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
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.
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.
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...)
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.
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.
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.
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
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.
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.
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...)
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.
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.
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.