[Closed] Rohloff drag - some thoughts

Are all the systems same age and got the same amount of oil/lubrication in it? Wondering if it also depends on how fresh everything is and over time it will be more draggy as things wear or get a bit more sluggish...

they get freerer as they bed in which takes 10 000 miles or so.  the one iwas riding today is virtually brand new and I can feel no drag.

7000 miles on mine now since last Jan. no noticeable drag here.
but there must be a bit i suppose.
a bit noisy in 1 to 7 but i dont seem to hear it now.

took me 15 years to decide on a rohloff. i wont change back in a rush. zero maintenance in 14 months.

Rohloffs own figures show very little extra drag

I think that the drag in gear systems are because the teeth slide over each other a bit when they mesh together, and this happens under pressure. In a derailleur setting the rollers mostly only roll when they are not under pressure, I think. Depending on how the forces work as it wraps around a cog.

This guy has done a test.

https://www.cyclingabout.com/speed-difference-testing-gearbox-systems/

The Rohloff comes in low 90s in some gears. I've read plenty of these in the past and the Rohloff usually comes in something like 3-4% under a derailleur as long as the derailleur isn't filthy.

The question is, do you care? Some of us might, and some might not which is absolutely 100% fine with me. But for comparison, my FTP power is circa 300W (actually a little over). Three percent of that is 9W, four is 12W. It takes quite a lot of hard work to put that much power on your FTP. So yeah it's noticeable if you're into performance, but not if you're not.

The main reason I don't have one is the high up-front cost.

the one iwas riding today is virtually brand new and I can feel no drag.

You wouldn't feel it would you? Unless you were doing back-to-back riding on otherwise identical bikes on the same trail in the same conditions.

No I don't care at all looking at this as a lifetime thing.  Was that testing done with a run in rohloff tho?  they get noticeably quieter as they run in so presumably less draggy

The question is why can some folk feel it and others not?  My thesis was its about cadence and torque but thats a bit blown out of the water by ton who IIRC is a low cadence high torque rider.  On the other had he presumably runs it in quicker

dunno really - just pondering

You wouldn’t feel it would you?

Trailrat said he does IIRC hence getting rid of it.  I can feel the drag from more draggy tyres quite easily.  I find that very noticable

Some people are more fussy with bike setup and are more prone to notice subtle things. There's also that you get used to a feeling and no longer notice it. I run an oval chainring on one of my bikes but I can't notice it at all when switching, I used to notice for 5 mins or so of using it.

A standard rear mech has drag but as it's the "normal" setup the average rider wouldn't notice any drag, you only notice a change from the norm.

Looks like pretty good testing and according to that the the rohloff is only 1-2% less efficient than a  derailleur setup that is totally clean and fresh.  Add in a tired / dirty drivetrain and its presumably less.  Its low cadence test tho - my theory is its more efficient at high cadence low torque but I don't really have anything to base that on.  I run a much higher cadence than 60  I bet that difference reduces as the rohloff beds in as well

In the test, a Shimano Ultegra 2X drivetrain achieved an average of 96.2% drivetrain efficiency, while a SRAM Force 1X drivetrain averaged out at 95.1% efficient. This means that a Rohloff hub likely runs 1-2% less efficient, while a Pinion gearbox or Shimano internal gear hub is 5-6% less efficient, on average.

I've put plenty miles onto my Rohloff since 2015. My thoughts -

There is some extra drag in the lower gears, no doubt. However, there's also noise.
My theory is that a fair percentage of the 'drag' is psychosomatic due to the noise.
This is not a double blind peer reviewed study, just my own theory, others will have different experience.
Your theory of more drag at high torque makes sense, it's certainly markedly more noisy compared to spinny pedalling.

What is rarely mentioned is the corresponding lack of drag in the higher gears. 11, the direct one, feels singlespeed smooth to me. the other ones from 12 - 14 are pretty close.
It would be interesting to see the comparitive drag figures for these gears compared to a 12 speed chain turning a teeny 9 or 10 spped cog.
I've geared mine a little low purposefully to tip the balance towards these higher gears.

The hub will only feel better as the miles rack up, this is well documented. There's no guarantee of perfect trouble free riding forever. Mine went back to Germay for new bearings. Done free though.

The lack of maintenance compared to a derailleur setup is ace.

I think that the drag in gear systems are because the teeth slide over each other a bit when they mesh together,

Correctly designed teeth (as presumably Rohloff's are) don't slide - the teeth are shaped to maintain rolling contact with each other. There's bound to be some elastic deformation and rubbing at microscopic scale, of course.

I can't comment too much on the the Rohloff, as I only have one which was bought SH with an unknown amount of running-in already done. My subjective impression was that drag did reduce over a couple of thousand miles, but it's hard to say. Drag was certainly less noticeable than you get with a change of tyres.

I also have a bike with a first-batch Pinion gearbox. That had to go back for warranty work after I'd had it a while, and I suspect that what I got back was a whole new gearbox in the original housing. Drag was noticeably worse when it came back, but this dropped off very quickly (2 or 3 hundred km) until it was silky smooth again.

I’ve geared mine a little low purposefully to tip the balance towards these higher gears.

seems sensible - I gear mine so cruising along on the flat i am in 11 gear as its direct drive (ish)

running 32/16 on a 29er ( which I think is as low as yo are allowed)  i can still spin it to over 30 mph ( downhill)

I really wanted to like my Rohloff but in the end got shot of it due to the drag in the lower gears.
I also lowered the gearing to try and avoid the drag. That just made it more annoying.
People kept telling me it would get better as it wore in. It didn't.
I kept it long enough that it had to go back to Rohloff twice for bearing play then I gave up with it.
I also suffered a lot more rear flats when using the Rohloff than the same bike/rim/tyres with an XT setup.
I'd love nothing more than a gearbox setup what worked and have even though about a Pinion bike but they also seem to suffer from the same kind of drag so haven't gone down that route.

There is some extra drag in the lower gears, no doubt. However, there’s also noise.

No need to reach for psychology. That noise is your pedalling energy being converted in to acoustic energy instead of forward motion.

When I rode TJ's tandem (not a euphemism) I could hear and feel the buzzing in lower gears but that was with two of us putting lots of torque in.

The late simonfbarnes got rid of his due to a combination of drag and unreliability although it's worth noting that he regularly submerged his in river crossings which Rohloff really don't like.

He was totally un-bothered by any bike kit; he was about the least interested in tech or kit of any cyclist I've ever met so he wasn't one to obsess about increments of % of efficiency but even he didn't get on with the drag.

Guessing that they've got better since then and I know that the CyclingAbout guy that @molgrips links to above has done tens of thousands of miles on one with no issues plus various comparison tests.

My mate has an alfine 11 ihg. I use derailleurs.
When we pick the bikes up and spin the rear wheels, it’s definitely noticeable that his slows down more quickly than mine, both have done similar miles, and get similar use (bikepacking)
But there’s no doubt that there’s a difference between them.
However, when actually riding, I doubt this difference amounts to more than a tiny percentage.
He has done the same ‘test’ in his lbs, where the owner actually told him that his particular hub was the most free running of all the ones he’d sold.
I wonder what the results would be in a double blind test, no gear changing, same gear ratio etc, could normal cyclists really tell the difference?

Who said I got rid of mine.

Still have it. Still use it. It's still draggy.

No need to reach for psychology. That noise is your pedalling energy being converted in to acoustic energy instead of forward motion.

The amount of energy needed to make a small amount sounds is very small.

My experience of teaching physics is that people consistently over estimate the amount of energy Wasted as sound

I found this in Wikipedia

https://en.m.wikipedia.org/wiki/Sound_power

Unless I’m reading it wrong a hair drier Is putting out a millionth to of a watt as sound energy. Is a Rholoff louder than a hair drier?

If a Rholoff is inefficient it’s wasting energy as heat.

Guessing that they’ve got better since then

Still exactly the same

sorry trailrat - thought you ditched it

Crazylegs - persumably using a run in one for the testing then?

Unless I’m reading it wrong a hair drier Is putting out a millionth to of a watt as sound energy. Is a Rholoff louder than a hair drier?

I'm not an acoustic engineer but I think you are reading it wrong. It says a 1970s rock concert generates 0.1W of sound power but I'm fairly sure their sound kit would be rated at more than that 🙂

If a Rholoff is inefficient it’s wasting energy as heat.

That too.

The amount of noise a rohloff makes is not 11 w worth or whatever I am certain

Intersting point tho about it being wasted as heat - that should be measurable after a big climb  10 w of heat into a big alloy hub should make a measurable increase in heat over time.

So there we have it.  some users who cannot feel the drag and some who can.  No answers tho as to why.

trailrat - are you a high or low cadence rider?

Not enough heat to melt the snow that was on the surface of mine on Dartmoor after a long climb.

So there we have it.  some users who cannot feel the drag and some who can.  No answers tho as to why.

See also the thread on crank length.

There might be a tiny bit more drag on my pinion gearbox thank on my 12s eagle bike, on a perfectly clean drivetrain, but it's really not an issue especially when the eagle drivetrain gets dirty and starts grinding away.

My gearbox is only about 300km old so it's not really bedded in yet either.

10 w of heat into a big alloy hub should make a measurable increase in heat over time.

It would dissipate fast enough so you wouldn't notice it.

The question is why can some folk feel it and others not?

Nocebo effect.

It would dissipate fast enough so you wouldn’t notice it.

But presumably generated in the cluster and has to dissipate thru the case.   so there should be with say 5 w being generated a measureable increase in heat - I have a sensitive electronic thermometer that can measure 0.1 C.  I might try it one day

I've got an Alfine 8. It seems to get little draggy when slogging away up muddy inclines but I think a large part of this is being able to feel the hub through the pedals.

I serviced it a while back and after way too much internet research, opted for Land Rover ball joint one shot grease. Either I put it back together or the grease isn't great as it's now a little dragging when free wheeling, it would like to drag the pedals round slowly. No change to drag when pedaling though 🙂

I had an alfine 8.  Noticeably cruder than a rohloff.  I lubed mine with ATF and it ran much smoother.  the official shimano refresh is a dunk in oil and the best guess is its ATF

I am between Rohloffs at the moment. I have ridden them for years and thousands of miles but sold my Rohloffed Bike recently because it was a non disk version and the bike was too nice to split. I am debating with myself whether I put one on my ECR. I would do if I wasn’t enjoying to so much with the Eagle set up.

I have swung between thinking they are not draggy at all and then sometimes thinking they are. I am sure that most of that is in my head. As is often said, cycling is a very ‘suggestive’ activity and if I get it in my head that there is something up with a bike then I am usually sure I can feel it… even if really it is just in my head.

The noise/feeling of low gears is a case in point. I tried riding with headphones on to disguise it and it kind of worked. Skinny tyres too… they made my commuting bike feel faster but my journey times hardly changed.

That being said, I don’t use strata or watch speed or times very much so I’m not the most objective in measuring efficiency. I just know when a bike feels right to me.

Have fun with your thermometer, TJ. I rode a Sachs Super Seven up Hautecam on a cold day. It was not cold to the touch compared with any other metal part on the bike. Not warm but not as cold as anything else. I was probably at 230W continuous and suspect the Sachs' efficiency was more Shimano than Rohloff. It did 10s of thousands of Kms with a few drops of oil being added from time to time before the steel frame it was married to broke.

The Sachs had a direct drive middle gear which was obviously as efficient as fixed, that gear was perfect for climbs on club runs. Being dropped by a triathlete pissed the roadies off and being dropped by a triathlete with mudguards and a "putain de boite de cassoulet" took it to the next level.

I might try it one day

Yes definitely, do it in summer on a shady climb.

I've only ridden Shimano IGHs but I'd expect this is about how much you are pushing it - you'll only notice when stomping

“ I’m not an acoustic engineer but I think you are reading it wrong. It says a 1970s rock concert generates 0.1W of sound power but I’m fairly sure their sound kit would be rated at more than that 🙂”

I’m confused by that too. Most sources of sound are bigger sources of heat - big pro sound speakers are only a few percent efficient but with tens of thousands of watt PA systems the acoustic output is likely to be a few hundred watts.

If you can hear your bike making noise you can guarantee it’s making a whole lot more waste heat - but as humans have feeble power output and bikes are big bits of metal surrounded by moving air I can’t imagine you’d notice anything getting warmer from drivetrain losses. Calipers and shock piggybacks certainly do though!

How come you never see a normal bike with a rohloff, they all look like this:

https://www.ebay.co.uk/itm/224862613133?hash=item345adb2e8d:g:V2YAAOSwiS9iCWu5

It was notable in my Alfine 11. The amount of times the wheel would spin for a given pedal input on the Alfine was substantially less than the same bike, with a derailleur/cassette.

Over long rides you could feel the difference in your legs - fatigue kicked in at around 85km on the Alfine, whereas is was ~100 with the derailleur. Part of that would be the weight.

I beg to differ @hexhamstu 🙂

'normal' Rohloff MTB

Whilst all the gearboxers are assembled - anyone got experience of how drag of Kindernay compares to Rohloff / Alfine and how Effigear compares to Pinion? Also what they are like in terms of engagement speed / dead band before pickup?

I'm running a very early model Alfine on my commuter (at least 12 ish years old but constant use and thoroughly ignored for the last 5 years). Did a part strip and ATF lube late last year and it still looks good inside. Bit draggy in some gears and never get away from the spongy sprag clutch feeling. But my current commute is on some filthy riverside bike tracks and I'm very glad not to be running a derailleur, and too many hills to make singlespeed fun. With a heavy steel bike, Alfine, dynohub, mudguards (aero drag) and Marathon Plus tyres, I try not to think about the % of energy being absorbed by the bike.....

It was notable in my Alfine 11

I don't think there's any disagreement that Alfines are draggy. Rohloff are a level above normal hub gears in terms of efficiency and engineering (and physical size!) and this is why they cost 5x as much.

Rohloff are a level above normal hub gears in terms of efficiency and engineering (and physical size!) and this is why they cost 5x as much.

Perceived quality is a real thing

i bought my rohloff after commuting on normal gears for 30 odd years. the last 18 months before retiring were a true PITA regarding keeping the bikes going. bad luck, bad spannering, just bad to the point of nearly jacking the bikes in.
then i retired and bought myself the TI Fargo fitted with a rohloff.
and the last 14 month have been a pure joy bike wise. zero maintenance zero faffing zero cleaning.
well worth the cash in my eyes. long live the rohloff.

Perceived quality is a real thing

You don't think they are better engineered? I was mainly commenting on the efficiency, it seems to do a lot better than Alfine in tests.

Where do you put the putoline on a rorhloff?

I don't really know how a rider would feel drag, or not, in a Rohloff. What sensation do you expect there to be, or not to be? That is the question.

You feel drag in how often you have to pedal to repeatedly overcome it.

Trailrat and I are probably doing what Al says - trying to push on. We raced seriously when we both had Rohloffs and the drag bothered the pair of us. I was a bit of a spinner then. The drag did bother me, and returning to normal gears felt markedly faster. Even today, when I only race ttwo or three times a year, my regular rides without company are almost all done as fast as I can and efficiency is important to me.

I also don't find modern derailleur drivetrains unreliable, and I ride in total filth.

Trailrat and I are probably doing what Al says – trying to push on. We raced seriously when we both had Rohloffs and the drag bothered the pair of us. I was a bit of a spinner then. The drag did bother me, and returning to normal gears felt markedly faster. Even today, when I only race two or three times a year, my regular rides without company are almost all done as fast as I can and efficiency is important to me.

Interesting point. I was struggling to work out whether I experienced drag when I had a Rohloff. It was a different riding experience no doubt - the gripshift and changing gear when stationary being the most obvious mechanical differences, but it also had a different riding feel. I was riding to work in central London during the week, then swapping tyres and riding Swinley etc at weekends. The weight balance felt very different, and the weight being at the back wheel made the bike feel more sluggish in changing direction, shifting the weight of the bike around, or accelerating. And I think it felt like it was perhaps dragging/ less efficient when really standing up and mashing, but I don't know if it actually was draggy.

Excellent piece of engineering overall, and makes even more sense in a time of 1x12 drivetrains than it did when the alternative was 3x9. I never full sorted out the issue of chain tension tbh; that and the weight balance eventually got me to switch back to derailleurs, even though the Rohloff was technically a far better solution

I don’t really know how a rider would feel drag, or not, in a Rohloff. What sensation do you expect there to be, or not to be?

You feel drag when you are pedalling up a hill and think 'flippin eck this is slow I should be going a bit faster than this'. If you only ever ride a Rohloff you won't feel it, no. But if you regularly ride multiple bikes you'll feel it when one is slower than the others.

This is of course due to things like tyres (probably the biggest thing) and also riding position has an effect, but if you have experience with tyres and know what to expect you will notice if something is particularly draggy. It all depends on how sensitive you are to things like this, and how much you care about performance. Again, no right or wrong, and in many ways you are lucky if you don't care because there are of course major advantages to hub gears in the form of maintenance, reliability in mud and so on. Like I say I'd have bought one years ago if it weren't for the cost.

My theory is that a fair percentage of the ‘drag’ is psychosomatic due to the noise.

I rode them for years and have the same suspicion that part of it is the noise and partly the different feel through the pedals. And the weight balance and the friction back-pedalling add to it. I never felt it was an issue, but a conventional bike definitely feels 'livelier'. The Pinion, despite being a heavy bike, didn't feel the same.

bedmaker
...My theory is that a fair percentage of the ‘drag’ is psychosomatic due to the noise....

I think you're right, but it still feels like drag.

Trying hard to love mine. I figure now I'm getting old and frail I might need a few gears, but I think I still prefer my 3 speed Sturmey-Archer. Less gears to confuse me (when I remember to change them). 🙂