# Various Internal Devices Efficiency.



## Johnny Chicken Bones (Jul 13, 2005)

This is probably already listed on a thread somewhere in here. 
Feel free to blame me or a not so great search tool. 
Eiher way- here it is again.

What's The Difference In Speed Between Gearbox Systems? Rohloff, Pinion, Shimano - CyclingAbout

I'm surprised these hubs are as efficient as this shows. 
And surprised that even some lower models do well.

I'd be curious to know how their efficiencies change over time. 
Perhaps an Alfine is close to a Rohloff at the start of its life. 
And maybe it has more drag later in its life? Or is that just me?

-JCB


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## fokof (Apr 24, 2006)

Wow thanx !

I would be curious to know the efficiency of a 1X12 drivetrain.
In fisrt and twelfth , there is a serious chain bent. ( energy loss)


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## Johnny Chicken Bones (Jul 13, 2005)

Fokof-
Funny you mention that. There's a new internal rear hub coming. 
Kindernay.
Seems like it could compete with Rohloff.

Kindernay - Kindernay
A friend is interested in it and is demoing a prototype. 
When I asked why internal had his interest (even though he's already tried such iterations years ago) he mentioned (among other things) harsh chainlines.

The 1x craze has allowed us to ignore things we used to think we're more important. 
When I ride behind someone with a 1x- you can sometimes really see that bend you're talking about.

There's a holy grail idea in my head about the perfect internal. 
Like it will never be found but I keep wanting it.

-JCBs


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## mikesee (Aug 25, 2003)

Good article. I too think it needs 1 x 11 and 1 x 12 comparisons added to be relevant today.

I'm very curious about the Kindernay. Rohloff's have never really been compelling, for a host of reasons. The simpler, cleaner look and form factor of the Kindernay, along with the hydraulic shifting mechanism and a thru-axle option kinda tie the room together.

Or so it seems on the surface. Only lots of riding will really show what's what.


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## fokof (Apr 24, 2006)

Johnny Chicken Bones said:


> Fokof-
> Funny you mention that. There's a new internal rear hub coming.
> Kindernay.
> Seems like it could compete with Rohloff.


http://forums.mtbr.com/internal-gear-hubs/new-light-weight-internal-gear-hub-kindernay-1025896.html


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## Ailuropoda (Dec 15, 2010)

I think people are missing something here. The extra drag may be negligible on paper but it's small forces that make most of the difference in cycling. Suppose you're going up a three percent grade. The vector component of yours and the bike's combined weight acting against you as a force might be very small (five pounds?) but it's enough to make a significant difference in the effort you need to expend to keep your speed up. I can fly effortlessly down a three percent grade spinning out my derailleur-equipped bike in its highest gear but I'll slow down considerably going up the same grade. 

If somebody ran behind you pulling at you with five or ten pounds of force you'd feel it. Same if they were pushing you along with the same force as we all know from riding in the wind. 

So if your internally gear hub drops your efficiency by a few percentage points over a derailleur, this is equivalent to another "negligible" force of five pounds or so....which you may not feel on the downhill but definitely can feel going uphill. This is something I learned on the Tour Divide. 

I am not knocking my Rohloff. In fact, I really love it for its other attributes, and, since I am not very fast on any bike, I can live with some inefficiency. The fact that I have something like 2500 miles on my Rohloff with zero maintenance and it's still performing flawlessly cannot be overstated. I've had that thing choked with mud and immersed in creeks. 

But these hubs do have some drag. 

I failed the Tour Divide for other reasons, of course. But the drag and weight from the hub were noticeable on the climbs.


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## fokof (Apr 24, 2006)

Yep , you're right, and I've experienced it too , but I don't make a living winning races , I prefer by a very long shot the advantages over the disadvantages.
Since you raced with it , I can understand your concerns.

If you do your next race with a 1X11 or 1X12 , maybe you'll miss your Rohloff on the first mud puddle 

For me , the added weight was THE major concern for me when I bought my first Rohloff.Now , I don't mind , I would NEVER go back to a derailleur system.
The 2% of lost efficiency over a 3X9 has never bothered me.
http://www.ihpva.org/HParchive/PDF/hp52-2001.pdf
(That was in 2001 compared with 3X9 wich has a lot less chain twist)


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## Ailuropoda (Dec 15, 2010)

fokof said:


> Yep , you're right, and I've experienced it too , but I don't make a living winning races , I prefer by a very long shot the advantages over the disadvantages.
> Since you raced with it , I can understand your concerns.
> 
> If you do your next race with a 1X11 or 1X12 , maybe you'll miss your Rohloff on the first mud puddle
> ...


I will definitely do the TransSouthdakota next summer. I just don't have the fitness or the time or patience for a 2700 mile race (soon to be 3100 I understand) but I know I can tackle an 800 miler. And if I can get my knee back up to speed I may even try the Dirty Kanza. I will ride a 1x11 setup for the Dirty Kanza ( if I do it) because efficiency is everything if you want to cover 200 miles of gravel in 20 hours or less. For the TransSouthDakota I may stick to my Rohloff-equipped El Mariach Ti. It's a wonderful, reliable, extremely rugged bike. Not to mention my load will be a lot lighter as I won't have to prepare for the same extremes of weather you encounter early on inthe Tour Divide.

And towns and services are closer together.


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## Johnny Chicken Bones (Jul 13, 2005)

The Rohloff appeals to me but my eye just can't get used to all that housing hanging off the back. 

One more vanity hurdle I need behind me I suppose.


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## fokof (Apr 24, 2006)

fokof said:


> Wow thanx !
> 
> I would be curious to know the efficiency of a 1X12 drivetrain.
> In fisrt and twelfth , there is a serious chain bent. ( energy loss)


To answer my own question :

https://www.velonews.com/2019/05/bi...ferences-between-1x-and-2x-drivetrains_493185


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## Johnny Chicken Bones (Jul 13, 2005)

There’s plenty to like about a 1x drive train. 
For some bikes, I’m glad to have them. 

But, as you say, there are chain line issues.
I’d say the 1x wave has brought some good things to the bike world but I’d be happy to see it improved on. 
Not sure if they means internal or just a more refined system but am sick of my chain walking off while back pedaling. 
And the increase wear.


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## fokof (Apr 24, 2006)

Interesting video , comparing the Rohloff to Eagle 12 speed.

If you don't speak French ,it says that a Rohloff with a belt has less energy loss than Eagle 12.

I have a little doubt on the scientific process but being a Rohloff fanboy , I'm glad to 
spread the news !


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## Johnny Chicken Bones (Jul 13, 2005)

Interesting. 
Can’t say I learned anything from the video but, since you did-
Was there anything said about how much chain deflection affects the efficiency of Eagle?


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## fokof (Apr 24, 2006)

He measured the energy needed to move forward in each speed on each system.
Everything brand new.
He says he posted his detailed findings but I couldn't find it.


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## fokof (Apr 24, 2006)

Same data but different article









Drivetrain Efficiency: What's The Difference In Speed Between 1X and 2X? - CyclingAbout


Table of Contents The TestThe ResultsWhy Is 1X Less Efficient Than 2X?What Is The Speed Difference Between Drivetrains?How…




www.cyclingabout.com


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## 127.0.0.1 (Nov 19, 2013)

still overall at 'sporty speeds'
2% less efficient than chain and derailleurs unless in the 1x1 gear ratio

"In our article we therefore concluded that hub gears are about 2% less efficient that derailleur transmissions under typical field conditions. We see no reason to change that conclusion."



https://www.hupi.org/HParchive/PDF/hp55/hp55p11-15.pdf



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they have not reinvented physics between that article and today


*A) Power dependent losses.* These are created by friction of parts that are moving under a driving load, i.e. chainlinks, gears, bearings, etc. The quantity of the loss grows proportionally to the transmitted power. 

these losses cannot be demonstrated by hanging weights off a crank on a static system, thing needs to be ridden fairly hard, then these losses escalate
*
B) Power independent losses*. These losses are created by friction of moving parts and are not changed by the driving load, in other words these losses are constant regardless of the load applied, e.g. Gaskets and shims. With lubricants, the quantity of loss depends on speed, temperature, and lubricant viscosity.


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## fokof (Apr 24, 2006)

Well , from the numbers on that article , we talk about 0.5% - 1% difference between a 1 X12 and Rohloff @ 200 watts

"_Note: For the gearbox test, the results showed a marked increase in efficiency as the rate of power increased, so it is likely that if we were to test the gearboxes at 250 watts, they would achieve higher rates of efficiency. I would imagine the Rohloff hub would actually leap-frog the 1X SRAM Force 1 drivetrain in the higher gear ratios! "_

The PDF you link , they probably compared to 3X8 drivetrain back in those days , wich were more efficient ( less chain torsion)


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## Johnny Chicken Bones (Jul 13, 2005)

Pretty sure you can let the drag of internal be a problem. Worry all day and wonder why you’re so slow. 
Or you can let it not be a problem and just wonder about the weather and how the saddle sores are going. 
Or run the internals then don’t wear baggie shorts and figure it’s a wash. 
Plenty of riders try them, and hate them. And plenty have gone around the globe on those ultra long trip riders.


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