Author Topic: Pulling down the Rohloff and correct lubrication  (Read 7463 times)

il padrone

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Pulling down the Rohloff and correct lubrication
« on: February 23, 2016, 11:52:36 am »
My son (being the incorrigible engineering geek that he is) chose to pull down his Rohloff for a design principle evaluation - no doubt invalidating the warranty in the process. He has posted a blog article on the task, the reasons for it, and makes a very pertinent technical comment on the reasons to use only the Rohloff hub oil.

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The black part that you see in all of the gear ring disks is not metal; it is either carbon fiber or some other plastic or resin based material. This is partly why you can’t just use any old oil in these hubs, because short chain hydrocarbon molecules can permeate and damage the resin/plastic/carbon fiber parts (maintaining viscosity is the other issue). Ordinary lubricating oil, which is refined from the stuff they get out of the ground, consists of a mixture of different molecule sizes with a spread like a bell curve, ranging from short to long hydrocarbon molecules. Whale oil was one alternative used by early automatic transmissions in cars; it is produced in the whale by a biochemical process that makes lots of the same molecule, so instead of a range of molecule lengths, it is all the same length. This meant that the oil did not change in viscosity either (because there were no small molecules that evaporate easier), which is another factor for the speedhub. Synthetic oil is also all the same molecule, but it is made by an industrial chemical process, and thus no whales are harmed in the manufacture of modern automatic transmission fluid and Rohloff oil. But I digress.
http://matt.signorini.id.au/?p=198

in4

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Re: Pulling down the Rohloff and correct lubrication
« Reply #1 on: February 23, 2016, 01:30:38 pm »
What a fascinating read even if I'll have to do so again before osmosis kicks in. Suffice to say one can further appreciate why the hub costs what it does and why it is regarded so highly..and why its critical to use the correct oil.
Thanks for sharing.

mickeg

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Re: Pulling down the Rohloff and correct lubrication
« Reply #2 on: February 23, 2016, 03:45:10 pm »
Last time I bought Rohloff oil, I decided to splurge and buy the 250 ml containers instead of the little single use ones.  I added it to my order when I bought my headlight from Germany (for shipment to USA) last year, adding it to my order did not add any shipping cost.  Each oil change I do for the next several years will cost less than $4 USD.

I replaced an O ring on a camping stove pump with one rated for exposure to petroleum compounds.  Although it should not have had any problem with exposure to camp fuel, it swelled a little and that makes it very hard to operate the pump on that stove.  Compatibility of all parts with the chemicals they are exposed to is pretty important. 

energyman

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Re: Pulling down the Rohloff and correct lubrication
« Reply #3 on: February 23, 2016, 03:59:44 pm »
I did an oil change on two Rohloffs this afternoon.  I poured the waste oil over a magnet and from the amount of metal particles in the oil I just hope that there is something left in the gearbox  :D  !!!!!

One thing I can't understand is why the waste oil is aways so black.  Car engines etc I can understand but there are (hopefully) no products of combustion in my bike hubs.
Anyone any ideas please ?
« Last Edit: February 23, 2016, 04:02:54 pm by energyman »

geocycle

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Re: Pulling down the Rohloff and correct lubrication
« Reply #4 on: February 23, 2016, 05:24:28 pm »
Thanks for sharing il Padrone, there is some very clever engineering in the box and it takes a very clever engineer to explain it.  I'm in awe of anyone who could take one apart, put it back together and find that it works!
 

Danneaux

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Re: Pulling down the Rohloff and correct lubrication
« Reply #5 on: February 23, 2016, 05:38:02 pm »
I liked this part best...
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Dad’s expression of horror was quite entertaining.
  :D

Well done, Son Matt. Well done, Dad Pete.

All the best,

Dan.

Andre Jute

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Re: Pulling down the Rohloff and correct lubrication
« Reply #6 on: February 23, 2016, 06:46:46 pm »
Well done, Matt! Bonus points for getting it together again.

mickeg

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Re: Pulling down the Rohloff and correct lubrication
« Reply #7 on: February 23, 2016, 06:55:41 pm »

Matt2matt2002

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Re: Pulling down the Rohloff and correct lubrication
« Reply #8 on: February 23, 2016, 08:43:58 pm »
So....
If I'm on tour in a remote area and need an oil change, I look for the nearest whale?
Never drink and drive. You may hit a bump  and spill your drink

Danneaux

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Re: Pulling down the Rohloff and correct lubrication
« Reply #9 on: February 23, 2016, 08:49:34 pm »
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So....
If I'm on tour in a remote area and need an oil change, I look for the nearest whale?
Nooo...look for the Other Matt (Pete's son)!  ;) :D

All the best,

Dan.

Andre Jute

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Re: Pulling down the Rohloff and correct lubrication
« Reply #10 on: February 23, 2016, 09:48:24 pm »
Quote
So....
If I'm on tour in a remote area and need an oil change, I look for the nearest whale?
Nooo...look for the Other Matt (Pete's son)!  ;) :D

Matt2Matt2Matt?

David Simpson

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Re: Pulling down the Rohloff and correct lubrication
« Reply #11 on: February 23, 2016, 09:59:57 pm »
So....
If I'm on tour in a remote area and need an oil change, I look for the nearest whale?

Realistically, you probably won't find a suitable whale nearby. I recommend packing your own whale, as part of your maintenance kit. As an added bonus, a whale is much cheaper than Rohloff oil, if you consider how many oil changes you can get out of a standard-sized whale.

- DaveS

mickeg

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Re: Pulling down the Rohloff and correct lubrication
« Reply #12 on: February 23, 2016, 10:35:41 pm »
Which species of whale do you use for cleaning oil and which for lube oil?

David Simpson

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Re: Pulling down the Rohloff and correct lubrication
« Reply #13 on: February 23, 2016, 11:32:52 pm »
Which species of whale do you use for cleaning oil and which for lube oil?

That's my secret. But let me say that I'm really glad I bought a Nomad. ;)

More seriously... Pete, pass on my congratulations to your son for not only managing to disassemble a Rohloff hub and a dynohub (and putting them back together again!), but also for being able to write about it so well. It is a valuable combination to be able to excel in the technical aspects and to communicate so well. I'm looking forward to more of his postings, both about bikes and also about computers (my two favourite topics).

[Edit: And congratulations to you Pete, for raising such a son.]

- DaveS
« Last Edit: February 23, 2016, 11:40:31 pm by davidjsimpson »

onmybike

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Re: Pulling down the Rohloff and correct lubrication
« Reply #14 on: February 24, 2016, 10:40:00 pm »
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Which species of whale do you use for cleaning oil and which for lube oil?

I'd keep it simple and just use a multi-porpoise oil for both.