork, rotor is on the left..

That's what i meant (rotor), i thought there is some reason for it that i'm not aware of.

Makes sense to have the front brake lever on the right when riding both motorcycles and bicycles.

Thank you guys both for clearing it up.

exactly

Grantmac said:
If you are going through the trouble of building a gear reduction then I'd look for a properly sized in runner rather than a hub motor. The power density is much higher and cooling is less of an issue.
Usually the problem is the RPM but with even a moderate first stage reduction like 3:1 it should be no problem.

Yes, thats why i decide to use changeable sprocket on rear wheel, If i will need power in hard terrain i can use reduction sprocket which allow to recieve 3x(for example) more power on wheel. The same situation when i will need some speed on straight way, then i will use 1:1 sprocet and i will have about 90km\h max speed
 
But you are still using a hub motor, it's just in the middle.
Much better to use a motor designed for mid-drive use. It will have better cooling and operate at higher RPM.

For gear reduction all you need is a low and direct gear which could be done with a single planetary.
 
Grantmac said:
But you are still using a hub motor, it's just in the middle.
Much better to use a motor designed for mid-drive use. It will have better cooling and operate at higher RPM.

For gear reduction all you need is a low and direct gear which could be done with a single planetary.


So you thought that hub motor in a middle is a bad idea?

Btw. Do you know powerfull hub motor which i can use instead? I don't have knowledge in other motors than hub, my friends have hub ebikes too so i don't know where to find informations.
If you know motor with simiar or better preformance like QS 273 for similar or better price and good dimesions-weight ratio please let me know - each information will be very helpful. I can still change project because i didn't started production of parts yet.
 
For an electric motor, the transmission can have much wider ratios between gears. In most cases, just two or three speeds would be enough. Most people run with a single speed.

Here's a bike with a design similar to your build:
Typhoon Pro
I think this is the frame, or at least an extended version which is probably more ideal. Cheap and will be back in stock in two months.

++ not the same frame. Not related to the topic.
 
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