I'm pretty happy with this build. As far as I know, it's the first of a kind, being a FWD MBB mid-drive recumbent. A friend of mine and I have built up a variety of 6 rear wheel hub motor CruzBikes (using front wheel hub motors), but I've been curious about mid drives, so we decided to split the cost of this experiment. On a CruzBike, a mid-drive has two additional disadvantages over the obvious rear hub motor setup: all the weight in the front triangle greatly reduces quick maneuverability, and the all-wheel-drive traction is lost. So even before we started we knew we'd be sacrificing the trail riding we regularly enjoy on our existing builds in exchange for efficiency on the road, high speed torque, and very stable steering.
The starting bike is one of the earliest frames by CruzBike and is long out of production. It's actually the very same bike that was used to prototype the first electric CruzBike before all the awesome hub kits and lithium batteries became easily available that we all love. By far, the most difficult part was removing the existing bottom bracket. I finally got it off with a giant crescent wrench while clamping the BB removal tool against the other side of the spindle with a huge C clamp
.
Once I got it together yesterday afternoon we rode it around a parking lot a few times, came back to the garage, fine tuned some things like the speedometer sensor and cabling, and then immediately went back out for some serious testing. I ended up riding 60 miles and climbing 4780 feet yesterday evening. This dropped 10.2V on a 17Ah 14s lithium ion battery charged to 58.4V. Unfortunately the Cycle Analyst 1.0 with that bike was not working, so I can only estimate the WH/m to be about 12. I've gotten better than this on the same ride with my two hub motor builds, but not at the minimal effort I put into pedaling this time! I'm looking forward to comparing the same ride against my Mac motor build with the same battery.
This morning I figured out how to lift the speed limit, and did some more testing and determined the top speed on flats is between 31 and 34 mph (depending on direction on the 3 stretches I tested on). This is with 26" wheels, 44t chain ring, and 11t cassette. I have a bit more to say on my first experience with a BBS02, but I'll save that for another post and finally get to the pictures:
The starting bike is one of the earliest frames by CruzBike and is long out of production. It's actually the very same bike that was used to prototype the first electric CruzBike before all the awesome hub kits and lithium batteries became easily available that we all love. By far, the most difficult part was removing the existing bottom bracket. I finally got it off with a giant crescent wrench while clamping the BB removal tool against the other side of the spindle with a huge C clamp
.Once I got it together yesterday afternoon we rode it around a parking lot a few times, came back to the garage, fine tuned some things like the speedometer sensor and cabling, and then immediately went back out for some serious testing. I ended up riding 60 miles and climbing 4780 feet yesterday evening. This dropped 10.2V on a 17Ah 14s lithium ion battery charged to 58.4V. Unfortunately the Cycle Analyst 1.0 with that bike was not working, so I can only estimate the WH/m to be about 12. I've gotten better than this on the same ride with my two hub motor builds, but not at the minimal effort I put into pedaling this time! I'm looking forward to comparing the same ride against my Mac motor build with the same battery.
This morning I figured out how to lift the speed limit, and did some more testing and determined the top speed on flats is between 31 and 34 mph (depending on direction on the 3 stretches I tested on). This is with 26" wheels, 44t chain ring, and 11t cassette. I have a bit more to say on my first experience with a BBS02, but I'll save that for another post and finally get to the pictures:
