Brilliant Trex, it's good to see how these guys in Asia are doing such great job on hub and crank technology. I am not a great fan of the current crank motors, but no doubt they too will get better. It's currently my opinion that for most people a hub drive is the better option.

 

All the best, David

Edited August 24, 20169 yr by Wisper Bikes

I always suspected that the real pull of crank drive is high and illegal speed. (geared) hub motors are optimized for 15mph, so tend to lose most of their efficiency at over about 19mph while with a CD motor, you only have to trick the speedo and push the bike easily over 23mph without losing efficiency.

You are probably right Trex, I hadn't thought of that, it would be good to know how many illegal dongles have been sold in the UK.

 

No wonder Bosch don't put a bit of software in there making the bikes fail when a dongle is attached.

The GSM will easily pull 35 kmh on the flat at quite low Amps.

 

No wonder Bosch don't put a bit of software in there making the bikes fail when a dongle is attached.

 

The software isn't clever enough. It would be easy enough for them to limit top speed to 25 kmh dongle or no dongle. They have a GPS in the some of the displays already if I understand correctly?

Just a thought: all the clever programmers at Bosch were working on the VW software...

I always suspected that the real pull of crank drive is high and illegal speed.

 

Not for me.

 

I prefer to stay legal, and the pull for me, is the off road usability which I consider to be more of a complete and useable package when compared to that of hub drive.

 

This was actually something that I gave great consideration to during the recent Swiss Alps trip, and came to the conclusion that there was no way that I would have wanted a hub drive bike for the bulk of the climbing.

 

I have no idea how a hub drive would cope with say this ride that had an elevation gain of 6,428ft over a pretty much continuous climb of 10.4 miles. It would have tackled the first half with ease, but when the hard packed stone/scalping track became a rock garden for the remainder, I am certain that I'd have given up very soon after the seven mile point. I should also add that some sections were even impossible using a crank drive system. Loss of traction on the very loose surface being the limiting factor.

 

http://doarama.com/view/906954

 

 

I have always found that when using a rear wheel driven hub drive eMTB off road, the front end of the bike becomes too light and difficult to control over rocks and other tricky terrain, and the balance is completely wrong, which makes hopping over objects an impossibility. Make those objects several miles in length, and it would soon lead to misery and ride failure.

The other concern either imagined or real, is how long would it be before spokes break through endless bashing of the rear wheel when tackling rocky descents.

 

I'm not saying that hub drives eMTB's aren't brilliant fun to ride off road, because they are, and they certainly have their place, and indeed do have a few plus points over crank drive, but when conditions worsen, I firmly believe that crank drive is the right type of power system to choose.

 

edit.. I do have a contradiction with myself, as I am currently in the process of planning a rather unique hub drive trials ebike using an Orange Zero. For all of the above perceived negatives, I still really love and rate them.

Edited August 24, 20169 yr by EddiePJ

i take it you dont want a bomber bike then @55kg yes it will go fast, fast going down DH tracks then forget it its to heavy you be on ur ass most of the time.

Not for me.

 

I prefer to stay legal, and the pull for me, is the off road usability which I consider to be more of a complete and useable package when compared to that of hub drive.

 

This was actually something that I gave great consideration to during the recent Swiss Alps trip, and came to the conclusion that there was no way that I would have wanted a hub drive bike for the bulk of the climbing.

 

I have no idea how a hub drive would cope with say this ride that had an elevation gain of 6,428ft over a pretty much continuous climb of 10.4 miles. It would have tackled the first half with ease, but when the hard packed stone/scalping track became a rock garden for the remainder, I am certain that I'd have given up very soon after the seven mile point. I should also add that some sections were even impossible using a crank drive system. Loss of traction on the very loose surface being the limiting factor.

 

http://doarama.com/view/906954

 

 

I have always found that when using a rear wheel driven hub drive eMTB off road, the front end of the bike becomes too light and difficult to control over rocks and other tricky terrain, and the balance is completely wrong, which makes hopping over objects an impossibility. Make those objects several miles in length, and it would soon lead to misery and ride failure.

The other concern either imagined or real, is how long would it be before spokes break through endless bashing of the rear wheel when tackling rocky descents.

 

I'm not saying that hub drives eMTB's aren't brilliant fun to ride off road, because they are, and they certainly have their place, and indeed do have a few plus points over crank drive, but when conditions worsen, I firmly believe that crank drive is the right type of power system to choose.

 

edit.. I do have a contradiction with myself, as I am currently in the process of planning a rather unique hub drive trials ebike using an Orange Zero. For all of the above perceived negatives, I still really love and rate them.

 

I agree Eddie, for off road, very steep terrain and for hopping over rocks and roots, basically mountain biking, a Bosch mid motor system is ideal.

 

All the best, David

possibly. I would say a BBS02 36V 25A is a good deal more flexible.

Mid Drive is better for climbing. Pedals equal more RPM's than Tire giving you more torque @ lower rpm's. I have a Stromer rear gear-less drive drive which is great on road. Under 7mph the motor whines and torque is gone.

Mid Drive is better for climbing. Pedals equal more RPM's than Tire giving you more torque @ lower rpm's. I have a Stromer rear gear-less drive drive which is great on road. Under 7mph the motor whines and torque is gone.

Mid-drive is better for climbing than what and which mid drive are you talking about?

A Bosch drive is better than a Stromer on steep hills. It's better than the Wisper on very steep hills. The Wisper would beat a Sunstar mid-drive on very steep hills. My Xiongda hub-motor trumps all of them.

 

You have to be careful with general statements because there's a lot of different motor systems.

I'm with d8veh, depends on the hill in question. Now that I have a few 100 km under my belt I would say different not better.

 

Hill climbing is all about gearing so I would say that the Giant bikes with double chainwheel and Yamaha motor would probably be better in my conditions than the Bosch.

 

My Mxus with 34 tooth granny gear would climb walls, or at least ramps over 20%, I tried it. I tried the same with the GSM and failed (i.e. stopped well before things could go wrong).

You have said it yourself.

 

You have to be careful with general statements because there's a lot of different motor systems.

 

Also there are lots of different terrain and conditions to use said motor systems.

 

My Xiongda hub-motor trumps all of them.

 

You make the same mistake as you have accused Cip57, in the very same post.

 

Your set up would fail in the steep rocky terrain of the Alps, and would potentially be a complete pain in backside on many of the places and conditions that I ride. Just like any hub drive would.

 

Equally though, hub drives can be so much more fun off road if the conditions and terrain are correct for their use. I'd say that hub drives off road have given me more smiles in the way that they deliver the power, but the main reason that I love them, is the way that rear hub drive motors seemingly unload the front end of the bike and make it very light, this is brilliant fun in the right and safe conditions. I also like the way that in at least the two that I have owned, that they allow you a little cheat in relation to crossing smaller puddles or terrain where you can't get a full pedal stroke. On swift push before the section, is usually enough to give the motor an extra second or so of power to get through or across.

 

The downsides of hub drive in off road use easily out weigh the plus points though.

 

Downsides for me are..

 

• Poor weight distribution
  
• Poor off road handling due to weight distribution
  
• Unsprung weight
  
• Heavy rear end which makes hopping over obstacles impossible, and would make rocky ascents all but impossible.
  
• Potential overheating on arduous lengthy climbs.
  
• More hassle to remove the rear wheel, and yet another spanner to carry.
  
• Cabling which could have potential to become caught up
  
• Greater spoke or even possibly rear hub failure when tackling jumps, or when descending rocky terrain.
  
• Greater potential for water ingress when tackling deep water filled ruts
  
• The light front end which I love is would also be potentially dangerous when trying to attempt rock gardens or very steep climbs
  

 

I do like hub drives enough though, that my Orange Zero trials bike build is more than likely to going to use one, over the choice of crank drive.

But that is being built for a very specific use, where speed is always likely to be just walking pace, any drops are going to be very slow and controlled, with landings onto soft terrain. I also want that light front end, and the more compact motor design and less bulk that a crank drive has. The hub drive system also has zero crash impact risk from hitting anything hard within the crank area.

 

So both systems in my opinion have advantages and disadvantages, laziness of ride and I'm guessing lack of complexity, must be a couple of the hub drives greatest plus points.

 

 

.

Edited September 20, 20169 yr by EddiePJ

http://derestricted.com/enduro/my-first-professional-ebike-race

You make the same mistake as you have accused Cip57, in the very same post.

 

Your set up would fail in the steep rocky terrain of the Alps, and would potentially be a complete pain in backside on many of the places and conditions that I ride. Just like any hub drive would.

 

I don't think I have made a mistake. The Xiongda has immense torque- much more than a Bosch in bottom gear. It's torque is also very controllable though either current control (PAS), speed control (throttle) or a combination of both. It's not a very heavy motor at about 3kg. Downhill, the weight at the rear helps and uphill you get better traction, and most important of all, it doesn't matter what gear you use, because its torque is independent.

 

Ultimately both systems provide torque to the back wheel, so why do you think a hub motor would be a pain?

I have fully explained my reasons above, look at the bullet points. You don't appear to be offering any reasons why a hub drive is better in a proper off road technical situation.

 

As I stated both motor systems have their place, but crank drive is always going to be better off road on tough technical terrain and climbs. For the bulk of users who want to ride bridleways and highways, a hub drive makes a lot of sense. That I can't even begin to dispute, and would even state that they are more fun, and pleasurable to ride.

 

Funny that you now also refer to torque as the important factor, when just yesterday you stated that torque was of no importance, and that it was gearing that counted.

 

Torque doesn't mean anything. It only depends on the gearing, which can be easily changed.

 

So which is it?

 

 

 

 

 

.

Edited September 20, 20169 yr by EddiePJ

Happily another great thread!

 

I think what in essence is being said is there are a multitude of uses for an e-bicycle which is compounded by the fitness of the rider and the terrain the bike will be used on. There is enough choice now and market forces will make certain the perfect ebike will be available, one to fit any set of criteria. A bike does not exist that is all things to all people so don't try and find it.

 

I think we all agree, the best way to choose is to go to a good ebike shop, listen to the advice from the professionals. Test ride all the bikes they offer, when you find the correct bike you will know. It isn't necessarily the most expensive in the shop!

 

Regards, David

Edited September 20, 20169 yr by Wisper Bikes

I have fully explained my reasons above, look at the bullet points. You don't appear to be offering any reasons why a hub drive is better in a proper off road technical situation.

 

As I stated both motor systems have their place, but crank drive is always going to be better off road on tough technical terrain and climbs. For the bulk of users who want to ride bridleways and highways, a hub drive makes a lot of sense. That I can't even begin to dispute, and would even state that they are more fun, and pleasurable to ride.

 

Funny that you now also refer to torque as the important factor, when just yesterday you stated that torque was of no importance, and that it was gearing that counted.

 

 

 

So which is it?

The problem is that you've taken that quote out of context. I used it when talking about the torque figures that manufacturers state for their CD bikes, like Bosch is 60 Nm and Yamaha is 70Nm makes it sound like the Yamaha is more powerful; however, the Yamaha might have lower power, but it gets it's torque with lower gearing and lower speed.

 

The only thing that makes a difference is the actual torque at the back wheel whatever gear you're in. The Xiongda motor has an internal low gear, so it makes very high torque directly in the wheel no matter which gear you're in. It can change to a higher internal gear, which roughly doubles the speed and halves the torque, so it can give you speed and torque like a CD motor, but it runs at higher power than a Bosch or Yamaha, so it makes more torque at the same speed as them.

 

 

 

 

 

.

Just out of interest Dave, what is the opinion about the motor on this set up. Ignoring the bikes design with it's very scary looking shock position, the hub design appears to look very robustly built?

 

The drop out design caught my eye in relation to your latest build project.

 

Full suspension. http://www.cheetah.de/e-bike/e-bike-mountainspirit.html

 

Hardtail. http://www.cheetah.de/e-bike/e-bike-forpleasure.html

 

I really love the look of the hardtail, and those clean lines are what I'm aiming at for the Orange Zero project. For that though I'll be looking at the smallest possible motor and battery combination that I can get away with.

 

 

.

Edited September 20, 20169 yr by EddiePJ

Does the Xiongda motor fail if you push the bike backwards? Are there any reliability based concerns? Does it take a cassette or freewheel? How is it for building a strong rear wheel that is properly aligned. All questions I have seen directed at rear hub motors.

Just out of interest Dave, what is the opinion about the motor on this set up. Ignoring the bikes design with it's very scary looking shock position, the hub design appears to look very robustly built?

 

The drop out design caught my eye in relation to your latest build project.

 

Full suspension. http://www.cheetah.de/e-bike/e-bike-mountainspirit.html

 

Hardtail. http://www.cheetah.de/e-bike/e-bike-forpleasure.html

 

I really love the look of the hardtail, and those clean lines are what I'm aiming at for the Orange Zero project. For that though I'll be looking at the smallest possible motor and battery combination that I can get away with.

 

 

.

It's difficult to know without knowing the speed of the motor winding (KV). I would guess that it can be reprogrammed for 45 km/h, so might be a bit weak on low speed torque and efficiency. It doesn't say the voltage. If only 36v, it'll probably not be as good as a KTM Panasonic, which has 48v. That's all just a guess, though.

 

One other thing. Rear suspension doesn't work very well with a heavy motor in it because the ratio of unsprung to sprung mass is too low. That's one area where crank-drives do get an advantage.

Does the Xiongda motor fail if you push the bike backwards? Are there any reliability based concerns? Does it take a cassette or freewheel? How is it for building a strong rear wheel that is properly aligned. All questions I have seen directed at rear hub motors.

I push mine backwards every day and it's still going strong, so no. The only failures I know have been on recumbents or similar, where people paddle them backwards with a lot of force and weight on the motor. It's not a problem on a bicycle because there's not enough weight on the wheel, which would skid if the motor locked.

 

Mine has done 4000 miles and isn't showing any signs of wear, even with my weight on it. I guess it will run on to over 20,000 miles. Time will tell. I guess that there's not a lot of people that would do 4000 miles on an electric bike.

 

The hub has 36 holes in it. You can build it as straight or strong as you want. Mine's straight, strong and completely maintenance free. I don't really understand your question.

 

It's a freewheel motor. I got round the low top gear problem by using a DNP freewheel, which is showing no signs of wear after 4000 miles.

"The hub has 36 holes in it. You can build it as straight or strong as you want. Mine's straight, strong and completely maintenance free. I don't really understand your question."

It was more a question of can you get sufficient dish on the drive side in particular and still have the rim centred in the frame.

Bikes with Bosch, Panasonic, Kalkhoff and Brose motors all have special frames to mount the motor. If an OEM wanted to use a Xiongda motor, or any similar motor, they should also have a special frame with a suitable offset. I modified my rear subframe so that the rim sits centrally without a dish. Self-builders don't normally have access to frame modifications, which means they have to compromise by dishing wheels. Unfortunately many people involved in the supply chain of ebikes haven't got a clue, so I'm not surprised to see dished wheels on OEM bikes, which are completely unnecessary.