Question I couldn't answer ...

[danfoto]

Here's what a hub motor can do up a long 30% hill. Show me a crank drive that can do this:
https://www.youtube.com/watch?v=RIHJPOL3_HQ

Sorry, but I'm not familiar with the bike. I can see it's got a hub motor in the back, but is that bike legal on UK roads?

Ooops - just seen that my question's already been answered.

 

[Deleted member 4366]

The motor's a MAC motor that's very similar to the Bafang BPM that several forum members have.

.........and another point, Indalo: We have members of this forum from many different countries where completely different regulations apply and the OP never put any boundaries in his OP.

 

[Eaglerider]

For consistent steep hill climbing, like off road, climbing the South Downs, my preference would be a Bosch crankdrive, probably de-restricted. I have ridden a Panasonic crank drive, but found it pretty weedy.

For everything else, I'd take my 250 watt hub drive, it provides more power all the time, and is a far more capable tourer, being generous with its power, and I live in a pretty hilly area. It also provides the option to ride without any pedalling at all, which is part of the 'magic sensation' of e-biking.

I find the crank drives are more like ordinary unpowered bicycles, but with some assistance, wheras my Eagle takes me on quiet, relaxing cruises through the countryside, with just a gesture of pedalling at 17 to 18 mph, and it's bl**dy great.

 

[flecc]

I think that's a very fair and accurate description of the differences Eaglerider.

The latest Panasonics are much more like the Bosch units now though.

 

[Kudoscycles]

I think its all about fitness and speed. I took a customer out on a test ride last week on our normal route along the promenade and up the hill. We both pedalled along side by side on the promenade without a puff-he was intrigued by the auto button which allows 4 mph without pedalling.
We were both on identical Kudos Tourer bikes with Nexus 8 hubs. At the hill I went down to second gear,he tore away from me in 4th gear-he was probably fitter than me but not by much. So we both tried the hill again,this time I stayed in 4th gear-I found that as long as I kept the speed above 8mph,the motor was working well and I was putting in less effort.
In conclusion if you are able to maintain 8mph in any circumstance-uphills,along the flat,against head winds then hub drive is very good. But if you spend your cycling in any circumstance that you are not able to maintain the magic 8 mph because of lack of fitness or constantly tackling steep hills then crank drive is best.
If only we could put another gear into the hub to allow that magic speed to be reduced to say 4 mph and then use lower gears on the bikes gearing I would suggest that crank drive would be unnecessary in 99% of circustances.
The not insignificant point that nice hub drive bikes are available at £1k,whereas the favoured crank drive machines are usually £2k plus.
Dave
KudosCycles

 

[danfoto]

It also provides the option to ride without any pedalling at all, which is part of the 'magic sensation' of e-biking.

For some. It certainly isn't as far as I'm concerned, but to each his own

 

[flecc]

If only we could put another gear into the hub to allow that magic speed to be reduced to say 4 mph and then use lower gears on the bikes gearing I would suggest that crank drive would be unnecessary in 99% of circustances.

Almost there Dave, the new SRAM rear hub motor has two integral motor gears to do just that. Unfortunately it's only a single rider gear at present, width problem of course, but that might be solved. One could have a triple chainring with it to give three rider gears, and maybe adapt a Schlumpf two speed bottom bracket to the tripkle rings and have six rider gears.

If we get the latest recommended removal of power limits passed into EU law, hub motors will definitely make things very difficult for crank drives.

 

[mike killay]

For consistent steep hill climbing, like off road, climbing the South Downs, my preference would be a Bosch crankdrive, probably de-restricted. I have ridden a Panasonic crank drive, but found it pretty weedy.

For everything else, I'd take my 250 watt hub drive, it provides more power all the time, and is a far more capable tourer, being generous with its power, and I live in a pretty hilly area. It also provides the option to ride without any pedalling at all, which is part of the 'magic sensation' of e-biking.

I find the crank drives are more like ordinary unpowered bicycles, but with some assistance, wheras my Eagle takes me on quiet, relaxing cruises through the countryside, with just a gesture of pedalling at 17 to 18 mph, and it's bl**dy great.

Sorry to keep banging on about the Tonaro but they are totally different to Panasonic and Bosch. There is no torque sensing at all, twist the throttle as far as you like and in comes the power without any artificial restriction. Add this the fact that you can change the gear of the motor and I think you have the best system you could want.

 

[flecc]

Yes, the Tonaro is like the Cyclone "crank" motors, throttle controlled, but all crank drives use the bike's gears of course.

But Eaglerider is still correct about hub motors, they mostly have more power and so in most circumstances are better performers.
.

 

[Kudoscycles]

Flecc,do you have any further references to the SRAM hub motor with 2 internal gear sets (I think I have understood your posting correctly?), I personally am very pleased with the Nexus 8 internal hub system in the rear-it seems very well developed by Shimano and has such simplicity over derailleur systems. So I would like to mount a 2 speed geared hub motor in the front wheel,is this possible?
Or is there a better setup?
Dave
KudosCycles

 

[Deleted member 4366]

IIRC Justin on ES demonstrated a two speed hub gear. It changed into the lower gear by rotating backwards. I think this idea has neen around for a while - just waiting for it to find its way into mass-production.

 

[flecc]

Flecc,do you have any further references to the SRAM hub motor with 2 internal gear sets (I think I have understood your posting correctly?), I personally am very pleased with the Nexus 8 internal hub system in the rear-it seems very well developed by Shimano and has such simplicity over derailleur systems. So I would like to mount a 2 speed geared hub motor in the front wheel,is this possible?
Or is there a better setup?
Dave
KudosCycles

No reason why it couldn't be done with a front hub motor Dave, but it would mean rather wide forks.

Here's a link to that two speed hub announcement:

SRAM 2 speed hub motor

 

[Kudoscycles]

Flecc,putting the controller in as well do you not think is just making it too complex,but auto switching at say 8 mph should be easily achievable? Do you think it would freewheel? Would it have to be bigger diameter to accomodate the second set of gearing? Thanks for the reference,looks like 2013 production.
This doesn't seem difficult engineering,surprising that it has taken so long for the industry to wake up to 2-speed hub motors.
Do you see any downsides?
Dave
KudosCycles

 

[flecc]

I'm fairly sure it will freewheel Dave, since with it's simplicity in operation it's obviously aimed at the utility market. Integrating the controller has big advantages if reliability is high, no different from crank drives where they are also integrated and generally more reliable than hub motor controllers.

It will be half speed gear changing I'm sure, about 8 to 10 mph.

The diameter isn't bigger but the width is a problem since it's two speed gears are probably alongside the motor and it's normal hub motor reduction gearing. Certainly it looks as though it occupies almost the whole width of that 135 mm dropout, which is why it's only got the one rear sprocket and rider gear. That's one downside of course, limiting it to utility use where cyclists aren't bothered about pedalling all the time. The other downside is that this might compromise it's use in pedelec only markets since the one gear would have to be high enough to pedal with moderate cadences at 15 mph, leaving the gear a bit too high for hill climbing, putting most of the responsibility for that on the motor.
.

 

[Kudoscycles]

Flecc,but if the motor was in the front wheel surely the rider gearing would be independent in the rear. I see this as a big marketing advantage-the bike would be identical whether you used single or duo speed hub motor,the only change would be the front hub motor. If you spend most of your riding on the flat then single speed would be ok,unfit or hill climbing then specify the duo speed. The on cost with volume production would be small.It would make crank drive pretty much an expensive overengineered product.
Dave
KudosCycles

 

[andyh2]

There's a few forks for 135mm hubs on the 'fatbike' scene eg the Surly Pugsley or Moonlander forks. Designed to take wide tyres, 3.7" for Pugsely, 4.7" for Moonlander, but more importantly should be able to take the SRAM 2 speed hub motor. That would leave the rear free for gearing of choice. It will be really interesting to see how good the SRAM is and how much it costs of course!

For rear placement it would be really great if they found a way to integrate the 2 speed automatic hub with the 2 speed electric hub, but that seems unlikely in the space available.

 

[flecc]

Flecc,but if the motor was in the front wheel surely the rider gearing would be independent in the rear. I see this as a big marketing advantage-the bike would be identical whether you used single or duo speed hub motor,the only change would be the front hub motor. If you spend most of your riding on the flat then single speed would be ok,unfit or hill climbing then specify the duo speed. The on cost with volume production would be small.It would make crank drive pretty much an expensive overengineered product.
Dave
KudosCycles

True Dave, and I'd rather have it that way. The only disadvantage though is the very large and presumably heavy 2 speed front hub. Of course freedom from power limits if it comes could almost kill off both the two speed hub and crank drives.

 

[Kudoscycles]

Flecc,I have no idea of the weight of the SRAM duo motor. With regard to freedom of power limits I thought that was already a dead duck....we still have not signed up to EN15194-when requested why not from our government I got a letter by return that was full of so much ministerial gobblygook that Humphrey off Yes Minister would have been proud of. So the chances of us approving any higher power limits are pretty much nil,aren't the sports cycle lobby against it anyway.Also politically we seem,rightfully in my opinion,to be resistant to any further regulation from Europe.
The test Xenion 650 I have at work is very precise in it's power delivery making it particularly good for slow speed off road usage. I see this 2 speed hub to be ideal for someone who only rides on tarmac but needs to ride slowly up hills,using similar rider gearing selectionto a non assisted bike but with help.
Dave
KudosCycles

 

[flecc]

Our best hope for the limit freedom is the delay of the DfT in waiting for Europe's latest rulings before cleaning up our own legislative mess. Given how long the DfT take to do anything, the limit removal may be part of the finalised EU laws by then. But of course, our usual excessive nanny state instincts may kick in and block parts of any benefits.

I agree the two speed hub is only suited to road use, and I'm sure more for the utility/shopper market than anything else. There it's simplicity of operation and lack of owner technical involvement is ideal, just charge and pedal with no manual gear changing. I'm guessing it's a bit heavy from it's visual size and it probably having two internal gear mountings etc.