Secret1511
100 W
http://www.rohloff.de/en/products/speedhub/
Is this strong enough???
Is this strong enough???
Rohloff SPEEDHUB 500/14 (for mid drive)
- Thread starter Secret1511
- Start date
snoopshomme86
10 W
What type of motor will you use?
I think if you run it before the reduction it will work
I think if you run it before the reduction it will work
John in CR
100 TW
I thought the Netherlands was all flat. Why spend so much on multi-speed gearing you don't need or are you thinking more for your pedal input too?
The Rohloff is the best, so that's what you want, and yes it would stand up to a low power motor.
The Rohloff is the best, so that's what you want, and yes it would stand up to a low power motor.
BlackStridaAustria
1 mW
Does it help to know that the maximum input torque is 100 Nm?
Page 17 of the manual:
http://www.rohloff.de/uploads/media/1_General_use_En_2013_07.pdf
Page 17 of the manual:
http://www.rohloff.de/uploads/media/1_General_use_En_2013_07.pdf
snoopshomme86
10 W
this is what i meaned
if you run it at the first stage there will never be 100nm,
i m tes5ing an alfine at the moment and its running good too.
But if you runnit in last stage -in the rearwheel for example it could be a proplem at higher power levels
if you run it at the first stage there will never be 100nm,
i m tes5ing an alfine at the moment and its running good too.
But if you runnit in last stage -in the rearwheel for example it could be a proplem at higher power levels
Chalo
100 TW
What snoopshomme86 said.
A Rohloff Speedhub is ideal if it is the jackshaft in a mid-drive. Using it in the rear wheel and then feeding superhuman power into it is risking problems. It's rated for tandems, so if you limit the input torque to within spec and keep your power level to the range of what two very strong riders can produce (say 1000W continuous), then it should be fine.
But if you, like many others around here, want to make several kW of power and feed it through the hub, then put the hub in the middle where it can run at a much higher speed than normal, and use a reduction between the gearhub and the rear wheel. That would have the further advantage of saving wear on the relatively expensive Rohloff input sprocket.
When you overload a derailleur-based transmission, it wears out very quickly. But when you overload a gearhub, it can break completely and beyond repair.
For what it's worth, the old-style N171 NuVinci CVT hub is good for several kW of power, even when used in a full-sized wheel. It's much heavier than the Rohloff, but it does not have gear teeth to break off.
I have used a Rohloff hub for many years now, with 205mm cranks and my own body weight reaching 180kg during some of that time. I use 44/16 gearing, but the implied input torque when standing on the pedals was at least 130Nm. The hub has always worked faultlessly, but it is difficult to shift under heavy pedal load.
A Rohloff Speedhub is ideal if it is the jackshaft in a mid-drive. Using it in the rear wheel and then feeding superhuman power into it is risking problems. It's rated for tandems, so if you limit the input torque to within spec and keep your power level to the range of what two very strong riders can produce (say 1000W continuous), then it should be fine.
But if you, like many others around here, want to make several kW of power and feed it through the hub, then put the hub in the middle where it can run at a much higher speed than normal, and use a reduction between the gearhub and the rear wheel. That would have the further advantage of saving wear on the relatively expensive Rohloff input sprocket.
When you overload a derailleur-based transmission, it wears out very quickly. But when you overload a gearhub, it can break completely and beyond repair.
For what it's worth, the old-style N171 NuVinci CVT hub is good for several kW of power, even when used in a full-sized wheel. It's much heavier than the Rohloff, but it does not have gear teeth to break off.
I have used a Rohloff hub for many years now, with 205mm cranks and my own body weight reaching 180kg during some of that time. I use 44/16 gearing, but the implied input torque when standing on the pedals was at least 130Nm. The hub has always worked faultlessly, but it is difficult to shift under heavy pedal load.
Secret1511
100 W
Thanks all for the info.
Yess it's flat around here. I use my bike on mtb trails so i need some power.
I just wear out a chain and stuff so i was thinking is there a other system.
But to much power will tear it apart. But how much is 100nm? How much kw is that?
Yess it's flat around here. I use my bike on mtb trails so i need some power.
I just wear out a chain and stuff so i was thinking is there a other system.
But to much power will tear it apart. But how much is 100nm? How much kw is that?
Chalo
100 TW
Secret1511 said:
To put it in perspective: Assuming the Rohloff hub's specified minimum input gearing of 38/16, then you'd subject the hub to a torque of 100Nm if you pushed a 175mm crank with a force of about 138kgf. That's just torque and not power, as Miles points out.
speedmd
10 MW
Last time I checked the rolhloff was some $1400.00. That is $400 more than I have total in my build. A solid three or five speed will cover it well and not be a hassle to find the right gear. Still searching. :?
Chalo
100 TW
speedmd said:
The Rohloff Speedhub isn't just more expensive than other gearhubs. And it's not only the wider gear range that makes it different, either. It is much stronger, has much lower internal friction loss, and has uniform step size between all gears (which in practice reduces the hassle of finding the right gear, because the ratio change up or down is always the same).
I think it's easy to decide that a Rohloff isn't worth the high cost. I would never have gotten one for myself and one for my wife If I had been on my current budget. But no other gearhub or derailleur system does a comparable job.
crossbreak
1 MW
You may get one for €1000 shipped. A used one for half of that if you are lucky. I always use this formular, since it feel comfortable:
Power[kW]= Torque [Nm]*speed[rpm]/9550
speed at the input spocket is 3x85rpm=255rpm for example. 85rpm crank speed, 3x overdrive from cranks to the hub
Torque is 100Nm max.
So max power is 100*255/9555=2.67kW for that case.
If used in a Jackshaft, overdrive from cranks to the hub may be larger, for example 5x, since you can use a 5/3 reduction to the rear wheel. Then power would be 4.45kW.
Still you have to know the max torque of the motor using the motor constant and phase current (too lazy to explain that either).
Your question is something to relegate to the wiki. Yet I did not write an article about how to calc max motor torque, but I will do this some time.
Power[kW]= Torque [Nm]*speed[rpm]/9550
speed at the input spocket is 3x85rpm=255rpm for example. 85rpm crank speed, 3x overdrive from cranks to the hub
Torque is 100Nm max.
So max power is 100*255/9555=2.67kW for that case.
If used in a Jackshaft, overdrive from cranks to the hub may be larger, for example 5x, since you can use a 5/3 reduction to the rear wheel. Then power would be 4.45kW.
Still you have to know the max torque of the motor using the motor constant and phase current (too lazy to explain that either).
Your question is something to relegate to the wiki. Yet I did not write an article about how to calc max motor torque, but I will do this some time.
speedmd
10 MW
Yes todays x rate, that is $1326 US dollars. LBS Was quoting around $1400 last I checked. Will keep looking.
Bike Xing
1 W
- Joined
- Jun 5, 2013
- Messages
- 58
I have bikes with Nuvinci N360's. I am pretty rough on them with respect to terrain but my motor is only throwing another ~60 N*m max at it.
When kept within specified limits they are great though. Shifting through most of the range with one twist is amazing. Never listening to pops and clicks of derailleurs is great.
On one bike I pushed that to 75 N*m and the Nuvinci started barfing oil.
For my next off road bike I'd like to try a Rohloff. I like the weight difference and they look to be more reliable.
When kept within specified limits they are great though. Shifting through most of the range with one twist is amazing. Never listening to pops and clicks of derailleurs is great.
On one bike I pushed that to 75 N*m and the Nuvinci started barfing oil.
For my next off road bike I'd like to try a Rohloff. I like the weight difference and they look to be more reliable.
Jackrabbit
100 W
Both my brother and I run 2.5kw through Rohloff speedhubs with zero issues.
Secret1511
100 W
Jackrabbit said:
Nice!!! But can it hold 4 a 5 kw?
speedmd
10 MW
Its only 1000 euro, why not just buy a few and let us know. 
If it holds up to 5kw it is most likely worth the money. 
If it holds up to 5kw it is most likely worth the money. 
speedmd
10 MW
Opti is still listing their high powered model at 48v / 1100 watts with lower performance claims than I am getting on my GNG 1 setup! Is anyone putting 5kw or more into one? If so, I may rethink this.
speedmd
10 MW
I am sure it is more powerful as I see many good reports on their performance. But not a super performing bike.
If some are putting 5kw directly in through a speed hub, with the right torque limiting, it may be viable with much more power for a reasonable amount of time.
If some are putting 5kw directly in through a speed hub, with the right torque limiting, it may be viable with much more power for a reasonable amount of time.
dontsendbubbamail
10 kW
- Joined
- May 28, 2008
- Messages
- 718
Secret1511 said:
I don't think you are going to get an absolute answer. You might ask yourself, can I afford the cost and time to experiment or should I go with a proven design? Some of the folks here with more aggressive ridding styles can wear out/break equipment in a day that would last other folks for years.
Bubba
Chalo
100 TW
Bike Xing said:
A Shimano Nexus hub would be spitting teeth at a kW.
Bike Xing said:
Hm, i thought they eliminated anything like a standard model. When i visited them, i just saw the 850s and 1100's, both with rohloff hubs on 'em. I remember it distinctly since some kind of clutch/gear would slam every time you applied the power hard, due to their shitty controller spitting out large torque spikes every time you even moderately twisted the throttle from 0..
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