zer0zg
New member
- Local time
- 8:03 AM
- Joined
- Mar 2, 2022
- Messages
- 9
Hello all,
I'm in the design process for an art bike build for burning man. I but I have some questions regarding battery/motor choice that will impact some of the basic bike design decisions I need to make, so I figured I'd ask the experts here.
For background, I'm an aerospace engineer by education, and do quite a bit of fabrication on the side, so I'm not particularly afraid of pretty custom solutions(ie building a pack from scratch.
So the basic idea is I want to build a bit of a lowrider bike with a massive dirt track tire in the back, something like the image below. Tire is 29x15, and will be mounted on 15x12 car wheel. Current plan is for that wheel to mount to a car trailer hub, with a custom frame going to a pretty standard bicycle front end. Speed is definitely not the goal here, but range becomes pretty important given the overall weight of the bike will likely be ~70-80 lbs, and running out of power far from camp will be a long, hot hike. I can't see needing to clear more than 10mph, but 10-15 miles a day would not be unexpected(event is ~1wk). Some decisions to make as follows:
Motor: Leading plan is to keep it simple with 300-500W hub motor in the front. Unfortunately, I can't picture a way this does not preclude me from installing pedals up front, short of mounting a bottom bracket on the fork above the wheel, which somewhat kill the look and likely not be comfortable to use anyway. I'm willing to forego pedal backup, but it does put more pressure on the motor/battery solution being dialed. Curious to get input on wattage tradeoffs given my goals, as well as pack voltage.
Another option would be a chain/sprocket solution on the back wheel, but given the depth of the wheel and the car based nature of it, certainly complicates the rear end fabrication quite a bit. This would allow me to install a unicycle front end, and keep the pedal backup though. Also my suspicion is that the hub motor will be more dust proof(a real concern in this desert)
Battery: Again, leading plan is to go with an off the shelf ebike conversion kit, with a couple of spare batteries, ie buy 2-3 20Ah 36-48v batteries. Keep one on the bike, one spare carried and one charging at all times and call it a day. I do plan on having a solar generator/panels in camp, and could also run a generator/car inverter periodically to charge them.
The other option would be to build a larger pack. Currently leaning against this for a couple of reasons, first, it would make charging trickier, as I would want to be using the bike during daytime hours. Second, I live on the east coast and this whole rig will need to be shipped to Reno, and while I'm comfortable building/using a big battery in an open space, shipping a 30Ah+ lithium battery I built myself is slightly concerning. Happy to be proven wrong by those here though.
Other factors: it would be great to have USB out for lighting on the bike, I know some of the off the shelf batteries have this, and that is super convenient. Of course I could just have a separate battery bank for this, but just one more thing to charge. Durability is also pretty important here for the above mentioned reason, this is a pretty harsh environment.
Thanks guys
I'm in the design process for an art bike build for burning man. I but I have some questions regarding battery/motor choice that will impact some of the basic bike design decisions I need to make, so I figured I'd ask the experts here.
For background, I'm an aerospace engineer by education, and do quite a bit of fabrication on the side, so I'm not particularly afraid of pretty custom solutions(ie building a pack from scratch.
So the basic idea is I want to build a bit of a lowrider bike with a massive dirt track tire in the back, something like the image below. Tire is 29x15, and will be mounted on 15x12 car wheel. Current plan is for that wheel to mount to a car trailer hub, with a custom frame going to a pretty standard bicycle front end. Speed is definitely not the goal here, but range becomes pretty important given the overall weight of the bike will likely be ~70-80 lbs, and running out of power far from camp will be a long, hot hike. I can't see needing to clear more than 10mph, but 10-15 miles a day would not be unexpected(event is ~1wk). Some decisions to make as follows:
Motor: Leading plan is to keep it simple with 300-500W hub motor in the front. Unfortunately, I can't picture a way this does not preclude me from installing pedals up front, short of mounting a bottom bracket on the fork above the wheel, which somewhat kill the look and likely not be comfortable to use anyway. I'm willing to forego pedal backup, but it does put more pressure on the motor/battery solution being dialed. Curious to get input on wattage tradeoffs given my goals, as well as pack voltage.
Another option would be a chain/sprocket solution on the back wheel, but given the depth of the wheel and the car based nature of it, certainly complicates the rear end fabrication quite a bit. This would allow me to install a unicycle front end, and keep the pedal backup though. Also my suspicion is that the hub motor will be more dust proof(a real concern in this desert)
Battery: Again, leading plan is to go with an off the shelf ebike conversion kit, with a couple of spare batteries, ie buy 2-3 20Ah 36-48v batteries. Keep one on the bike, one spare carried and one charging at all times and call it a day. I do plan on having a solar generator/panels in camp, and could also run a generator/car inverter periodically to charge them.
The other option would be to build a larger pack. Currently leaning against this for a couple of reasons, first, it would make charging trickier, as I would want to be using the bike during daytime hours. Second, I live on the east coast and this whole rig will need to be shipped to Reno, and while I'm comfortable building/using a big battery in an open space, shipping a 30Ah+ lithium battery I built myself is slightly concerning. Happy to be proven wrong by those here though.
Other factors: it would be great to have USB out for lighting on the bike, I know some of the off the shelf batteries have this, and that is super convenient. Of course I could just have a separate battery bank for this, but just one more thing to charge. Durability is also pretty important here for the above mentioned reason, this is a pretty harsh environment.
Thanks guys