Author Topic: The math of a Rohloff oil change  (Read 4258 times)

Andre Jute

  • Hero Member
  • *****
  • Posts: 3343
The math of a Rohloff oil change
« on: April 16, 2016, 07:52:52 PM »
I've just used the last of set of Rohloff oil change kits I bought with the bike nearly nine years ago. Over time a little of the oil evaporates or leaks out, so this time I put in 22ml of cleaning oil. I ran the motor to turn the rear wheel while changing between gears 3 and 5, which between them engage all the epicyclics, so spreading the oil on all surfaces, then let the box stand for an hour with the drainage plug downwards. I turned the hub briefly through forty-five degrees to insert the tube again without making a mess, then with the plug pointing downwards left the syringe attached for a couple of hours. 22ml of slightly soiled oil came out.


That leaves 14ml of thin winter/cleaning oil attached to the gears, right?

Next I added what was left in the bottle of all-seasons running oil, which was about 22ml. None of this was spilled. I put the new plug in, gave the wheel a good spin, and took a 15km ride, noting that the box ran a small bit more silently. The box has 8600km/a bit over 5000m on the clock, so I expect it is about as quiet as it will ever be; thus the small bit of silencing an oil-chance seems to make could easily be a psychosomatic artifact, something you hear because you really want to hear something for your effort. (Riding on smooth tarmac on the painted line, the whoosh of the tyres should totally drown out any noise a sound Rohloff gearbox makes. If your bike has more than 2000 miles on the box and it is still noisier than that, consult the seller.)

But this math is cockeyed. We have been told, repeatedly, that a Rohloff gearbox is fully serviced by the 14ml of oil that sticks to the gears. But in my box every time I service it, there is 14ml of slightly dirty (because mine is a low-annual mileage by the standards of some of the tourers here) mixed new winter/cleaning and oil all-seasons oil sticking to the gears, which you cannot and shouldn't remove, further mixed with 20-25ml of brand-new all-seasons oil. I make that something around 34-39ml of oil. Even if you put in only a carefully measured 14ml of all-seasons oil, that's a minimum of 28ml in the box.

Since my box doesn't leak oil, I conclude that's a proper amount of oil in the box.

Thoughts?

***

In the Middle Ages, the committed would torture themselves to madness with this sort of metaphysical question, often in the form of, "How many angels can dance on the head of a pin? And, when you solve that one, how many angels can dance on the point of pin?"
« Last Edit: April 16, 2016, 07:55:10 PM by Andre Jute »

John Saxby

  • Hero Member
  • *****
  • Posts: 1610
Re: The math of a Rohloff oil change
« Reply #1 on: April 16, 2016, 10:55:08 PM »
Enough to make my head spin, Andre, and I don't (think I) have any epicyclic gears inside my noggin.

I've forgotten the slippery arithmetic from my Nov/2015 oil change, but on my two brief rides last week, I was chuffed to hear how quiet was the Rohloff--or better, not to hear how quiet it has become.  I have about 5500 kms on the clock now, and with the reduction offered by the 36 x 17 ring/sprocket ratio, I spend a lot of time in the upper, quieter register.

The temp will be up around 17 tomorrow, with a sunny day forecast, so I'll take my first long-ish ride, a there-and-back of about 100 kms south of the city along the Rideau River & canal. I expect to hear not much at all from the back wheel, what with the hum of the tires and the boidsong all about  :-)

Mike Ayling

  • Full Member
  • ***
  • Posts: 176
Re: The math of a Rohloff oil change
« Reply #2 on: April 17, 2016, 08:49:37 AM »
I ran the motor to turn the rear wheel while changing between gears 3 and 5, which between them engage all the epicyclics, so spreading the oil on all surfaces,


Don't understand the motor bit
is it electric?
If it is in the bottom bracket how can you run it?

Mike

mickeg

  • Hero Member
  • *****
  • Posts: 1772
Re: The math of a Rohloff oil change
« Reply #3 on: April 17, 2016, 03:41:10 PM »
I do not worry about the math.  I did an oil change yesterday, I did not even look at how much cleaning oil came out.  I put in 16 ml of new oil.

I think the first oil change accomplishes the most silencing. 

About a year ago I got the 250ml bottles of oil from Bike24, they had a pretty good price.  For me this is probably a lifetime supply.  Since I was already getting stuff from them (my AXA Luxx 70 Plus headlamp), adding the oil to the shipment did not increase my shipping cost any so it was a real bargain.  I am in USA and anything that has the word Rohloff on it costs a fortune here as there appears to be one distributor that enjoys a monopoly.

I have never had a drop of oil leak out and drip on the floor, but when I take the skewer out I can see that oil is clearly coming out.  And my dropouts and everything else nearby gets a nice coating of oil on it.  So, I know that over time a lot of oil is slowly coming out and coating everything.  The photos shows how the oil coating everything is a pretty good dust magnet.

Andre Jute

  • Hero Member
  • *****
  • Posts: 3343
Re: The math of a Rohloff oil change
« Reply #4 on: April 17, 2016, 04:40:15 PM »
Mike: The bike I did the Rohloff oil change on is a Utopia Kranich; it has slider dropouts fo chain tensioning rather than an eccentric bottom bracket. The motor is a Bafang central type fitted to the bottom bracket. To spin the rear wheel, I put the stand, attached to the reinforced frame end, down, tilt the bike on it just enough to clear the rear tire, and run the motor. On the eighth page here you can see the multiple tubes and strap bracing that side of the frame end, in case you wonder whether I'm not wrecking my frame; my frame is stiffer than Dr Fiedler's big Rolls-Royce monocoque, an exemplary design. That allows me to do the entire gearchange inside even when it is freezing out; inside you have the advantage that the heating keeps the oil pretty fluid, so you can count on getting the box really clean and all the dirty oil out.

I agree with you, George: "I think the first oil change accomplishes the most silencing." I'm about to buy a pair of 250ml containers of oil from Bikecomponents.de, my preferred pusher, because I have to replace my spare tyres and tubes anyway and may as well pad the order and share the postage, same as you did. I have plenty of syringes and tubes and spare Locktited plug-bolts (which are anyway not a problem to reuse).

Mike Ayling

  • Full Member
  • ***
  • Posts: 176
Re: The math of a Rohloff oil change
« Reply #5 on: April 21, 2016, 10:11:34 AM »
Nice bike Andre, like the gold pin striping on the green!

Mike

Tiberius

  • Jr. Member
  • **
  • Posts: 99
Re: The math of a Rohloff oil change
« Reply #6 on: April 21, 2016, 12:32:18 PM »
Not sure about the maths but curious as to the amounts of fresh oil you guys put into the hub at oil change time....

Rohloff say 25ml....SJS video says 15ml.....You guys various ml.....?????....... ???

mickeg

  • Hero Member
  • *****
  • Posts: 1772
Re: The math of a Rohloff oil change
« Reply #7 on: April 21, 2016, 03:37:48 PM »
Not sure about the maths but curious as to the amounts of fresh oil you guys put into the hub at oil change time....

Rohloff say 25ml....SJS video says 15ml.....You guys various ml.....?????....... ???

My target was 15ml, but the syringe moves rather jerky when you push it and I got 16ml in it.  I did not want to try to push the 1ml back into the bottle.  Perhaps it is the engineer training in me that caused me to be that precise in my posting here. 

I have also seen 8ml, but my hub costs too much money for me to skrimp that much.  Thus, I aim for the 15ml number.  At these links do a word search to find the reference to 8ml.
http://www.sjscycles.com/thornpdf/ThornBikeOwnerManual2Web.pdf
http://www.sjscycles.com/thornpdf/thornlivingwitharohloff_lores.pdf

As I noted above, I bought the 250ml bottles a year ago, thus I have a big supply of oil and have no reason to scrimp.  Plus, there is no downside to use 15ml if only 8ml is necessary.  Thus, I plan to continue using 15ml.

I am not sure if I should start to try to only use 15ml of cleaning oil or if I should continue to use 25ml, but it will be a year before my next oil change so I have some time to think about it.

And, yes I did put new blue Loctite on my drain screw.
« Last Edit: April 21, 2016, 03:40:16 PM by mickeg »

Tiberius

  • Jr. Member
  • **
  • Posts: 99
Re: The math of a Rohloff oil change
« Reply #8 on: April 23, 2016, 08:57:34 AM »
Not sure about the maths but curious as to the amounts of fresh oil you guys put into the hub at oil change time....

Rohloff say 25ml....SJS video says 15ml.....You guys various ml.....?????....... ???

My target was 15ml, but the syringe moves rather jerky when you push it and I got 16ml in it.  I did not want to try to push the 1ml back into the bottle.  Perhaps it is the engineer training in me that caused me to be that precise in my posting here. 

I have also seen 8ml, but my hub costs too much money for me to skrimp that much.  Thus, I aim for the 15ml number.  At these links do a word search to find the reference to 8ml.
http://www.sjscycles.com/thornpdf/ThornBikeOwnerManual2Web.pdf
http://www.sjscycles.com/thornpdf/thornlivingwitharohloff_lores.pdf

As I noted above, I bought the 250ml bottles a year ago, thus I have a big supply of oil and have no reason to scrimp.  Plus, there is no downside to use 15ml if only 8ml is necessary.  Thus, I plan to continue using 15ml.

I am not sure if I should start to try to only use 15ml of cleaning oil or if I should continue to use 25ml, but it will be a year before my next oil change so I have some time to think about it.

And, yes I did put new blue Loctite on my drain screw.


Many thanks for the info'

I'm just about to do my hub's first oil change.....15ml it is..... ;)

MacLeod

  • Newbie
  • *
  • Posts: 6
Re: The math of a Rohloff oil change
« Reply #9 on: June 08, 2019, 09:41:35 PM »
The creator of this topic puts in his hub a 9 years old oil ?!?
So why Rolhoff recommends to change oil on 5000 kms or on every year even with 0 kilometers ?
How it is fine to put 9 years old oil then (on 0 kilometers) ?
Either this is not good practice, or Rohloff are too conservative in their oil change recommendations. Which of both it is ?

PH

  • Hero Member
  • *****
  • Posts: 765
Re: The math of a Rohloff oil change
« Reply #10 on: June 08, 2019, 10:39:29 PM »
Either this is not good practice, or Rohloff are too conservative in their oil change recommendations. Which of both it is ?
There's nothing to say that the oil in the bottle deteriorates with age, Id expect there to be a clear use by date if there was.
There's several reasons you'd still change the oil in the hub even if you'd not used it, settlement, separation (You should shake the oil in the bottle before use)  evaporation, leakage, or simple the flush to keep everything coated and clean.
I don't think there is any contradiction, I'm sure Rohloff are conservative in their recommendations, it'd be a bit convenient if the exact timescale required was precisely one year, but it's easy to remember and I'd rather be doing it a little too often than not enough.
« Last Edit: June 08, 2019, 10:41:44 PM by PH »

MacLeod

  • Newbie
  • *
  • Posts: 6
Re: The math of a Rohloff oil change
« Reply #11 on: June 08, 2019, 10:53:33 PM »
Ok,
so it is logical the next question:
When you buy a new hub, you do not know if it has stayed in storage for a year or more. Does it mean that you should always change the oil of the new hub before riding it ?

PH

  • Hero Member
  • *****
  • Posts: 765
Re: The math of a Rohloff oil change
« Reply #12 on: June 08, 2019, 11:37:27 PM »
I'm pretty sure they're supplied to the retailer dry and the oil is added by them.
But yes, it's good advice to do the first oil change early.

Andre Jute

  • Hero Member
  • *****
  • Posts: 3343
Re: The math of a Rohloff oil change
« Reply #13 on: June 08, 2019, 11:59:19 PM »
The creator of this topic puts in his hub a 9 years old oil ?!?
So why Rolhoff recommends to change oil on 5000 kms or on every year even with 0 kilometers ?
How it is fine to put 9 years old oil then (on 0 kilometers) ?
Either this is not good practice, or Rohloff are too conservative in their oil change recommendations. Which of both it is ?

Hi, McLeod. I'm Andre Jute, the creator of this thread. I'm sorry we're having this misunderstanding. I'm a novelist, so I don't try for the brutal clarity of the engineers, like George (mickeg). But I think we can enlighten your confusion with a few facts that are all beyond dispute by experienced Rohloff owners and riders and mechanics.

1. Rohloff tells you plainly in the manual and on their site that you must change the oil in your Rohloff gearbox every 5000km/3000m or every year, whichever comes first. If you're on tour, they will be understanding of a limited overrun. However, Rohloff is so serious about the oil changes, even in a year in which the box covered, as you say, 0km, that they will take away your very valuable warranty if you do not perform these routine services. That's not all. Rohloff is famous for not charging customers even beyond the guarantee period as long as they have not abused the gearbox by, among other possible abuses, failing to change the oil.

2. The Rohloff manual states that the box holds 25ml of oil, and this is the amount of all seasons oil that beginners should insert after the cleaning oil is drained. However, OEMs (bicycle manufacturers who fit Rohloff as original equipment, such as Thorn) are well aware of three other facts:

2.1 Your Rohloff, everyone's Rohloff, left the factory with 12ml of oil clinging to the gears, and can safely be run on this amount for the first year. So, so some people conclude that 12ml is a safe minimum to aim for.

2.2 But the question is, how will you measure exactly 12ml, absolutely no less. Most of us, and certainly not the people who sell bikes and will have to replace a very expensive gearbox if they screw it up by being cheap about a couple of millilitres of oil, just aren't going to take the chance. So 14ml just grew to be accepted by most people as a safe amount of new oil to put in every year or 3000m/5000km, whichever comes first.

2.3 Rohloff will not penalise you under -- again -- the very valuable if unspoken extended warranty that in practice they give you if you regularly put in 14ml rather than 25ml.

3. Rohloff continuously develops the two oils, the cleaning oil (which is also the ultra-cold winter oil) and the all seasons oil (which is the one most of us would normally use). But the fact that they sell these oils in volumes up to one litre (which is 40 services!) to the retail trade for selling on to individual customers, rather than supplying these large cans of oil exclusively to the Rohloff service trade, tells you Rohloff isn't worried that the oil will somehow over time lose its potency even over a period measured in decades. So it doesn't matter that I'm using an oil kit that I bought in bulk nine years ago. The important information is that the Rohloff was regularly serviced once a year (I never rode it more than 5000km in any year). Actually I bought ten kits, and serviced the box twice in the first year, once after a few hundred kilometres to get the bits of metal knocked off the teeth out, plus another time to re-establish the regular routine of servicing the bike in January, an easy date to remember.

***
I have no idea where the 8ml amount mentioned above came from, nor any interest in finding out whether it is a realistic service amount. It's enough for me that 14ml, easy to measure, is adequately more than the 12ml factory minimum to give me a margin of safety. It's not that I can't afford another Rohloff box, though it is an expensive item, it is that my Rohloff is just nicely run-in to where it changes almost as smoothly as Shimano's Nexus Premium (a landmark for me), and the Rohloff's noise floor, always very low, has dropped permanently below ambient noise on the quiet country lanes where I ride, so this particular Rohloff box is precious to me. (If you think that's being over-finicky, read on this forum Danneaux the Moderator's persistent questioning on the subject of noise before he bought a Rohloff. Those are all questions I would have asked before I bought a Rohloff, if only I knew who to ask...)

You're right. Rohloff is over-conservative in their servicing demands, but with a box so expensive do you really want to save a few pennies every year on oil? The actual reason for private owners, as distinct from bicycle workshops like Dave's at Thorn, to put in 14ml or some near-volume like 15 or 16ml, is to prevent misting-out of oil, and oil drips via the breather hole, and thus to save on cleaning-up. If you have the EXT klickbox, Rohloff is wildly over-conservative in demanding that it be serviced every 500km -- that's right, 500, not 5000. I ran an experiment in which I determined that, if you fill the EXT klickbox to the brim with a superior quality of grease, for a low-miles rider like me, servicing it at the time of the oil change is more than adequate. I went up to 2500km between services of the EXT klickbox and the grease wasn't even discoloured, never mind dirty or thin. German cover-your-assery is a wondrous, maybe even unique example of cost-accounting creating unnecessary expense.

***
Don't hesitate to ask for clarification of anything you don't understand, or any further questions. If I do not know the answer, someone else will.

Danneaux

  • Administrator
  • Hero Member
  • *****
  • Posts: 7676
  • reisen statt rasen
Re: The math of a Rohloff oil change
« Reply #14 on: June 09, 2019, 02:19:04 AM »
MacLeod's questions tangentially raise an interesting point I have not seen answered: Is Rohloff's oil hydrophilic?

Ages ago in another life, I owned an auto repair shop and from that experience, know brake fluid definitely has a shelf life -- typically 12 months or so - after it has been opened. Even capped, foil-sealed bottles are only good for about 2 years after time of bottling. Using it beyond that point risks moisture absorption which in turn lowers the boiling point of the fluid and can cause internal corrosion of the pistons and lines and causes seals to deteriorate.

Looked at from this perspective -- if Rohloff oil is similarly hydrophilic (atmospherically moisture absorptive) -- then the company's recommendation for a time-based (i.e. annual) oil change makes sense (the mileage component is obvious, based on actual wear). If the oil in a hub could absorb water from the atmosphere, then the oil in a previously opened bottle could also. Also, if one does buy bulk quantities, then you miss out on the periodic refinements Rohloff makes to its oil formulations.
-----
Quote
If you think that's being over-finicky, read on this forum Danneaux the Moderator's persistent questioning on the subject of noise before he bought a Rohloff.
<nods> Yes, still important to me as I value a quiet bike and it is also helpful for riding in areas where there is wildlife that can be spooked by the "bright" noises of a freewheel. Using a special grease injector, I pump Phil Wood grease into the freewheels of my derailleur bikes annually and so coast silently. My Rohloff has worn in to the point where it is largely silent under drive except for a gentle whir in Gear 7, but the freewheels remain loud in half the gear range so I use care to still turn the pedals when I am near wildlife I want to see. On a recent ride, I passed within 6m of a mother black bear and her cub as I rounded a corner. I'm not sure that could have happened if I had been riding a noisy bicycle.

Best,

Dan.