Hello,
This is my first post on Endless Sphere. I've been reading and learning a lot from posts here and I thought it was time to share my first ebike build. To give a little background on myself, I am a former competitive cyclist who raced road, off road, and track (though never in danger of winning any of them) back in the '90's. I no longer race, am nearing 50, and live in a very hilly portion of Seattle. My riding now is taking my 8 yo daughter to and from school and some general commuting and running errands.
I own one of the very early Radwagons with the steel frame and have put a few thousand miles on it. Generally I've been quite happy with it. My daughter and I enjoy riding the bike together and I often find with Seattle's traffic I can get places faster on the bike than by driving. The only real issue I've had with the bike were loosening spokes on the rear wheel early on, but the Rad guys tuned and tightened them and they've stayed tight since then. I would also occasionally have to retighten the rear wheel bolts as they would loosen due to the power/regen cycles and no torque arm.
As much as I like the Radwagon, I am by nature a modifier and customizer, and thus decided to comprehensively upgrade the bike this winter. My goals are to have more power for getting up hills (there are some hills here in Seattle I can't pedal up with my daughter on the bike, even with the Radwagon on full power assist), more top speed for when I'm in a hurry or need to ride in traffic at speed for safety reasons, and to have a bike the feels good to ride. This last point means I want actual torque sensing and not just cadence sensing. One of my frustrations with the stock Radwagon is its lack of TS. To me, it makes the bike feel unresponsive and "flat".
I looked at mid drive setups, but after a lot of reading and research (a lot of it here of course) I decided I wanted to stick with the hub drive for simplicity, minimizing drivetrain stresses, and to keep regen braking. When I came across the Grin GMAC hub it seemed like a good fit for my needs. Enough power, regen braking, and integrated torque arm all fit the bill. So I specced out a 10T motor in a 26" wheel, Sempu TS bottom bracket, and Phaserunner with a 72v battery. With this combination I should have roughly 4x the torque of the stock Shengi motor on the RW, and a top speed of 35mph when I need it. I'll have throttle and the TS for true pedal assist.
I am a long term hot rodder and wanted this build to be clean and functional with minimal excess wiring or visual clutter. In researching batteries I found the Luna Cycles 72v 10AH fat triangle (https://lunacycle.com/72v-triangle-panasonic-GA-10-5ah/) which seemed like it would just fit in the rear triangle of the RW behind the seat tube. I knew if it didn't fit there, it would easily fit in the main triangle. So I ordered one up.
When the battery arrived I found it did just fit in the rear triangle. I could even still run the front derailleur if I wanted to, but I decided to simplify by going to a 1x10 drivetrain, so the derailleur was removed. The stock RW mounts its controller on two steel cross members above the rear triangle. I used those to mount the battery to the frame. I used a 0.25" thick aluminum plate that counter sunk allen head bolts into and adhered to the top of the battery using 3M 5200 marine sealant/adhesive (very strong stuff that doesn't let go EVER).
This is my first post on Endless Sphere. I've been reading and learning a lot from posts here and I thought it was time to share my first ebike build. To give a little background on myself, I am a former competitive cyclist who raced road, off road, and track (though never in danger of winning any of them) back in the '90's. I no longer race, am nearing 50, and live in a very hilly portion of Seattle. My riding now is taking my 8 yo daughter to and from school and some general commuting and running errands.
I own one of the very early Radwagons with the steel frame and have put a few thousand miles on it. Generally I've been quite happy with it. My daughter and I enjoy riding the bike together and I often find with Seattle's traffic I can get places faster on the bike than by driving. The only real issue I've had with the bike were loosening spokes on the rear wheel early on, but the Rad guys tuned and tightened them and they've stayed tight since then. I would also occasionally have to retighten the rear wheel bolts as they would loosen due to the power/regen cycles and no torque arm.
As much as I like the Radwagon, I am by nature a modifier and customizer, and thus decided to comprehensively upgrade the bike this winter. My goals are to have more power for getting up hills (there are some hills here in Seattle I can't pedal up with my daughter on the bike, even with the Radwagon on full power assist), more top speed for when I'm in a hurry or need to ride in traffic at speed for safety reasons, and to have a bike the feels good to ride. This last point means I want actual torque sensing and not just cadence sensing. One of my frustrations with the stock Radwagon is its lack of TS. To me, it makes the bike feel unresponsive and "flat".
I looked at mid drive setups, but after a lot of reading and research (a lot of it here of course) I decided I wanted to stick with the hub drive for simplicity, minimizing drivetrain stresses, and to keep regen braking. When I came across the Grin GMAC hub it seemed like a good fit for my needs. Enough power, regen braking, and integrated torque arm all fit the bill. So I specced out a 10T motor in a 26" wheel, Sempu TS bottom bracket, and Phaserunner with a 72v battery. With this combination I should have roughly 4x the torque of the stock Shengi motor on the RW, and a top speed of 35mph when I need it. I'll have throttle and the TS for true pedal assist.
I am a long term hot rodder and wanted this build to be clean and functional with minimal excess wiring or visual clutter. In researching batteries I found the Luna Cycles 72v 10AH fat triangle (https://lunacycle.com/72v-triangle-panasonic-GA-10-5ah/) which seemed like it would just fit in the rear triangle of the RW behind the seat tube. I knew if it didn't fit there, it would easily fit in the main triangle. So I ordered one up.
When the battery arrived I found it did just fit in the rear triangle. I could even still run the front derailleur if I wanted to, but I decided to simplify by going to a 1x10 drivetrain, so the derailleur was removed. The stock RW mounts its controller on two steel cross members above the rear triangle. I used those to mount the battery to the frame. I used a 0.25" thick aluminum plate that counter sunk allen head bolts into and adhered to the top of the battery using 3M 5200 marine sealant/adhesive (very strong stuff that doesn't let go EVER).