tyrion wrote:As a fellow San Diegan considering a Mac motor from cell_man, I really enjoyed reading this thread. Thanks Joe for documenting your thinking, decision, and build.
I'm thinking of going with the 10T and frame battery as well. Also on a Giant (although older model) hardtail mountain bike. I don't have many hills on my commute but there are certainly a bunch around San Diego and I'd like to be able to ride around without having to fear them.
A few questions (if you're still following things):
Could you update on how everything is running after a full summer of use?
It's been just absolutely fabulous. The old AmpedBikes system always felt anemic and underpowered, popped fuses at least once a week, and blew the BMS twice. The Cell_Man system, by comparison, has been 100% reliable. The CA3 firmware had a few bumps along the way during the beta phase, but it has now reached a good level of stability, and the closed-loop current mode throttle works wonderfully (eg: push the throttle to 50% of travel, and you get 50% of rated current regardless of speed or incline.)
All in all, the system is working exactly as I'd hoped.
What kinds of top speeds are you seeing (without pedaling)?
I have no idea, as I always pedal. With average effort, I can easily cruise at 25 MPH on level ground, climb moderate inclines at 20 MPH with heavy pedaling effort, and my top speed downhill so far has been 36 MPH.
What size is your frame?
It's a "Large" in Giant's terminology, whatever that translates to in the real world. I'm no bicycle expect. I am about 6'2", and this frame is probably a tad smaller than would be recommended for me, but I've always preferred smaller vehicles, be they cars, motorcycles or bikes.
Anything you wish you had done differently? Different battery? Motor? Full suspension? etc...
The motor is just fabulous for my needs. The battery has also been great. If there were a choice to have it wired for 20S4P instead of 16S5P, I might be tempted to go for the extra voltage, but this is honestly a trivial point. Stepping up from an anemic 36v battery to this rugged 52v powerhouse was the difference between night and day.
As to full-suspension... When I first started frame shopping for this bike, I was leaning in that direction mostly because I thought it looked cool. But there are two major factors weighing against it. Battery fitment is one, and the other is that a rear suspension tends to soak up some of your pedaling effort, resulting in reduced efficiency. And having a hard-tail hasn't really been bothersome. In part, this is probably because I tend to stick to pavement and very well-maintained trails (mostly pedestrian walking paths between housing developments and office parks.) I'm not running especially fat tires, either. Given the choice between a rear suspension and having the perfect place to hide a large battery, I'll gladly give up the suspension. It's just not needed for a commuter bike.
The concept of "average" requires that 50% of the population be below it.