chas58 said:
Keep in mind that the ebike.ca simulator tested the Q100 a long long time ago. There have been changes to it since then, and the efficiency numbers may have significantly. We know the Q100H and Q128 are a lot different then they were back in those days.
I know that they have, and I know that the Q128C is an improvement over the Q100, but, at least according to the model, the Bafang CST is even more efficient than the eZee or MAC, and they're both more efficient than the Q100. The efficiency gains of the Bafang CST over the Q100 are worth more than even an extra ten pounds. I wish that I had current data now, but I don't.
I'm game to pitch in if folks would like to buy a Q128C (328rpm?) for ebikes.ca to characterize.
chas58 said:
For controllers: "torque simulating" controllers modify the current, the older design controllers are roughly like a throttle to limit power (i.e. speed limiting, but often use full current below max speed).
So of pswpower's torque simulating controllers, they have a
17A/350W and a
20A/500W spec'd at 36V/48V, and they're listed with both the same dimensions and weight. Any reason not to get the 500W? (Efficiency penalty?) They would work with either the Q128C or the Bafang CST, right?
(Their
12A &
15A are listed as 24V/36V.)
chas58 said:
Rather than soldering the shunts, I would rather get a controller with the current I need, and then dial it back with the PAS settings. But again, your graphs showed 10 amp usage. If you are willing to sweat, you don't need a lot of current. The current is mostly going to get you low end torque anyway. Do you need that? The high current does not help you at all with speed - if you are traditionally to the right of the inflection point.
Translating the batteries that I'm carrying into a "power budget," I can only afford to average 750W, tops, so I can't afford to 20A+ constantly. I plan on running 10A with up to 20A on steeper or longer ascents.
chas58 said:
Personally I think a gravel bike is the best solution 32-45mm tires, (long, low, slack geometry) with alternates being a cross bike (more agile) or a touring bike. Gravel/Cross are built rather like a cross country mountain bike, but with more road geometry.
The huge FalconEV triangle bag came in, and even though all the batteries fit in the bag, they don't fit on the bike, so the CAAD4's out of the running.
I agree with your general assessment of frame types. I went to look at the only seemingly good candidate on Craigslist on Sunday afternoon, but it was no good. Wrong time of year to be shopping.
In the meantime, I think that I'm going to repurpose a ~1993 Giordana with a 3/2.5 titanium (Litespeed) frame and an aluminum fork. It has enough clearance to fit a 28mm tire both front and back. I don't want to read too much into this, but it does have a nipple on the headtube for a frame pump and mounting eyelets above the rear axle for a rack or mudguards; still, its very much a racing bike. I'll keep my eye out for a better candidate.