MadRhino said:
Don't be fooled. I am all hub, every bike I build is with a hub. Yet I feed my hubs 20+ Kw, that is a hundred times the one you are about to build. A 200w powered hub is good in a very small wheel, like mobility vehicles. In a bicycle wheel it is lame, and its weight is more of a nuisance than help. It is for a reason that EU regulations changed the market and almost all new ebikes sold in Europe are driving the chain.
With that low power only a mid drive can give you some interesting torque, because the use of the gears is giving you full range of transmission ratio. I always say: Mid drives are best at both ends of power builds. When you don't build enough power to make a hub alive, or when you build too much power to keep a hub alive.
Go ahead. Test ride both and see by yourself.
fyi from google
""
How much power can the average person generate?
A trained cyclist can produce about 400 watts of mechanical power for an hour or more, but adults of good average fitness average between 50 and 150 watts for an hour of vigorous exercise. A healthy well-fed laborer over the course of an 8-hour work shift can sustain an average output of about 75 watts."
So the poster is presumably familiar w/, & thinks the bike would almost do, even if pedaled. Well, that presumably is using the average ~150 watts now, but only for an hour, after which he is tired and hot. (as b4, on a test track, such bikes use 100w for 25kph, then 100w for each extra 5kph due to wind).
Apart from as little as 4kg extra, he now has the same only almost 100 watts more at 250w, sans pedaling.
yes he only has one gear, but adelaide and 30km, am pretty sure most is kinda 30kph, smooth riding. I would guess .5m folks if that, mild hills, v hot in summer, 1/4 acre block homes rather than condoS, well paved.
I suspect from some utube 200w hubs on the testbench vids, they are factory geared on a 700c wheel to a rpm that maxes out at ~33kph, so given they are more efficient at higher revs, around 30kph should work well w/o a headwind, which would suit him. He may have to pedal ASSIST to get rolling so as not to inefficiently tax the motor & battery too much. just pedal leisurely when it gets out of its comfort rpm range.
further, i actually have/had a 200w very heavy lead acid battery 24v ebike, gearing no comment - its low, but the power is certainly more than i could pedal. Its sufficient for many of my errands in mildly hilly terrain.
you dont seem to listen - its a sub 9kg bike, google it, mid drive or big hubs are simply unsuitable. on a different bike and budget, definitely the 1700$A mid drive MTB i suggested, but as the problem was stated, hubs are most consistent with a balanced solution.
I also think it not a bad solution, that others could emulate profitably - a really light (sub 15kg), eminently pedalable, drop bars, racing wheels. As above, 250w is far more than most can manage for an hour, so clearly, its to all intents a self powered equal to a racing bike, and they are damn fine machines for locomoting a human on the sniff of a fart.
The catch is, u cant economise on battery. u still need a good one on any bike. if it doent work for some reason, he will be stuck with an expensive battery that is too small for plan B, and would blow away any hoped for economies.
My other reservation, is that he is 90kg. a little high for a bike i would guess is rated at 110kg or less maximum load. with the bike, he would be 105kg.
Thats kinda why i lean a bit to the simplicity of a front hub. IF it dont work for him, fine, onsell the wheel & battery to someone it suits, and a child could swap bits over in an hour~ - no chain/cassette complications.
dunno, but a mid drive kit install sounds beyond a noob. swapping cranks sure sounds ambitious. Also heavy, dear and unsuited to a racing frame.
good suggestion re test rides tho. If u see a guy on one, slip him $10 for a test ride.
