Custom frame for the Cyclone Coaxial motor
- Thread starter Chambers
- Start date
Really great design, congratulations @chambers!
CNC means Custom Cyclone Coaxial?
Referring to your battery compartment design, you will get with 14s11p configuration approx 1700kWh battery capacity considering VTC6 cells. Thats perfect! I would defenetively go with 14s configuration for the Cyclone.
Please pay attention how you are going to insert the whole battery pack once it is soldered and assembled. Assuming that you insert the pack from the bottom of the downtube, a big tube cover will ease your life - also for maintenance purpose.
Keep us updated on how you progress - your design is really hot
CNC means Custom Cyclone Coaxial?
Referring to your battery compartment design, you will get with 14s11p configuration approx 1700kWh battery capacity considering VTC6 cells. Thats perfect! I would defenetively go with 14s configuration for the Cyclone.
Please pay attention how you are going to insert the whole battery pack once it is soldered and assembled. Assuming that you insert the pack from the bottom of the downtube, a big tube cover will ease your life - also for maintenance purpose.
Keep us updated on how you progress - your design is really hot
I think flipping it back to 85mm wide 100mm tall is a big mistake. None of what he wrote is true, Q factor is pedal to pedal, and it will be at least 160mm anyway. So the downtube getting a bit wider won't be noticable at all.
This is my coaxial, 104mm box, I've never had the box touch me on accident, it is actually useful for extra control to squeeze between your legs for let's say a no hander. As your legs complete sort of a triangle from the seat down to the pedals, with the battery in the downtube there is no chance of interference.
You will have the chainring holder sticking out of the 105mm plane on one side, and the motor on the other. Shrinking it makes no sense, you won't be able to use that space anyway.
In addition, here the cells would be resting on their bottoms instead of each further row putting extra pressure on all rows below them, and the center of gravity would be lower, same with the visibility profile from the side.
The 48v idea is terrible, if you want 5kw, you would need 100a+ with 48v, while just 75a with 72v. Even at 72v it spins only 4500rpm.
This is my coaxial, 104mm box, I've never had the box touch me on accident, it is actually useful for extra control to squeeze between your legs for let's say a no hander. As your legs complete sort of a triangle from the seat down to the pedals, with the battery in the downtube there is no chance of interference.
You will have the chainring holder sticking out of the 105mm plane on one side, and the motor on the other. Shrinking it makes no sense, you won't be able to use that space anyway.
In addition, here the cells would be resting on their bottoms instead of each further row putting extra pressure on all rows below them, and the center of gravity would be lower, same with the visibility profile from the side.
The 48v idea is terrible, if you want 5kw, you would need 100a+ with 48v, while just 75a with 72v. Even at 72v it spins only 4500rpm.
Tommm said:I think flipping it back to 85mm wide 100mm tall is a big mistake. None of what he wrote is true, Q factor is pedal to pedal, and it will be at least 160mm anyway. So the downtube getting a bit wider won't be noticable at all.
This is my coaxial, 104mm box, I've never had the box touch me on accident, it is actually useful for extra control to squeeze between your legs for let's say a no hander. As your legs complete sort of a triangle from the seat down to the pedals, with the battery in the downtube there is no chance of interference.
You will have the chainring holder sticking out of the 105mm plane on one side, and the motor on the other. Shrinking it makes no sense, you won't be able to use that space anyway.
In addition, here the cells would be resting on their bottoms instead of each further row putting extra pressure on all rows below them, and the center of gravity would be lower, same with the visibility profile from the side.
The 48v idea is terrible, if you want 5kw, you would need 100a+ with 48v, while just 75a with 72v. Even at 72v it spins only 4500rpm.
I get what you're saying Tommm,
And thanks for the pics!
I am much more of a fabricator than a draftsman so I will have a much better feel for it once I start building - No reason why it can't be altered dimensionally at any point. I built a cardboard model (last week?) of a 100mm wide version and it just looked kind of wonky - This was of a much earlier revision though and lots of things have changed since then!
In any case no final decisions will be made until I have all the parts on hand - Theoretical measurements vs actual ones don't always work. So this should be thought of as a conceptual shape rather than a finished product at this point.
BTW I appreciate your frank feedback :thumb:
OK I got you! 20s7p for the Cyclone motor with 1.5:1 fix ratio on the left drivetrain side. Cyclone homepage says 200~750rpm which is supposedly achieved with the internal planetary gear set 6:1.
So Tomm, the 4500rpm @72V is referred to the motor speed not output speed on the crank shaft, right?
I assume that water bottle holder on the down tube may not be possible with that design.
So Tomm, the 4500rpm @72V is referred to the motor speed not output speed on the crank shaft, right?
I assume that water bottle holder on the down tube may not be possible with that design.
Elaguila said:
Correct, 4500 motor, 750 crank. With 30t front 50t rear (1.66:1) that will net you around 45kph (28mph) or 54kph (34mph) with field weakening. This is the shortest gear possible with bike components but you don't want shorter anyway. +%20 longer ~1.45:1 would be ideal for a single speed setup.
Tommm said:
Really good insights for the 30t front/50t rear, thanks.
I´ve only experienced the Cyclone coaxial with Kelly controller and with Cyclone´s original controller. And field weakening is something which I was told to avoid (however for different applications, not for e-bike purposes): torque drop and current rise. But you are right, motor speed may increase and so does bike speed.
Anyhow, by using such a cool bike on trails means rather high torque and max. 45kph as you´ve mentioned before. Is there any controller you could recommend since you seem a rather experienced guy with field weakening setup?
I love it, the first one looks just like a factory bike.
One big thing, the more it shapes like a regular factory emtb, the less trouble people/cops will give you.
The reason for this is they think
factory/professional look -> store bought -> legal by necessity
So if they think it is factory, they will think whatever it is, it is legal. Some shroud would be cool to hide the controller eventually.
Also in the slim version you could easily fit a bottlecage and mount, there are fake bottles with a zipper in the middle you can pack with tools/accessories/valuables. It would be well protected below the top tube.
I made some pics showing center of gravity for battery+controller on the two as well as a design I would personally go for.
The shape of the battery would be a simple triangle. Red box is the controller.
One big thing, the more it shapes like a regular factory emtb, the less trouble people/cops will give you.
The reason for this is they think
factory/professional look -> store bought -> legal by necessity
So if they think it is factory, they will think whatever it is, it is legal. Some shroud would be cool to hide the controller eventually.
Also in the slim version you could easily fit a bottlecage and mount, there are fake bottles with a zipper in the middle you can pack with tools/accessories/valuables. It would be well protected below the top tube.
I made some pics showing center of gravity for battery+controller on the two as well as a design I would personally go for.
The shape of the battery would be a simple triangle. Red box is the controller.
Thanks, I agree with you on this one - it does look more factory.
I think the right-hand bike will be more nimble at speed while the left hand will be more stable at lower speeds - The centre of mass is closer to the centre of the bike on the right - lower and further forward on the left.
This is similar to some of my early designs - However it definitely doesn't meet the 'factory professional look' criteria/Will get a lot more second looks vs a more traditional shape.... Problem for some - Not for others.
I ran a poll on ES Facebook last night for left-hand bike vs right-hand out of curiosity - So far it's close to 50/50 which surprised me. It's always interesting to get a bunch of different opinions on aesthetics, The more you stare at something the more you get used to it and what once looked awkward becomes normal.
Cheers.
Chambers said:
I think lower cg has only advantages on any vehicle. You want the top of the bike to be flickable sideways while riding so you can thread trees/cars while in motion. You want the bottom of the bike to have weight even while cornering so you keep traction and rocks/roots don't throw you upside down.
I haven't seen one example so far where it is more advantageous to have it higher, moto gp bikes are completely slammed, and in dirt bikes it is also brought up as an improvement if the new model has lower cg than the outgoing one.
I have seen some downhill racing teams tack on lead weights to improve stability and traction of the bikes and they always put it right under the BB.
I do agree the triangle shaped one would make it less stealth, emtb manufacturers are busy trying to make them look like mtbs as much as possible to raise acceptance.
Tommm said:
I am certainly no expert on the subject but the above image from Honda gives some insight into what I meant.Between these two e-bikes I don't think the difference would be large enough to tell - Appropriate rake trail and suspension set up would make much more of a difference IMO.
Chambers said:
I am sure the high center of gravity is because of necessity not by choice, the turning circle agility is better for a shorter bike (as with cars) and the result of the shorter wheelbase is you need to pack your components more vertically. If a higher center of gravity would be simply better, they could put any component as high as they wanted, and bikes would look completely different.
Motorbikes can also afford a steeper head angle since their steering is oil dampened on the high end making them both maneuverable and stable at speed.
Tony Foale has a great book on chassis and suspension design, It's motorcycle based but the concepts translate to any two wheeled vehicle. https://motochassis.com/product/book-motorcycle-handling-chassis-design/
Of course when it comes to bicycles we have human input to consider as well - Pedal bob etc.
I'm a fan of the saying - 'If you can't make it perfect, Make it adjustable.'
Of course when it comes to bicycles we have human input to consider as well - Pedal bob etc.
I'm a fan of the saying - 'If you can't make it perfect, Make it adjustable.'
If I was doing my frame, I would copycat something that works well, while still understanding what I am doing and why.
It has to be very progressive though with small leverage, as this bike will be much heavier, you need a long stroke (dh shock) or you might struggle to find a shock with enough resistance.
It has to be very progressive though with small leverage, as this bike will be much heavier, you need a long stroke (dh shock) or you might struggle to find a shock with enough resistance.
Downhill damper would absolutely make sense. If bike geometry allows, the use of e.g. 240x76mm or 210x55mm or any “standard” damper would be great since there are many rear shocks with air/coil springs available on the market. The increased package weight could also be adjusted by different lbs coil springs.
Yes - emulating existing working designs is the first logical step, Thats what I have done here - While making allowances for the extra weight and speed.
There are basically no DIY ebike kits on the market that have linkage rear suspension and allow for this size of battery and speed - at least none I could find.
Plenty of nice frames for the bafang drives at a max of 2500w with small batteries then you end up in stealth/stealth clone territory with single pivot suspension and motorcycle looks - No really attractive mid-drive frames in this catagory either that I know of - if you know of one please post a link for everyones benefit.
There are basically no DIY ebike kits on the market that have linkage rear suspension and allow for this size of battery and speed - at least none I could find.
Plenty of nice frames for the bafang drives at a max of 2500w with small batteries then you end up in stealth/stealth clone territory with single pivot suspension and motorcycle looks - No really attractive mid-drive frames in this catagory either that I know of - if you know of one please post a link for everyones benefit.
The goal of this project is to design and build an integrated 'bicycle like' frame for the cyclone coaxial that is 'better' than the elite frame.
A few people have contacted me via PM and FB asking to purchase this frame. This is not a sales thread, And at this point nothing is for sale -
Once I have built and tested the final version I may offer something for sale but that would be in a specific sales thread.
People have also asked for plans... same applies, I am not willing to supply plans until I have built and tested the unit, I cannot in good concience supply for plans for something that is untested.
I do appreciate the interest.
Thanks.
A few people have contacted me via PM and FB asking to purchase this frame. This is not a sales thread, And at this point nothing is for sale -
Once I have built and tested the final version I may offer something for sale but that would be in a specific sales thread.
People have also asked for plans... same applies, I am not willing to supply plans until I have built and tested the unit, I cannot in good concience supply for plans for something that is untested.
I do appreciate the interest.
Thanks.
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