logoalt Hacker News

selfhoster1312today at 7:09 AM3 repliesview on HN

I was shocked by the price, too. I mean a motor and a battery can't be so expensive, especially such a "small" battery (300Wh).

That being said, having driven electric bikes for a while, here in France they're ridiculously limited in speed and power. 25km/h limit on flat land usually makes sense (except on long straight lines), but when you get climbing even slightly you get down to ~10km/h and have to provide more effort. I guess that's where the 750/1250W 70Nm unrestrained motor comes in handy, and if you live in a place with lots of small hills the choice is either that kind of motor or a car, not the 1000€-total Decathlon/Carrefour electric bike.


Replies

RugnirVikingtoday at 10:35 AM

> a motor and a battery can't be so expensive

In my experience with electric motors, yeah I can absolutely believe it. Electric motors aren't cheap!

show 1 reply
bramblerosetoday at 7:25 AM

In my experience the issue is one of torque, not of power. Most cheaper electric bicycles (including most Decathlon models) have a hub-mounted motor which cannot deliver power effectively at low speeds -> it stops assisting when you most need it. For hilly terrain you need a motor that's mounted on the crankshaft so that it can take advantage of the gears.

To compare: a tour de france runner outputs 400-500W on mountain climbs while keeping up to 20-25km/h. So a 500W motor (plus 100W power output from yourself) should be enough for smaller climbs!

show 1 reply
bendewstoday at 8:41 AM

I have a heap of ebikes, all 250w and 25km/h limited. A Bosch performance line motor on a MTB going up a steep hill is effortless compared to a budget shimano motor where it can barely make it up no matter how much effort you put in to pedalling. Torque makes a big difference.

show 1 reply