new to e bikes advise please

[geoff c]

hi
new to e bikes which bike should I buy crank or hub drive, I am 5ft 7 15 stone with a 29in inside leg live in hilly lakedistrict want a bike that can get me to work 6mile round trip and for week end rides. have tried a batribike step through (did not like) would like to spend no more than 850 pounds many thanks

 

[Deleted member 4366]

I don't see much choice with that budget: The Woosh Big Bear or any one of their crank-drives. I think I'd go for the Big Bear.

 

[geoff c]

I don't see much choice with that budget: The Woosh Big Bear or any one of their crank-drives. I think I'd go for the Big Bear.

don't really want to spend how about 1,000 pounds any idea

 

[trex]

geoff, you need big motor for hills + your weight, big motor needs big battery.
The next price up is the Ezee Torq Mk3. That will be around £1400.

You can't get a German bike with big motor and big battery for less than £1500 (Kalkhoff Xion 24).

The cheapest big motor + big battery is the £850 Woosh Big Bear:

We've been over this situation once a week.

 

[geoff c]

thanks I will have to save up a bit more is crank drive better

 

[trex]

...is crank drive better?

No, not when you are heavy. Crank drives excel on speed (if you derestrict your bike), a big hub motor gives you better torque and acceleration up to about 20mph (if you derestrict your bike) and are better at traffic lights.

 

[JuicyBike]

We have just a few 2013 Sports left at our website only at £885, which might interest you...

 

[Cyclezee]

Hi Geoff,

Having been brought up near Penrith on the edge of the Lake District I know all about the hills that you are talking about.

Just inside your budget is the eZee Sprint Primo shown here on our website http://cyclezee.com/ezee-sprint-primo.html

eZee Sprint Primo £850​

Trex mentioned the eZee Torq above in his post, this can be a be £120 cheaper by opting for the lower capacity 11Ah battery.


The same applies to the Sprint 8 and Forza

eZee Sprint 8​

eZee Forza RWD​

Forza review on YouTube​

 

[D8ve]

A crank drive is better on hills especially with the larger cyclist.
Don't try to save money by buying a smaller battery. Save up longer or buy the whoosh.
Good luck and welcome

 

[Deleted member 4366]

A crank drive is better on hills

Which crank-drive is better than what and why do you think that?

When I tried a crank-drive on the test hill at the last Presteigne show, it was the only bike that couldn't get me up the hill. I guess I'm a larger rider at 100kg.

 

[D8ve]

d8veh

especially If a bike is restricted to 250 watts. The gearing in a crank drive gives you the option of maintaining a higher motor speed to remain efficiently driving the bike. A hub motor can slow stall and enter the highly inefficient zone providing little drive and overheatIng the motor.
I accept that some hubs can run at higher ratings but they can also end up being inefficient with a larger rider on steep hill.
Ergo cranks are better on hills.
Hubs may well be cheaper and cost effective on flat to gentle hills.

 

[trex]

but reality is, the 250W is only nominal (on paper). All quality bikes pump out more than double that while climbing hills. You may call it cheating but that's reality though. The only thing that stop BPM size crank drives is the chain. 7/8 speed chains are strong enough for about 500W (true output), the NuVinci can't take more than 350W-400W, while hub-driven bikes with a BPM can easily peak at 600-700W. BPM bikes are very effective for up to 10% gradient and will propel 150kg riders up 10% slope.

 

[D8ve]

Unfortunately there are a a number of hills around here that hit 20% such as pope walk. Extreme I know but they exist. This is when gearing stops the magic smoke leaking

 

[Deleted member 4366]

d8veh

especially If a bike is restricted to 250 watts. The gearing in a crank drive gives you the option of maintaining a higher motor speed to remain efficiently driving the bike. A hub motor can slow stall and enter the highly inefficient zone providing little drive and overheatIng the motor.
I accept that some hubs can run at higher ratings but they can also end up being inefficient with a larger rider on steep hill.
Ergo cranks are better on hills.
Hubs may well be cheaper and cost effective on flat to gentle hills.

Sorry, but that's absolute ball-cocks, You're trying to make a general statement based on a limited unrepresentative sample. You need to get out and try some modern hub-motors. On that test in the German magazine, the Panasonic one (250w) not only out-climbed the Bosch, but it was more efficient. When your motor stalls out on a steep climb, my 250w Xiongda will still be purring happily. It can get my 100kg up a 30% hill with a bit of help from me. You can design a hub-motor run at any speed at high efficiency.Climbing ability has nothing to do with the type of motor.

All motors can run at higher speed to remain efficient, but when climbing, you need torque. You don't get high torque and high efficiency. To get the torque, you need the motor to slow down into its inefficient zone. It's the same whether you have a motor driving the crank or the wheel.

 

[D8ve]

D8veh
Yes it is a generalised statement. You can design a motor to be efficient at almost any speed. But not stalled. If a motor is stalled or near stall. Little motive force is produced. High current flows and overheated motors happen.
My Panasonic crank drive climed steep hills around bath. Converting current into motion very well. It had help from me yes but it climbed well. Few hub drives will run slowly and efficiently and fast and efficient.
I concede that a hub drive can be cheaper but not always as efficient but we are arguing over finer points of performance. Can we be civilised about it please.

 

[trex]

this case is borderline. We're restricted to legal road bikes, that rules out kits like the BBS02 36V 25A because they are labelled 350W or 500W.
If the rider was lighter (13st), I'd say crank drive is the obvious choice for the Lake District, you can climb much steeper hills (15% - 20% on motor power). But at 15st, raw grunt of a BPM ( all big powerful motors, such as ezee, Xion, not just 8-Fun BPM) is more useful on 97-98% of routes, up to 12% gradient, for the remaining 2-3%, get off the bike and use the 6mph walk mode or pedal very hard. The xiongda XD would do very well but it still falls short of what is ideal for the Lake District and does not have the grunt of a BPM.

 

[Deleted member 4366]

D8veh

Few hub drives will run slowly and efficiently and fast and efficient.

When you say "few hub-motors", how many crank-motors are there in the shops? - Bosch, Impulse, TMC, Panasonic. The good climbing legal hub-motors are: Falco, Bafang BPM, Bafang CST, Heinzmann, Panasonic, Xiongda, Ezee, Dapu. Have you tried any of them? I hope you can come to the Bristol event in June or the Woosh one at Redbridge in August. I'll bring my Xiongda for you to try. I think you'll then change your mind about which type of motor climbs best.

If a motor is stalled or near stall. Little motive force is produced. High current flows and overheated motors happen.

That's true, but it's just as true whether you have a crank-drive or hub-motor.

I concede that a hub drive can be cheaper but not always as efficient

Hub-motors have exactly the same efficiency as the motors in crank-drives- somewhere around 80% except Falco claim efficiency of 90% for their 5-phase hub-motor.

The xiongda XD would do very well but it still falls short of what is ideal for the Lake District and does not have the grunt of a BPM.

The Xiongda runs happily at 20 amps, which is still legal. It won't out-climb a 180rpm BPM at 20 amps, but it's just as good as a 250rpm one at 22 amps. The Woosh Big Bear only has 15 amps. I'm guessing that it's 201rpm. I haven't tried them back to back, but I'm pretty sure that the Xiongda would win. It would be perfect for the Lake District. It dragged me up a 30% hill, slower than Saneagle on his 30 amp BPM, but with less pedal force. he was panting when he got to the top. I was just breathing heavily.

 

[Arbol]

Very interesting discussion.

d8veh, you do not include xofo either among the good climbing hubs or the crank drives. Is there a specific reason for that?

 

[trex]

...
The Woosh Big Bear only has 15 amps. I'm guessing that it's 201rpm. I haven't tried them back to back, but I'm pretty sure that the Xiongda would win. It would be perfect for the Lake District. It dragged me up a 30% hill, slower than Saneagle on his 30 amp BPM, but with less pedal force. he was panting when he got to the top. I was just breathing heavily.

Woosh told me that they've run out of stock on the Big Bear and they've upped the Amps on the Big Bear ( by changing the BMS) on the next delivery end of this month. The BPM on the Big Bear is wound for 230 RPM.

 

[Deleted member 4366]

Very interesting discussion.

d8veh, you do not include xofo either among the good climbing hubs or the crank drives. Is there a specific reason for that?

Yes, because I've not yet seen one with a 250w label even though they're available as OEM. It's a clone of the Bafang and there's also the MXUS clone, which I haven't tried. The Xofo has the power of the Bafang 500CST, but is slightly lower RPM, so climbs better.