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Originally Posted by TexasElectric
Some other things i'm thinking about...
After reading a lot of different articles online about eBike speeds and watts, and watching a bunch of YouTube videos of people scientifically testing their eBikes I've decided I want to do the same. For example...
1. I've seen similar build eBikes use 400-450w to maintain 20mph. This would mean I could hypothetically get 61-68 miles on a full charge at an average speed of 20mph (assuming minimal wind and relatively flat roads). I am curious to know how many watts will be used at 25mph and 30mph (or even 35mph)? Plus I need to test watts used for pure electric vs pedal assist.
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My ebike used 25-34 wh/mile over a trip with me doing 25-28MPH and mainly only pedal assisting when accelerating (you'll likely have to change the gearing to be able to pedal at top speed). Your battery is about 1400-1500wh, 35wh/mi would give you a range of about 40 miles.
Quote:
Originally Posted by TexasElectric
2. I plan to use the tires that came on the bike (29x2.1) knobby tires until they are bald. Once they are ready to be replaced, I am looking to replace them with a 700x35, 700x40, or 29x1.5 non-knobby tire. The idea being that I'd have less rotational mass and rolling resistance but still have good contact with the ground. Plus (in theory) a smaller/smoother tire should use less watts to maintain speed.
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How smooth are the roads you'll be riding? 30MPH on a hardtail can be hard on the backside. Do some research about the skinny tires, I believe I've read that the "logically" best route of skinny and high pressure isn't necessarily the lowest rolling resistance.
Quote:
Originally Posted by TexasElectric
3. Lastly, I'm giving consideration to buying a few more LiFePo4 cells for 16s,7p for a total of 38.5 amp hours. The total weight of the battery with the addition of 2 additional cells in parallel would be 36lbs (compared to my current setup at 27lbs). If the addition of 2 more cells in parallel would allow me to ride at an average speed of 30mph (for my ride of 35 miles, one way), i'd consider it. But, i'll make this decision after doing a bunch of testing.
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Going to 6p or even sticking with 5p might be good enough, as I figured above. It comes down to just how much power your setup actually ends up using, how much you're willing to push the batteries, and how much cushion you want to have to account for headwinds or days that you don't pedal much.
For a charger, check out the Cycle Satiator. It's expensive, but you're certainly getting what you pay for. You could take it with you to charge at work and not have to worry about it falling apart like most chargers.