Author Topic: The math of a Rohloff oil change  (Read 4251 times)

MacLeod

  • Newbie
  • *
  • Posts: 6
Re: The math of a Rohloff oil change
« Reply #15 on: June 09, 2019, 06:29:04 AM »
Hi Andre, I am for sure not planning to save some money from oil replacement if I buy the 1200 euro gearbox.
I am running steel frame for city commuting. I am planning to upgrade it with rohloff hub, because I like the idea to have straight chainline, sprockets which wear out slowly and immortal hub. I ride around 5000 or 6000 km per year. However my derailleur based 3x9 drivetrain/cassette has not completely gone and I want to ride it until this happens and then upgrade to Rohloff. My question actually is the same as Danneaux mentioned. Does an Rohloff oil wear out from the atmosphere ? If I have open bottle with Rohloff oil, can I use it for example 9 years after it is opened ?
More importantly if I buy the hub now, can I keep it safe in the garage or at home, install it in half or one a year from now, then ride it another year and then change the oil ?

martinf

  • Hero Member
  • *****
  • Posts: 647
Re: The math of a Rohloff oil change
« Reply #16 on: June 09, 2019, 07:47:40 AM »
I use a minimum of 25ml cleaning oil, and a minimum of 15ml all-season oil, the exact quantities depend on how accurate I am with the syringe.  I use one "clean" syringe for injecting new oil, and one "dirty" syringe for removing the cleaning oil/used oil mix.

I reuse the drain plug once or twice, depending on how easy it is to fit, if too easy (Loctite mostly gone) I replace with a new one. Not yet tried sourcing the right kind of Loctite to degrease/treat/reuse the drain plugs indefinitely.

As I have two Rohloff bikes I bought the 1-litre bottles (theoretically more than a 20-year supply for me, but see next sentence) after first using enough kits to get several syringes and tubes and then using up a set of 250 ml bottles (this took several years).

I still have 4 family bikes with old Sturmey-Archer oil lubed hubs with filler caps. I intend trying Rohloff oil in these when I finally use up my stock of genuine Sturmey-Archer oil, which will probably be exhausted this year. These hubs need regular (about monthly) injection of small amounts of oil, I reckon a total of about 100 ml annually.

Rohloff and old Sturmey-Archer hubs are designed to leak oil, the Rohloff very slowly, the Sturmey rather more quickly. For the Sturmey hubs, which have labyrinth seals, this outflow of oil works quite well at preventing the entry of water into the hub, not sure if this applies to the Rohloff with its tighter seals. 

I treat the Shimano Nexus Premium 8-speed hubs differently. I open these periodically (every year for regular use bikes, less for the ones with low mileages), dunk the internals in synthetic gear oil and grease the outer bearings with NLGI 2 marine grease, which I reckon acts as a barrier to water entry.

Andre Jute

  • Hero Member
  • *****
  • Posts: 3343
Re: The math of a Rohloff oil change
« Reply #17 on: June 09, 2019, 10:26:28 AM »
Does an Rohloff oil wear out from the atmosphere ? If I have open bottle with Rohloff oil, can I use it for example 9 years after it is opened ?

I don't know. It is possible; see Dan's logic about the annual oil changes even at 0km. But I'm not fully convinced that hydrophillia, as Dan has it, is the whole answer. The Rohloff gearbox is not sealed against the atmosphere, so water can condense inside it and cause damage quite independently from the oil absorbing water (or not, as the case may be). By itself condensation is already sufficient cause for Rohloff to advise owners to wash out the gearbox with thin oil every year.

Furthermore, I think the fact that Rohloff sells 250ml bottles, nominally a 10-year supply for a private owner, to the retail trade for sale to private owners tells us that Rohloff is not worried about the oil being hygroscopic (attracting water) enough to ruin it. Also, there's the consideration that, if water absorption were a problem, under consumer law, especially strong in Germany, there would be a warning on the canisters to use the oil by either a sell-by date or in a given period after opening it.

There are in fact oils that do not attract water. I believe I have one (another one?) on my bike, in the brake tubes of my Magura Hydraulic Rim Brakes.

Why don't you write to Rohloff, explain your question, and share their answer with us. They're generally quite good with meaningful technical replies.

More importantly if I buy the hub now, can I keep it safe in the garage or at home, install it in half or one a year from now, then ride it another year and then change the oil ?

No, you shouldn't. Your guarantee starts from the date on the sales receipt. So within the first year, even with 0K because the box is sitting on a shelf in your garage, you should change the oil to protect your warranty. And just in case Dan is right.

Explain your plan to Rohloff when you're writing to them, and ask them a) whether they're willing to extend your warranty from when the box is fitted to the bike, b) whether you should change the oil annually while it sits on the shelf, and c) whether it is a good idea to ride a brand-new box for 5-6000km before the first oil change or whether some shorter period in the first year only wouldn't be a good idea to clear out metal particles knocked off the gears of a hand-finished box at the beginning of its service-life.

***

There is no rush to buy the bigger containers of oil. Unless you're going to buy a couple of syringes and screw-in tubes separately, it makes sense to buy a couple of the 25ml full service kits first so that you have the necessary gear (one syringe for clean oil, one for dirty oil) for the service, as Martin has explained.


PH

  • Hero Member
  • *****
  • Posts: 765
Re: The math of a Rohloff oil change
« Reply #18 on: June 09, 2019, 01:56:24 PM »
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.
In the Rohloff Stories book (A bargain from SJS if they still have stock) it has an example of a neglected hub, where the retailer didn't add the initial oil and the consumer didn't do any oil changes for three years.  It says the hub left the factory "With three squirts of oil" (Maybe that's a German technical term!) and the retailer should have added the the oil supplied with it as instructed on the red flyer packaged with it.  However it also says it would have been alright if the owner had followed the manual and done an oil change after a year.
It's all a bit academic and I doubt there's a precise quantity needed, unlike an oil bath where each part needs to dip within a minimum level, the Rohloff oil is intended to coat the components and remain there. On that basis, a bit more than is essential isn't going to do any harm and will find it's way out anyhow. I use 20ml, I also double flush if the first one comes out looking particularly dirty,  probably unnecessary, bur it makes me happy.
As for the question of changing oil after a period of not being used.  That's pretty good practice with anything.  I've had a few motorbikes in my youth and the first thing you'd do if they'd been standing was change the oil.

EDIT - SJS do still have the book 99p! worth adding to your next order if you've any interest in Rohloff
https://www.sjscycles.co.uk/books-publications-dvds/rohloff-stories-book-by-barbara-rohloff/
« Last Edit: June 09, 2019, 03:18:40 PM by PH »

Andre Jute

  • Hero Member
  • *****
  • Posts: 3343
Re: The math of a Rohloff oil change
« Reply #19 on: June 09, 2019, 05:39:13 PM »
I've had a few motorbikes in my youth and the first thing you'd do if they'd been standing was change the oil.

EDIT - SJS do still have the book 99p! worth adding to your next order if you've any interest in Rohloff
https://www.sjscycles.co.uk/books-publications-dvds/rohloff-stories-book-by-barbara-rohloff/

Thanks for the quote from what's surely the authoritative book. Definitely a bargain.

I take the same attitude as you to standing and especially new machinery: Wash the chipped-off bits out!