How good is the Big Bear on hills?

[safetyfast]

Evening all,

A friend of mine is considering a Big Bear after I made him aware of Woosh bikes. We are in rural mid Devon and it is quite varied, hilly terrain. I have BBS01 crank drive on my bike.

By all accounts the Big Bear is pretty powerful and copes with hills well. Just wondering what experiences are with mixed terrain. I considered a Big Bear myself so would be intrigued to see how one performs.

Cheers,
Paul

 

[Deleted member 4366]

The Big Bear will be a lot faster on moderate hills than your BBS01. It's generally a lot more powerful than your motor. Maybe if your hills got to about 25% or more, which is fairly extreme, your one might have a chance against it in bottom gear with a lot of effort from you.

 

[trex]

very good for up to about 12% gradient. The crank driven Krieger climbs a bit better.

 

[flatbat]

very good for up to about 12% gradient. The crank driven Krieger climbs a bit better.

25% or 12%?

 

[flecc]

25% or 12%?

Like any crank drive e-bike, on either, but only in the sense of capability. On most hills the crank drive will be slower climbing than a high power hub motor e-bike like the Big Bear, since the crank drive climb advantage is gained by using the motor through lower gears. The difference between crank and powerful hub motor evens out as the steepness increases.

If your hills are never steeper than 14% and mostly up to 12%, a powerful hub motor e-bike like the Big Bear will give better average speeds.

If you have many hills from 14% upwards in steepness, you may well prefer the crank drive overall.
.

 

[flatbat]

Like any crank drive e-bike, on either, but only in the sense of capability. On most hills the crank drive will be slower climbing than a high power hub motor e-bike like the Big Bear, since the crank drive climb advantage is gained by using the motor through lower gears. The difference between crank and powerful hub motor evens out as the steepness increases.

If your hills are never steeper than 14% and mostly up to 12%, a powerful hub motor e-bike like the Big Bear will give better average speeds.
.

I do actually "get it". It was the precision of the gradient percentages that prompted my comment as there is an immense difference between 12% and 25%. Seems that 12% to 14% is it then?

 

[mike killay]

Which all goes to support my suspicion that the two speed hub motor is the way forward.
Advantages,
1 Not trying to put power through a gear system designed for lighter loads.
2 No need for the expensive and complicated torque sensor system to switch off the motor when changing gear.

 

[flecc]

Seems that 12% to 14% is it then?

That's my experience from years in a hilly area with both a crank drive bike and two powerful hub motor e-bikes.

But the personal factor makes a big difference. A powerful rider who can keep a hub motor e-bike up to it's optimum climb speed on a given slope can move that gradient step much higher. Conversely a weaker rider can find the hinge point lower at 10% or less.

These can also be affected by some crank drives software if they demand a high proportion of rider input to their torque sensors to give enough motor input for a climb. Once again that can swing things in favour of the powerful hub motor over a greater range of gradients.
.

 

[trex]

25% or 12%?

I am not heavy and can just about climb 20% gradient with the Krieger on first gear with pedalling.
The motor on the Krieger is as powerful as the Big Bear, both are powered by the same eletronics (20A Lishui LS947), the use of the gears gives the Krieger just that bit extra where you can choose speed over torque or vice versa.
I like very much the concept of the double-speed Xiongda XD but what is needed to beat both the Big Bear and the Krieger is the 180mm version of the XD. I don't know if or when Xiongda release it.

 

[selrahc1992]

Like any crank drive e-bike, on either, but only in the sense of capability. On most hills the crank drive will be slower climbing than a high power hub motor e-bike like the Big Bear, since the crank drive climb advantage is gained by using the motor through lower gears. The difference between crank and powerful hub motor evens out as the steepness increases.

If your hills are never steeper than 14% and mostly up to 12%, a powerful hub motor e-bike like the Big Bear will give better average speeds.

If you have many hills from 14% upwards in steepness, you may well prefer the crank drive overall.
.

This is exactly what I found. I've got a 250w hub motor and a friend a 250w crank drive and we travel on mixed terrain,one VERY steep hill and a few long gradual ones. Unless your friend weighs well over 100kg I think a hub drive may be average faster and perhaps lower maintenance,and a BPM overkill

 

[Geebee]

Just for the record and newbies, the above only applies assuming reasonable rider input, if you have limited input from the rider a hub will fail to climb hills that the crank drive in low will climb with ease, albeit slowly.

 

[Deleted member 4366]

Just for the record and newbies, the above only applies assuming reasonable rider input, if you have limited input from the rider a hub will fail to climb hills that the crank drive in low will climb with ease, albeit slowly.

I'm afraid that's not true at all. It's nothing to do with the type of motor. It's possible to pull you up a vertical wall with a hub-motor.

Have you tried a Xiongda, an old 28 amp Heinzmann, a KTM Panasonic, or even a Bafang BPM at 20 amps or more?

 

[trex]

yes, I have tried all of the above and I still prefer crank drives over hub drives. My favourite CD bike so far is the Kalkhoff with Panasonic motor.

 

[Geebee]

I'm afraid that's not true at all. It's nothing to do with the type of motor. It's possible to pull you up a vertical wall with a hub-motor.

Have you tried a Xiongda, an old 28 amp Heinzmann, a KTM Panasonic, or even a Bafang BPM at 20 amps or more?

I was assuming a legal setup, as per the discussion.

 

[Deleted member 4366]

I was assuming a legal setup, as per the discussion.

All those motors are legal.

 

[Benjahmin]

To answer the original question:
We live in hilly West Wales. My wife's Big Bear LS climbs ALL the hills around here, where her previous Giant Esprit would have her off and walking. She is around 65Kg, slightly less in years and no athlete. Battery range is good, we haven't managed to run it flat yet, latest round very hilly trip of 25 miles. It is slightly under geared for flat riding, comfortable cadence topping out at about 20-22 mph.
The ezee motors are just as capable, as my own conversion attests.

 

[Geebee]

All those motors are legal.

Surprising!, but as a guide an Ezee wont come close to a Crank drive for climbing ability if un-assisted, I have tested on the same hill locally and it wasn't one of the steeper ones. I have also tried a 1kw rated 2 kw peak DD hub but that was useless on steep hills with out a lot of assist as well (obviously illegal).

 

[Deleted member 4366]

You need to try a few more hub-motors motors. You can't judge them all by trying just a few. The direct drive motor you tried probably had a high speed winding for fast cruising, which is why it wouldn't climb. If you had one that was wound for 25km/h max, the legal speed limit, it would probably have wheelied all the way up the hill.

 

[Benjahmin]

Though I am a rapidly ageing old git, I still want to put in some effort . If what's wanted is engine only climbing ability then I think a motor bike is the answer. Both the Big Bear and ezee Mk2 are very able at doing their job, ASSISTING.
That's why they're called EAPC's.
Safetyfast:
In June, we'll be coming through Devon to holiday in Cornwall, with both our bikes. If you'd like to try them PM me and we'll try to make a hook up.
Ben

 

[Geebee]

Though I am a rapidly ageing old git, I still want to put in some effort . If what's wanted is engine only climbing ability then I think a motor bike is the answer. Both the Big Bear and ezee Mk2 are very able at doing their job, ASSISTING.
That's why they're called EAPC's.
Safetyfast:
In June, we'll be coming through Devon to holiday in Cornwall, with both our bikes. If you'd like to try them PM me and we'll try to make a hook up.
Ben

I agree completely and was a keen cyclist for many years, unfortunately my state of health no longer allows more than token pedalling but I enjoying taking a bike out occasionally still but also live in a very steep enviroment.
I was just stating that if a reader had a similar requirement in my experience a CD was ideal.

d8veh, I have a 500w rated 20 kph top speed DD hub running at 36v and 30 amps and it can't climb upto my house without assistance, although it is brushed.