Author Topic: Intro, oil leaks, and sprocket chainlines  (Read 13249 times)

TheShipwright

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Intro, oil leaks, and sprocket chainlines
« on: August 25, 2016, 09:59:33 am »
[Admin edit: I have changed the topic header to better track the course of the thread as it evolved from a Rohloff oil leak inquiry to a discussion of threaded vs carrier sprocket chainlines. Because the topics are interwoven, it was not practical to split it as usual. -- Dan]

Hi folks,

I'm new here and thought I'd introduce myself and say hello!

I've lurked on the forum and gleaned quite a bit of info whilst pondering/spec'ing my first Rohloff build.
My build is based around a Singular Gryphon, which for those not familiar with the frame, is a pure 29er frame with an eccentric BB, which I thought would make it ideal for my first foray into the world of Rohloff.   The frame doesn’t have much in the way brazeons, unlike more do-it-all / adventure type frames but that doesn’t concern me as it’s mainly for commuting and the occasional easy off-roading.

I’m a big fan of IGHs having had two Shimano Nexus hubs and an Alfine 8, over the course of last 10 years.

I'm almost there with this build, I just need a few finishing touches, mainly I need to decide on flat or dropped bars (although I've sped this build up to take part in a group ride, hence the flat bars), sort the cables and finally service the Rohloff.

I have a question that maybe people could assist with please.

My question relates to oil leaks.  I’ve noticed a few small oil leaks and I’m not sure if this is normal for these hubs. The other thing to mention is that the hub is second hand/pre owned and I have no idea about the service history.

The first leak, which I’ve only noticed once, is the between the “disc flange” and the hub shell. It was a small amount, maybe a few MLs I guess. It doesn’t seem to have re-occurred.   I’ve also noticed quite a bit of oil when I take the external gear mount/ reaction arm off.  I’m using the Monkey Bone post mount adaptor so had to have this section on and off a few times to get it correctly setup.

I know I can get a gasket for the disc flange/hub shell but should I simply carry out a normal oil service/replacement and monitor it for a while whilst in service OR should I do something before pushing it in service?

I've added some snaps for those who are interested.

Thanks very much.


« Last Edit: September 09, 2016, 06:54:47 am by Danneaux »

Andre Jute

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #1 on: August 25, 2016, 03:48:29 pm »
My question relates to oil leaks.  I’ve noticed a few small oil leaks and I’m not sure if this is normal for these hubs. The other thing to mention is that the hub is second hand/pre owned and I have no idea about the service history.

The first leak, which I’ve only noticed once, is the between the “disc flange” and the hub shell. It was a small amount, maybe a few MLs I guess. It doesn’t seem to have re-occurred.   I’ve also noticed quite a bit of oil when I take the external gear mount/ reaction arm off.  I’m using the Monkey Bone post mount adaptor so had to have this section on and off a few times to get it correctly setup.

I know I can get a gasket for the disc flange/hub shell but should I simply carry out a normal oil service/replacement and monitor it for a while whilst in service OR should I do something before pushing it in service?

I don't know anything about the reaction stay's mounting, but find it odd that it should in any way be connected to the internal lubrication of the Rohloff hub. However, and I give this without looking it up so others can correct me if necessary, Rohloff hubs have a breather hole on the axle, and it is normal for a certain amount of oil to escape via this. An overfilled hub might therefore show oil when you remove a torque stay, depending on where it is fixed to the hub.

On overfilling the hub: you may read on the net, and in Rohloff instructions, that you should fill the hub with 25ml of all-seasons oil. That's a cover-the-manufacturer's-ass instruction. 15ml fills it and the rest will be lost.

Rohloff hubs are not "sealed" in the same way the gearbox on your car is sealed. To save weight, there are, for instance, paper gaskets, and the gearbox "sweats" oil. In the days when I filled my gearbox with 25ml as per the manual, I often had a puddle under the bike, mostly clear because it would happen more often on warm days soon after a service. My wheels get wiped down once or twice a year (I ride on tarmac almost all the time), and the sweat-oil builds up a very thin layer of most clean oil in that time if the hub is filled right, but enough oil to attract dirt if the hub is overfilled.

About the other apparent "leak", I think you need to observe it again and for a good period before you start disassembling anything to replace gaskets. For a start, is any oil coming out around the plug on the feedhole and being flung to the flanges by centrifugal action? That small plug is supposed to be locked with Loctite, which probably also acts as a seal; if you reuse it without cleaning and re-Loctiting it, the seal can be less than perfect. Until I learned about putting in only 15ml of oil, my hub required wiping inside the flanges every once in a while, with no source of the leak obviously visible, and definitely not the seals, which were new, and I always use a new plug with Loctite applied at the factory. Even so, it was by elimination the cause of the overfill leaking.

So I suggest you wait and watch for a bit. Clean the wheel, change the oil in the hub according to the factory manual, which you can download on the net, but put in only 15ml of all-season oil. That ensures that, even if you lose all the liquid oil in the hub (very little actually) through a real leak or by normal sweating, the gears are still properly coated and cannot be damaged by use. Now you can ride and check for the source of the oil. If there is no oil, or only very little from the normal, expected sources, then you're good to go.

I think, considering that the hub is second-hand and you don't know what the previous owner did or did not do, you're right to approach the matter carefully. In general, a Rohloff hub is not as clean as for instance a Shimano HGB (I too have both) and nowhere near as clean as a sealed-for-life hub like the SON hub dynamo that posters here also have. But most would hardly notice, because they clean their bikes more often than I do and because Rohloff oil, especially when most likely to be flung out in larger quantities near a service, is pretty clean stuff, easily mistaken for water.

In general, I take the view that a bit of oil on a Rohloff box does no harm; it may even be the positive sign of a recent service!

Good luck.
« Last Edit: September 09, 2016, 06:48:52 am by Danneaux »

TheShipwright

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #2 on: August 25, 2016, 09:48:46 pm »
Andre,
Thanks for that comprehensive and reassuring reply, I appreciate you taking the time.

Regarding the reaction arm, I proably didn't explain properl, however your explanation has reassured me so I think I'll get on and use it after a service.

Now that I think about the leak that occurred was quite clean and in the back of my mind I think the chap I bought it from said "it's been serviced recently".

Many thanks
Gerry
« Last Edit: September 09, 2016, 06:49:10 am by Danneaux »

mickeg

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #3 on: August 25, 2016, 11:54:07 pm »
Maybe it was the many years that I rode 1960s and 70s Triumph motorcycles that made me immune to oil leakage concerns, but I really don't get bothered by a bit of oil leakage. 

It however makes parts of the hub a dust magnet.

« Last Edit: September 09, 2016, 06:49:19 am by Danneaux »

Danneaux

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #4 on: August 26, 2016, 01:28:40 am »
Goodness!

Not bragging, just observing...

The Rohloff on my Nomad looks pristine, and so did the one on the RavenTour AndyBG so kindly loaned me for my ~9,000km double-crossing tour in 2014. I changed oil on the hub in Germany on the Bulgaria-France leg before the turnaround for France-Black Sea and back into Bulgaria and Romania.

Yes, I wipe mine down on the Nomad and did on the RT, but I'm not even seeing any real sign of misting in-between and dust isn't sticking.

All the best,

Dan.
« Last Edit: September 09, 2016, 06:49:34 am by Danneaux »

mickeg

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #5 on: August 27, 2016, 05:03:11 pm »
Goodness!

Not bragging, just observing...

The Rohloff on my Nomad looks pristine, and so did the one on the RavenTour AndyBG so kindly loaned me for my ~9,000km double-crossing tour in 2014. I changed oil on the hub in Germany on the Bulgaria-France leg before the turnaround for France-Black Sea and back into Bulgaria and Romania.

Yes, I wipe mine down on the Nomad and did on the RT, but I'm not even seeing any real sign of misting in-between and dust isn't sticking.

All the best,

Dan.

So, I take it that the oil coating my EX box and left side dropout is unusual?

Since I do not know anyone else with a Rohloff, I have nothing to compare it to, thus I assume that everything about mine is normal.  The second photo I posted above was in Iceland, I changed the oil a few weeks before that trip and used the ~15ml, not the 25ml theory of volume. 
« Last Edit: September 09, 2016, 06:49:42 am by Danneaux »

Matt2matt2002

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #6 on: August 27, 2016, 05:20:18 pm »
I have flown x2 with my Raven and have noticed oil mist appear on my hub. But since the air pressure on the plane holds is equalized maybe this isn't the cause.

Over filling?

I guess I tend to put a little more oil in than I should - so expect to see some come out.

Hasn't it been said somewhere on this forum that the oil only coats the internal parts. It's not a hub with an oil bath inside.

« Last Edit: September 09, 2016, 06:49:51 am by Danneaux »
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mickeg

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #7 on: August 27, 2016, 05:35:02 pm »
...
Hasn't it been said somewhere on this forum that the oil only coats the internal parts. It's not a hub with an oil bath inside.

Yup.

At home I store the bike vertical when not in use.  But elsewhere, I use the kickstand, so if there was any excess oil inside the hollow axle, it would likely flow out the left side from gravity.  I only lose oil on the left side, not the right (drive side).

Whenever I take the skewer out, it is well coated with oil.  It is my understanding that there is a vent hole inside the hollow axle, thus that would be the expected point of oil loss. 

I am very patient when draining the cleaning oil out of it, I give it a long time to drain so I am sure I left no excess from that.
« Last Edit: September 09, 2016, 06:50:00 am by Danneaux »

Danneaux

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #8 on: August 27, 2016, 06:18:39 pm »
Hi mickeg!

I'm on limited comms at the moment (backcountry with little cell tower coverage) so can't uplod photos at the moment, but will later.

My rear skewer remains *dry*.  :o

Maybe mine is the abnormal one, but it just barely shows any sign of misting to date. Yes, I do wipe it down with the rest of the bike, but it has never come close to expelling fluid. Works really well and quietly. The Rohloff on AndyBG's Raven Tour behaved similarly for me and never even once missed a shift, so 2 for 2 in my experience.

All the best,

Dan.
« Last Edit: September 09, 2016, 06:50:09 am by Danneaux »

Danneaux

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #9 on: August 27, 2016, 07:24:09 pm »
Okay, I have a better connection now. Hopefully these resized photos will show sufficient detail. These were taken after a full day on gravel logging roads *before* wiping down.

To date, this has been typical for me. I use a dust-repelent solution for my wipe-downs, and maybe this helps prevent accumulation.

An aside...a very long front mudflap and Purple Extreme lube go far toward keeping the chain clean.

It is a different story when riding in the fine, sifting talc of Central Oregon, but it settles no worse on my Rohloff than on the rest of the bike.

Best,

Dan.
« Last Edit: September 09, 2016, 06:50:18 am by Danneaux »

mickeg

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #10 on: August 27, 2016, 07:52:24 pm »
I did a google search and found in 2003 on another forum someone said his left side oil leak was solved when he tightened five axle plate screws. 

I bought the hub and set it up for the bike, not SJS.  And I am pretty sure I had four or five screws out back there on the axle plate, so I will tighten them up and see what happens.  But I have over a thousand miles before I am due for another oil change so I probably will not really find out for some time if this (A) fixes the problem or (B) there was no problem in the first place.

Thanks everyone.

ADDENDUM ADDED HOURS LATER.

Those axle plate screws were already tight, but just a tiny bit tighter now.  The hub now was quite clean although I rode it 35 miles on a gravel trail this past Thursday and did not wipe it off after that, so it has been long enough since my last oil change that it no longer is losing any oil.  I am quite sure that the leakage in my other photos was soon after oil changes, I changed it shortly before I went to Iceland this past June. 

The attached photo has a very dark grey area, that is from wiping the oil film off of my skewer today.  An film on my skewer like this is quite normal on my hub.  I am surprised that Dan has no oil film on his skewer, as I assumed an oil film on the skewer is normal.  Somewhere in the Thorn documentation it mentions an air vent in the hollow axle, presumably the oil is leaking from that.

If this is not normal, I wonder why it happens on my hub?  And, what should I do about it?  Or does it not matter?
« Last Edit: September 09, 2016, 06:50:27 am by Danneaux »

Danneaux

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #11 on: August 28, 2016, 02:46:30 am »
I'll check my skewer for you when I get home, mickeg.

All the best,

Dan.
« Last Edit: September 09, 2016, 06:50:36 am by Danneaux »

Pavel

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #12 on: September 01, 2016, 04:36:51 pm »
Oh ... is that stuff called oil?  I thought, that when it was out of a Rohloff, it was "nectar of the gods". Proof of heaven.  :D
« Last Edit: September 09, 2016, 06:50:46 am by Danneaux »

Andre Jute

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #13 on: September 01, 2016, 07:07:07 pm »
Oh ... is that stuff called oil?  I thought, that when it was out of a Rohloff, it was "nectar of the gods". Proof of heaven.  :D

+1. Heh-heh.
« Last Edit: September 09, 2016, 06:50:54 am by Danneaux »

John Saxby

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Re: Intro, oil leaks, and sprocket chainlines
« Reply #14 on: September 01, 2016, 10:59:28 pm »
Quote
Maybe it was the many years that I rode 1960s and 70s Triumph motorcycles that made me immune to oil leakage concerns...

George, they weren't leaking oil, they were just marking their spot :-)
« Last Edit: September 09, 2016, 06:51:05 am by Danneaux »