New member advice on new ebike please

[Woosh]

That graph reminds me how complicated motors are. It's a pity they can't operate with max power, torque and efficiency at all speeds. I know 2wd exists but has anyone ever paired two very different motors in a bike, one good at low speed and one good at high speed?

d8veh have made a few 2WDs. The crank drives are not as good at towing as the BPM. We do suggest a total weight limit of 110kgs on crank drives and recommend Big Bears for anyone heavier or towing.

 

[Deleted member 4366]

That graph reminds me how complicated motors are. It's a pity they can't operate with max power, torque and efficiency at all speeds. I know 2wd exists but has anyone ever paired two very different motors in a bike, one good at low speed and one good at high speed?

Yes, I did that with a 201 rpm MXUS motor in the front and a 328 rpm Q100 in the back. It worked pretty well with a heavy rider, but there's not much advantage over a single bigger motor in the back now that we have decent controllers that can adjust the power.

 

[Danidl]

That graph reminds me how complicated motors are. It's a pity they can't operate with max power, torque and efficiency at all speeds. I know 2wd exists but has anyone ever paired two very different motors in a bike, one good at low speed and one good at high speed?

.. they do it's called a crank drive.... Seriously that is what a gearbox does, it insures that the motor can be going at its most economic, efficient pace and can adjust the road speed to the appropriate speed. I don't think that ebikes with central drives need to have a huge number of gears however, a few say 3 to 5 should be enough, providing the spacing of ratios is sufficiently wide.

 

[PeterL]

Hopefully, the right place for this? Have now read many, if not most of the posts in an effort to bring myself up to speed with narrowing down the list of bikes to research in more detail.

I do like the look of the Kalkhoff
Kalkhoff Sahel Compact i 8
but, not the many adverse comments on here with regard to the motor. There again this thread started a long time ago. I wonder what the current thinking is?

Peter

 

[Deleted member 4366]

Do you feel lucky?

 

[1boris]

My bosch cx cut of on the same hill I burned my Xiongda 48volt hub motor.But the q128H 800w hubmotor made it at 48v 18 amp.It was actually less hot than my friends bbs02 48v 20a at the top.The q128 was in a 26" wheel and had a top speed about 43-44 kmh on the flat throttle only.fantastic motor So yes hub motors can climb.

 

[topographer]

I was thinking of something much more asymmetric like a Xiongda two-speed in one wheel and a big direct drive in the other, or a big DD paired with a BBS. But it wasn't really a serious question...I was just having a laugh.

 

[anotherkiwi]

Hopefully, the right place for this? Have now read many, if not most of the posts in an effort to bring myself up to speed with narrowing down the list of bikes to research in more detail.

I do like the look of the Kalkhoff
Kalkhoff Sahel Compact i 8
but, not the many adverse comments on here with regard to the motor. There again this thread started a long time ago. I wonder what the current thinking is?

Peter

The motor may work with the 20" wheels. I believe that it can't handle 700C wheels and low cadence.

 

[topographer]

My bosch cx cut of on the same hill I burned my Xiongda 48volt hub motor.But the q128H 800w hubmotor made it at 48v 18 amp.It was actually less hot than my friends bbs02 48v 20a at the top.The q128 was in a 26" wheel and had a top speed about 43-44 kmh on the flat throttle only.fantastic motor So yes hub motors can climb.

How steep is that hill?

 

[Woosh]

My bosch cx cut of on the same hill I burned my Xiongda 48volt hub motor.But the q128H 800w hubmotor made it at 48v 18 amp.It was actually less hot than my friends bbs02 48v 20a at the top.The q128 was in a 26" wheel and had a top speed about 43-44 kmh on the flat throttle only.fantastic motor So yes hub motors can climb.

hub motors seem to benefit greatly from better air flow around the motor.

 

[John_S]

Which are some of the crank drive models that have heat sensing software to protect the motor from overheating? I assume the Kalkhoff bikes do?

 

[Woosh]

all the German crank drive motors are protected.

 

[1boris]

How steep is that hill?

Its an offroad hill up to a mountain top here in Norway.the road is in bad condition some of the steepest places.lots of rolling resistance.and you need to lean forward for the front wheel not to lift at the steepest.but some small parts are almost flat.average maybe 10-15 %? No chance gertting up the steepest parts with my BH neo cross.no chance for a Bpm 250w 22amp bike or a woosh BPM ebike total trip is about 20 min.And of all the bikes I have tried the q128H 800w was the coolest at the top.the bosch cx overheated and had a safety cut out.

 

[topographer]

Its an offroad hill up to a mountain top here in Norway.the road is in bad condition some of the steepest places.lots of rolling resistance.and you need to lean forward for the front wheel not to lift at the steepest.but some small parts are almost flat.average maybe 10-15 %? No chance gertting up the steepest parts with my BH neo cross.no chance for a Bpm 250w 22amp bike or a woosh BPM ebike total trip is about 20 min.And of all the bikes I have tried the q128H 800w was the coolest at the top.the bosch cx overheated and had a safety cut out.

Thanks. It's nice to hear real world edge cases.

 

[PeterL]

The motor may work with the 20" wheels. I believe that it can't handle 700C wheels and low cadence.

Having listened

Anyone care to rank the following: 1-10? I appreciate that there is always an element of personal preference but I am getting close to a decision having probably over-thought much of this. Reading through the posts has been enlightening and I’ve eventually taken the over-riding (pun) advice to discount other than Bosch or Yamaha motors.

Winora Radius Urban

Orbea Katu E10

Tern Vektron Folding Bosch Electric Bike

Last but not least (if still available)

http://www.pedelecs.co.uk/forum/threads/riese-muller-blue-label-roadster-touring-for-sale.28790/

The last one has me a little worried about my knees and I believe the smaller bikes to offer a bit more security when it comes to stopping, for whatever reason?

Peter

 

[anotherkiwi]

I really like the first two, probably in that order, having seen both in the flesh. If I had the means I would probably buy a Winora. As I don't have that money I have plans for a home built Tern folder further down the line.

 

[Wisper Bikes]

If the Riese and Muller Roadster has sold, I have one showroom model left. I am open to sensible offers.

All the best, David

 

[PeterL]

If the Riese and Muller Roadster has sold, I have one showroom model left. I am open to sensible offers.

All the best, David

Thanks for the offer I will see how this pans out first ,as you'll have guessed the smaller bikes seem to have the most appeal - but only just the R&M does look the part.

Peter

 

[1boris]

hub motors seem to benefit greatly from better air flow around the motor.

Yes,if they are inrunners like the q128 motors not outrunners like most hub motors like BPM and others most others hub motors

 

[Kendalian]

Ive tried the Yamaha powered Winora - it only has 3 gears and I wasn't overly impressed. I've got the Katu e20 which has 8 gears and the Bosch Active line motor - very impressive. The e10 will be even better with the Bosch Performance CX motor and 500whr battery. Needless to say i'd go for the Katu!

Cheers

Kendalian