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Discussion Starter · #1 · (Edited)
Hi everyone!

It's been a while since I posted so thought it might be a good time to jump back into the community.

Back in 2013 I did a budget cafe conversion on a KZ440 LTD which had a build thread on this forum, so decided to keep going! About a year after the original build I got a Street Triple R and the bike sat mostly idle after that. The build actually inspired me to go back and study Mech Engineering where I was involved in the uni's solar car team for the last few years of my degree. Unfortunately the World Solar Challenge was cancelled for 2021 because of COVID, and so I didn't get the chance to be part of it all before graduation. Being part of the design team for this got me super interested in EVs though - so I decided to do my own as a graduation present :D

The good news is my frame mods are still in good shape from the original KZ build, making a great foundation for a complete resto-mod. I've also decided to open source the project so all designs/CAD files etc can be shared.

Fuel tank Sky Tire Wheel Motorcycle


I guess the thread title kind of gave away the intent of the refresh... an electric conversion, but the build will include a fairly major overhaul. The intent of the build is to keep it as true to the original cafe design language as possible, while completely modernising every part of it. A fair bit of planning and modelling has gone into the setup so far, but now the direction has been locked in and the parts are being slowly rounded up.

The build will retain 4 parts from the original bike: The frame, swing arm, front wheel and tank. The DCC cafe seat form the first build will also stay because its in great condition and suits the look im chasing. The front end is being modernized with KTM Duke 390 parts almost in its entirety. This was selected as the OE steering bearings are the same size, the fork heights are very close, the axles are the same diameter, and the weight of the bike will be very close to the 390, so I shouldn't need to adjust the cartridges. The only modification is the design of a shortened steering stem to make it all fit nicely without bearing cups or spacers.

The brake disk and ABS/speedo sensor disc will need to be custom made for the KZ wheel, as well some adjusted axle spacers, however this should be fairly straight forward.

Product Rectangle Slope Font Schematic


The motor is an 8kW (16kW peak) QSmotor hub drive, coupled to a Kelly Controller. I chose this setup because the bike will be for standard road use, and the OE rear wheel and sprocket are within a few kg of the hub motor so at least some of the riding characteristics of the bike should stay similar to before.

Power will be from a 24S pack of 74Ah LiPo pouch batteries, using a dilithium BMS and charging from a Thunderstruck TSM2500. This charger is amazingly configurable, and has the look of an old school cylinder head that will really suit an exposed, finned look on top of the battery and controller area. I made up a spreadsheet power model to calculate a decent traction pack capacity, which at 7.7kWh should conservatively give a 100km range at 100kph constant speed (PM for power model sheet). The design is also expected to have a 0-100 acceleration rate of a little over 6sec. Perfect for a daily ride :)

The 12V system is isolated and built around an Antigravity litium battery, with lighting and auxiliaries controlled using a motogadget m.unit (if I can get my hands on one). I've also sourced a 400W DC-DC converter to keep the 12V system charged form the main traction pack (and also to support another super secret accessory that uses just under 200W...)

Tire Wheel Automotive tire Motor vehicle Tread
Automotive lighting Motor vehicle Tire Light Automotive tire


I decided against using the axle stay plates provided by QS motor due to fit, plus they looked a bit flimsy and I don't want to chance any rounding out over time. The new stays and spacers are several times thicker to reduce stress in those key areas. My design also locks into the rear lower suspension bolt, so it should minimise any play in this region.

Bicycle part Automotive tire Camera accessory Wood Tire
Handwriting Font Line Wall Rectangle



Below is the draft circuit diagram for the HAZV circuit. I've been super lucky to have a fair bit of input and validation from EV West and Thunderstruck to get it to this stage. They have both been fantastic to deal with so will give them all the business for this build where I can.
Product Rectangle Schematic Font Parallel


that's it for now as I'm waiting for the next lot of parts to turn up, but keen to hear feedback if this has piqued anyone's interest.
 

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Very nice!! I teach some rudimentary CAD on my forum. I don't think it would be proper to post a link here. My forum is completely free. Since you are a student, you can get Rhino64 ED for $200 dollars. This programs is a full 3D modeling program, accepts most major formats, exports into even more. NASA used it to model the Space Shuttle tiles. It is capable of N.U.R.B.S. modeling (Non Uniform Rational Bezier Curves). It is used in many movies, manufacturing, there are literally 1000's of tutorials on YouTube to get you started. Since you are a student, you can get it for around: $195, instead of $1000 dollars. You can load it onto 3 computers at the same time.. While it says student license, it is the fully functional version and you can use it commercially. If you contact me via a Private Conversation, I can give you examples, and start you down a path that will truly broaden your horizons. I find it better than AutoCad.


This guy made a nice electric bike using a CB200. It cost him $60K to get it to a point where he could get decent range. He now sells them for around $5K.

Link: https://cleantechnica.com/2020/08/1...motorcycles-into-custom-electric-motorcycles/

Here's the CAD link: Rhinoceros 3D
 

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Discussion Starter · #3 ·
Very nice!! I teach some rudimentary CAD on my forum. I don't think it would be proper to post a link here. My forum is completely free. Since you are a student, you can get Rhino64 ED for $200 dollars. This programs is a full 3D modeling program, accepts most major formats, exports into even more. NASA used it to model the Space Shuttle tiles. It is capable of N.U.R.B.S. modeling (Non Uniform Rational Bezier Curves). It is used in many movies, manufacturing, there are literally 1000's of tutorials on YouTube to get you started. Since you are a student, you can get it for around: $195, instead of $1000 dollars. You can load it onto 3 computers at the same time.. While it says student license, it is the fully functional version and you can use it commercially. If you contact me via a Private Conversation, I can give you examples, and start you down a path that will truly broaden your horizons. I find it better than AutoCad.


This guy made a nice electric bike using a CB200. It cost him $60K to get it to a point where he could get decent range. He now sells them for around $5K.

Link: https://cleantechnica.com/2020/08/1...motorcycles-into-custom-electric-motorcycles/
Thanks for the info Kawasakian. I've been using mainly Inventor Pro and Solidworks but found them to be far from ideal for freeform modelling. Id be interested in trying alternatives so Rhino has tweaked my interest. Does it have any FEA capability?

The cost of this build is circa 15k with the front end conversion.
 

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In short, Yes, Rhino can do FEA. Kind of beyond my pay scale to be honest. I tend to over engineer. I have made recumbent bikes and trikes, parts for aircraft, carts, etc, usually rebuilding and improving the original structure based on an assessment of where the original part failed. I do nothing that is critical though.. I also do a lot of reverse engineering. Basically, I am a machinist, mold maker, and programmed 4, 6, and 8 axis machines, designed fixtures and end mills for composite cutting. That's about my limit. I'm old enough that learning something very new and in depth is too much. I have enough friends who can help my for stress analysis. A family member designed the 1st half of the JSF 35 engine for Pratt and Whitney (the actual vanes, and compressor wheels) and all the asssociated manufacturing that is necessary. He helps me out with stuff that gets over my head, which is rarely though, as I tend to stick into areas I know.

This link is for FEA use in Rhino3D:

This link is for FEA, Link =
 

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I used to teach CAD/CAM using Unigraphics software and we touched on FEA. Its a fascinating subject.
I consider myself semi-retired at this point although I do some consulting work from time to time. My background is similar to Kawasakian: Machinist/Toolmaker/CNC programmer/Educator.
 

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The apprenticeship programs failed and broke down in Connecticut. It became a free for all, learning from where ever you could get it. Taking less money to learn more. It's disgusting what happened in Connecticut. The same thing happened in the Electronics field. I got my first 10000 hours in a school, but could not get a V1 liscense as the whole system broke down. The state told me to open a repair shop, and they would close me down only if they got complaints. For many years I was a Sony authorized repair shop, with no formal on going training. I finally went completely independent, telling Sony they would have to pay retail like everyone else if they were not going to give me the technical manuals I needed. They coughed them up, but I ended up going completely independent. I never got complaints. I had a few nuts, but when you have a business that grows like a tree, you always get some nuts. I found audiophiles were my best customers. I was the only person in the area who would recone vintage speakers, even wrapping speaker coils. I fixed many Bang and Olufsen speakers that people were desperate to repair. I never met anyone else who would recone or fix the foam surround on these speakers. I designed my own electrostatic speakers and sold a couple of sets, but because of the voltage, I didn't want the liability. :)
 

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Discussion Starter · #8 ·
Great thread and exciting project. I will follow this closely since I plan to do a mini-bike EV conversion myself.
For 3D CAD I use Fusion360 which is free for non-commercial use.
Thanks. I've also dabbled in Fusion 360 but ended up sticking with Inventor as its not a cloud app. That said Fusion has some really nice generative design features that would be a lot of fun to play with!
 

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Discussion Starter · #9 ·
In short, Yes, Rhino can do FEA. Kind of beyond my pay scale to be honest. I tend to over engineer. I have made recumbent bikes and trikes, parts for aircraft, carts, etc, usually rebuilding and improving the original structure based on an assessment of where the original part failed. I do nothing that is critical though.. I also do a lot of reverse engineering. Basically, I am a machinist, mold maker, and programmed 4, 6, and 8 axis machines, designed fixtures and end mills for composite cutting. That's about my limit. I'm old enough that learning something very new and in depth is too much. I have enough friends who can help my for stress analysis. A family member designed the 1st half of the JSF 35 engine for Pratt and Whitney (the actual vanes, and compressor wheels) and all the asssociated manufacturing that is necessary. He helps me out with stuff that gets over my head, which is rarely though, as I tend to stick into areas I know.
Sounds like some pretty decent experience none the less. FEA is definitely a bit of a dark art... especially when starting out.
By chance have you had much to do with tolerancing shafts for precision bearings?
 

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Making and using. Making plain bearings, using all kinds of other bearings. I worked on critical components of helicopters (rotor head) and sometimes that removing a bearing race from the transmission housing of a Sikorsky CH53 series transmission housing. Those parts are so damned expensive, it is a nerve wracking procedure. It is done with a Carbide End mill, you plunge the end mill a few thousandths at a time, like maybe .002", and move in, the depth being preset. When you finally cut through the race will snap in. You must make sure the race does not get stuck with the end mill and spin and foul the transmission housing surface where the bearing is pressed in.. When I rebuild engines with plain bearings, I always use "Plastic-Gauge" to measure the tolerances. With bearings, I was following an engineers orders. If you have a specific question, ask, I may or may not have the answer. No way or knowing. I am always glad to help anyone when I can, but I do know my limits. As far as shafts, I used to have to straighten shafts after the screws were machined into them. The biggest where 8" inches in diameter, and 15' long. They were used for raising and lowering missiles on some kind of ship. Maximum out of round was .002" +/- over the full length. A massive cage went over these long screws. :)
 

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Discussion Starter · #11 · (Edited)
Making and using. Making plain bearings, using all kinds of other bearings. I worked on critical components of helicopters (rotor head) and sometimes that removing a bearing race from the transmission housing of a Sikorsky CH53 series transmission housing. Those parts are so damned expensive, it is a nerve wracking procedure. It is done with a Carbide End mill, you plunge the end mill a few thousandths at a time, like maybe .002", and move in, the depth being preset. When you finally cut through the race will snap in. You must make sure the race does not get stuck with the end mill and spin and foul the transmission housing surface where the bearing is pressed in.. When I rebuild engines with plain bearings, I always use "Plastic-Gauge" to measure the tolerances. With bearings, I was following an engineers orders. If you have a specific question, ask, I may or may not have the answer. No way or knowing. I am always glad to help anyone when I can, but I do know my limits. As far as shafts, I used to have to straighten shafts after the screws were machined into them. The biggest where 8" inches in diameter, and 15' long. They were used for raising and lowering missiles on some kind of ship. Maximum out of round was .002" +/- over the full length. A massive cage went over these long screws. :)
Awesome, well it sounds like you are the right person for advice on this. I added bearing tolerances for the shortened steering shaft based on reference books - i.e. what is "typically" used for different fits based on the behavior needed. Keeping in mind these are for the tapered roller bearings like what you would get from allballs, I used a location clearance at h6 for the top bearing which should just slide on but keep the stem accurately centered, and a p6 interference fit for the lower bearing which gets pressed on. Though I'm not sure if I should drop the lower bearing tolerance down to a k6.

The tolerance on a 30mm ID metric taper bearing is meant to be 0 to -12um. Based on your experience are these likely to be appropriate tolerances for the stem?
 

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The bottom bearing is the most important bearing. The top one keeps the whole datum line (plane?) centered, and nice and tight for steering. I think you will be all fine. Nice thing about tapered head bearings is a little snug, and they are fine. As long as the inner races are firmly mounted and don't move, you're all set, IMHO It's not like your using ball bearings! . ;)
 

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Discussion Starter · #13 ·
The bottom bearing is the most important bearing. The top one keeps the whole datum line (plane?) centered, and nice and tight for steering. I think you will be all fine. Nice thing about tapered head bearings is a little snug, and they are fine. As long as the inner races are firmly mounted and don't move, you're all set, IMHO It's not like your using ball bearings! . ;)
Thanks for the feedback. I'll commit to getting the part made this week so will see how it goes...
 

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Discussion Starter · #14 ·
So this is a quick and dirty concept for the battery box and electrics configuration so far. Trying to keep it all looking as OEM as possible while making everything fit is challenging on this bike as its quite small. Its looking like there should be enough space to keep a standard J1772 charge cable under the seat with this layout. The old fuel tank will also house the 12V battery, m.unit and a few other smaller bits.
Cylinder Gas Font Auto part Machine
 

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Very nice, but to be honest, I would be primarily concerned with getting as many batteries in there as you can, as low as possible. The looks is great, but form follows function, and range is the ultimate goal. I think the Hub motor at the rear was a smart choice, especially as it weighs similar to the stock rim. I rode with a Verlorex Sidecar for around 7 years. I always though that if I made an electric bike, the side car would be perfect for more batteries. You could still carry a passenger, but if the sidecar is on you right hand side, then the extra weight would make taking hard right hand turns easier, as empty sidecars tend to lift very quickly. It took 10 minutes to mount my side car, as the bracked lined up perfectly (once it is initially is set up) and around 5 minutes to take it off. You could make a side car unit that pops off, leave it to charge, and continue on your motorcycle. Just a thought. I was able to ride in 8 inches of snow with that rig. :)
 

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Discussion Starter · #17 ·
Very nice, but to be honest, I would be primarily concerned with getting as many batteries in there as you can, as low as possible. The looks is great, but form follows function, and range is the ultimate goal. I think the Hub motor at the rear was a smart choice, especially as it weighs similar to the stock rim. I rode with a Verlorex Sidecar for around 7 years. I always though that if I made an electric bike, the side car would be perfect for more batteries. You could still carry a passenger, but if the sidecar is on you right hand side, then the extra weight would make taking hard right hand turns easier, as empty sidecars tend to lift very quickly. It took 10 minutes to mount my side car, as the bracked lined up perfectly (once it is initially is set up) and around 5 minutes to take it off. You could make a side car unit that pops off, leave it to charge, and continue on your motorcycle. Just a thought. I was able to ride in 8 inches of snow with that rig. :)
agree - But the charger, motor controller and other electrics also need to be on board within the boundary of the frame and bodywork.
The battery has been sized through calculation and should give a known/expected range that meets the targets I'm working to. A fair bit of excel modelling has been done in this area as part of my solar car work, and I adapted that calculation sheet for this build. The model was validated using matlab simulations so - while it is a simplification - it should give some fairly close estimates of what can be expected real world. ~8kWh should give just under 100km range at 100kph continuous using some very conservative rolling resistance, frontal area and drag coefficients that are typical of motorcycles. The range increases substantially at lower speeds. Of course It'll be an interesting exercise to validate this...

A sidecar for batteries is an interesting concept too. You'd certainly boost the range with that approach, but your drag would also be notably higher at highway speeds relative to using just a larger bike to begin with.
 

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You would be surprised just how low you can make a side car. All the way from side by side camper models, to wedges with one person almost laying down. The toe in and lean angle can (and should be) adjusted to the crown of the road. I could push my Suzuki at the tail light and the bike tracked perfectly straight. Below is a pic of the side car I had for 7 years and have regretted selling ever since. ;)

This was the only picture I could find of the exact one I had. I did machine a Titanium axle for it. The Windshield was much shorter than this one. Probably half the height. The amount of weight you could carry with a sidecar would be exponential to it's size and weight, to the overall vehicle. I carried a 5 Gallon tank of Gas in the trunk of my side car. This weight was good for the handling, and almost doubled my fuel capacity. With a battery pack that is larger than you could on your motorcycle, a flush deck platform would give your vehicle up to double the range, if not more, and a streamlined seat, 30 degree windscreen, and a very small body for the side car to carry a passenger. Just throwing some ideas out. ;)
Wheel Tire Fuel tank Vehicle Automotive lighting


These show the range that people go with side cars:
The first pic is, well awesome, though not my cup of tea, unless I had very very deep pockets:
Tire Wheel Car Land vehicle Vehicle


The flush deck utilitarian sidecar's wind resistance is based on what you put on it. A flat battery pack would be negligible:

Tire Wheel Vehicle Plant Ecoregion
 

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Discussion Starter · #19 ·
You would be surprised just how low you can make a side car. All the way from side by side camper models, to wedges with one person almost laying down. The toe in and lean angle can (and should be) adjusted to the crown of the road. I could push my Suzuki at the tail light and the bike tracked perfectly straight. Below is a pic of the side car I had for 7 years and have regretted selling ever since. ;)

This was the only picture I could find of the exact one I had. I did machine a Titanium axle for it. The Windshield was much shorter than this one. Probably half the height. The amount of weight you could carry with a sidecar would be exponential to it's size and weight, to the overall vehicle. I carried a 5 Gallon tank of Gas in the trunk of my side car. This weight was good for the handling, and almost doubled my fuel capacity. With a battery pack that is larger than you could on your motorcycle, a flush deck platform would give your vehicle up to double the range, if not more, and a streamlined seat, 30 degree windscreen, and a very small body for the side car to carry a passenger. Just throwing some ideas out. ;)


These show the range that people go with side cars:
The first pic is, well awesome, though not my cup of tea, unless I had very very deep pockets:


The flush deck utilitarian sidecar's wind resistance is based on what you put on it. A flat battery pack would be negligible:
Interesting concept. Running the numbers through the energy model shows the potential for a significant range drop unless the sidecar is designed using CFD to minimse drag. At highway speeds the increase in frontal area can completely negate the extra power on board making it a zero gain expense. That said at lower speeds (around 60-80kph) you would definitely increase range. Its a pretty challenging problem to solve.
 

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This is not a recommendation (most I can do with CAD at this point is to download the software). More of a 'make aware of' message. Anyway, a lot of my 'interweb friends' started using Solidworks, when the Experimental Aircraft Association worked a deal where members could get a slightly crippled version for free. After that deal expired, many of them switched to FreeCAD. Completely free, and IIRC, there's an FEA program available (also free) that can be fed FreeCAD files. It does run wholly on your PC (unlike Fusion 360, etc), and it isn't supposed to take massive computer or graphics card power to work well. I've watched a lot of instructional videos on it, and while it does have some 'features' that can bite if you're not aware, but problem areas seem to be only one of the ways you can do a particular thing, and other methods of achieving the same thing are built in, and pretty well documented by users.

FWIW....

Looking forward to seeing the electric bike build. Be sure to to include motor source, controller source, etc. If it's over 50 HP, I've got a light aircraft that could use something similar.
 
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