Author Topic: Rohloff oil colour  (Read 3174 times)

Andre Jute

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Rohloff oil colour
« on: April 18, 2010, 06:34:55 PM »
In January I changed the oil in my Rohloff hub for the first time at about 2200km and 12 months. I was a bit surprised after an hour to withdraw much less than predicted by the manual of the cleaning oil plus the old oil presumed to be in the hub. Reference to this board reassured me that is normal for first oil changes (only on the first change, right?) and I decided to let it ride. The refill set I received had leaked a bit during carriage, so I put in about 20ml of fresh oil, max. I would say that I may not have drained the cleaning oil out properly but I certainly didn't overfill it with fresh all-seasons oil.

However, there was a drip over quite some period. Truth is, I don't know how long or how much as the bike was not used all that often because of the weather. My wife noticed the tiny puddle on the tiles and put down a piece of paper towel over it. Perhaps a square inch, certainly not as much a two square inches, of paper towel was stained. I rode the bike a bit and a couple of weeks later noticed another discharge on the tiles, a few millilitres, not as much as the first time round. The leak has long since stopped.

When it was first noticed, I inspected the gearbox and environs but found no obvious source for the leak. Now I see this in another thread -- 
The hub is 'meant' to breath[e] into the middle of the axle on the CC version (quick release) or into the right hand stud on the TS version (nutted).  So I presume in your case the hole has / had become blocked and this condition resulted.

stutho

-- so, since I have quick release hub (with a nut on the quick release axle replacing the quick release lever for a little added security), I assume the oil escaped along the axle axis and dripped clear onto the floor because the bike was parked at an angle on the stand on the left, non-drive side. That would account for me not finding the source of a leak of transparent oil.

What concerned me more than not finding the source was the *colour* of the oil that dripped out. It was almost clear. In fact, it was only when it lightly stained kitchen tissue when dry again that I was certain it wasn't water condensing on the metal parts... I concluded, as I said above, that I had left some cleaning oil in the gearbox and now it was coming out again because, together with the normal oil, the box was overfilled.

Once more I wasn't worried. The gearbox seemed to operate well in the cold weather and even on a fast ride of 17km, perhaps long enough to get the gearbox warm, on the only warm day (14 deg C) we had this year. The cleaning oil is, after all, also oil, and recommended by Rohloff for extreme cold conditions. Temperatures in Ireland rarely reach even 20 degrees and my longest ride is 22km with a long break in the middle, so the box probably never gets up to the kind of temperature it was very likely designed for (it's an offroad competitions box, in the first instance) and for which the all-seasons oil is specified.

No further leaks since then.

However, now that we hope the summer may yet be warmer (today I put the central heating back on!), a few questions arise:

1. Should the all-seasons oil be shaken?

2. Why would only clear cleaning oil drip out of an overfilled gearbox?

3. Am I in danger of damaging the gearbox?

4. Even if not, should I repeat the oil change as a precautionary measure?

Andre Jute

julk

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Re: Rohloff oil colour
« Reply #1 on: April 18, 2010, 11:26:44 PM »
Andre,
1. I shake my refill oil before decanting the fill amount from a larger bottle, but only because there could be some settlement in the larger bottle. I dont shake my flushing oil, maybe I should...
2. The only cause I can think of is incomplete mixing of the oils in the hub during the oil change. I would not be worried by this - as you say the flushing oil is recommended as refill oil for colder temperatures and we have had some of those.
3. I doubt it as long as you have some oil in and change it annually to get any water ingress out.
4. I did a double oil change early in my hub life but only because I was getting a bit of gear slippage and notchy changes and the double oil change was recommended by SJS to give the hub an extra flush for particles resulting from the running in.
Julian.

pdamm

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Re: Rohloff oil colour
« Reply #2 on: April 19, 2010, 11:47:46 PM »
Andre

1.    Yes you should shake the oil before using it Ė although I didnít read that part on the oil can label for the first few oil changes.

2.   During your oil change and after you put the flushing oil in did you run the hub for a while?  Then manual says to ride for a km or so, or spin the wheel with the pedals while changing through all the gears.  It could also be that the oil separated out while the bike was not being used.  I have had a few oil leaks but not very often.  They have always been black but then I ride my bike almost every day.

3.   I doubt it and agree with Julian.

4.   If never hurts to do another oil change.  But I suspect there is no need.  You could e-mail Rohloff and ask them.  If the oil has separated out while the bike is stationary and some of the clear component has leaked out then the overall makeup of the oil has changed a bit.  But since you still have oil in the hub I doubt it will be doing any damage.  If the ratio of the different components of the oil was critical then I would expect warnings in the manual about the sort of thing you have experienced.

Peter
 

stutho

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Re: Rohloff oil colour
« Reply #3 on: April 20, 2010, 01:05:52 AM »
Andre,

On the first oil change you always get less back  - as some oil is left sticking to the gears inside the hub


>1. Should the all-seasons oil be shaken?
I have NOT seen it separate and I have had a larger bottle in the garage for a couple of years! But yes I would probably shake it up (by reflex as I pick it from the shelf)  - it can never hurt!


>2. Why would only clear cleaning oil drip out of an overfilled gearbox?

When you added the new multi season  oil did you use the filling tube and a syringe?  If you DID then what may of happens is that the positive pressure from the syringe may pushed some of the cleaning oil into the breather tube / axle space.  (This is conjecture on my part). which has subsequently found it way onto your floor.

>3. Am I in danger of damaging the gearbox?
I don't believe so

>4. Even if not, should I repeat the oil change as a precautionary measure?
Personally I wouldn't - but a oil change is always a good think to do (except on you wallet)



    
« Last Edit: April 20, 2010, 01:13:18 AM by stutho »

Andre Jute

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Re: Rohloff oil colour
« Reply #4 on: April 20, 2010, 02:10:17 AM »
Gentlemen

Thanks for your replies. In reply to your questions, plus a little additional information:

I followed the instructions for changing the oil; I found the most easily followed instructions were those by Andy Blance on the Thorn netsite. I used the standard syringe supplied with the refill set. I took a 3km ride to mix the cleaning and other oil inside the hub. The mix withdrawn was black, leading me to believe that the old oil and cleaning oil mixed well enough inside and that the withdrawal, even if the amount was not huge after an hour with the syringe hanging under the hub, was done properly. I also withdrew the 20ml of air in the instructions, which should have released any "air lock" effect. The service was done in a centrally heated space so the oil wasn't cold. The old, discarded oil didn't feel gritty at all, but then why should it after only 2227km of very light use for such a sturdy hub? The clear oil that leaked out after the oil change left just the slightest few pinheads of greyish discolouration on the paper.

In the light of what you say, I think that what I'll do once I have a refill kit, already ordered, to hand is to withdraw everything that wants to come out of the box. If it is mainly clear cleaning oil, something went wrong with my oil change, and I'll just do a complete oil change with a new kit. If what comes out is mainly standard all-season oil and it looks new and uncontaminated, then the surplus cleaning oil has already dripped out and I'll just put the clean all-season oil back in. That way I don't willy-nilly waste a refill kit, but I still reassure myself that I'm not wrecking an expensive hub gearbox either, and if an error was made I will discover and correct it. I don't see any reason not to use the bike until then; after all, there is so much oil of one kind and another in there that part of it found a way out!

Thanks again.

Andre Jute

expr

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Re: Rohloff oil colour
« Reply #5 on: April 20, 2010, 10:09:32 PM »
Hi Andre,

I would be tempted to do the same test myself. The only way in which clear oil can escape in concentrated amounts without black discolouration has to come from the way in which you filled it with the cleaning oil and the angle of the hub, and the inherrant pressure that was induced into the hub on filling. It would be quite a slim chance of creating the same situation again anytime soon. The breather inside the hub on the qr models link to pic here ,


http://i705.photobucket.com/albums/ww53/daveshell/bike/IMG_2197.jpg


is in the middle of the hub so the fresh cleaner oil must have dribbled over the axle and then have become forced out through the breather/ shaft seal.

What I tend to do now is drain and refill through the hub bearing after taking off the rear sprocket which makes the whole operation quicker and easier without fear of forcing the oil in.

You can run your bike on 100% cleaner oil if you wish, but this is advised for very cold climates.

Dave.

sbseven

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Re: Rohloff oil colour
« Reply #6 on: April 20, 2010, 10:46:19 PM »
What I tend to do now is drain and refill through the hub bearing after taking off the rear sprocket which makes the whole operation quicker and easier without fear of forcing the oil in.

Interesting. Do you use the Cleaner Oil at all during this process?

stutho

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Re: Rohloff oil colour
« Reply #7 on: April 21, 2010, 12:07:03 AM »
Quote
What I tend to do now is drain and refill through the hub bearing after taking off the rear sprocket which makes the whole operation quicker and easier without fear of forcing the oil in.

Wow! I wish I had thought of this! Excellent! I am going to try that method next time I do a change!

Andre Jute

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Re: Rohloff oil colour
« Reply #8 on: April 21, 2010, 06:58:09 PM »
Thanks for the advice, Dave, and taking the trouble to provide a photo.

At the time I wondered about the airtight way the syringe pipe screws into the hub, and where the air would go when you start pushing in cleaning oil. Presumably the instruction to withdraw 20ml of air as the last action before putting the closing screw back in is intended to the equalize pressure inside the hub. Pressure must be, as you say, the key to what happened here -- out of the hot air of a centrally heated house into air outside cold enough, my family now reminds me, to have a worn a padded leather jacket for the short ride, and to have attracted remarks about being crazy to go out. As you say, not likely a reproducible condition.

Ah, well, you live and learn.

Andre Jute

expr

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Re: Rohloff oil colour
« Reply #9 on: April 21, 2010, 09:00:57 PM »
Interesting. Do you use the Cleaner Oil at all during this process?

Yes, sprocket comes off first then I add the cleaner oil. The sprocket goes back on, and then I go off for a short ride in gear 7 (all gears turning in gearbox) then take off the sprocket and drain and leave the wheel resting over a small container to dribble in to. Then measure out 20ml of oil and fill, either by the syringe into the bearing or i tend to use a small laboratory calibration cylinder made from glass ( 0-20ml)

Note: keep a slight angle on the wheel to allow the air to escape from the side of the bearing.

sbseven

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Re: Rohloff oil colour
« Reply #10 on: April 21, 2010, 11:35:49 PM »
Thanks for the explanation, expr.

Just a small point and I'm sure it doesn't make any difference to your process, but it's only gears 3 & 5 that engage all the gear sets. See just below Figure 5 towards the bottom of the following link: http://www.rohloff.de/en/technical/speedhub/efficiency_measurement/index.html

Shaun

expr

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Re: Rohloff oil colour
« Reply #11 on: April 22, 2010, 06:19:50 PM »
Hi Shaun, my mistake sorry yes quite right 3-5. 

Andre Jute

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Re: Rohloff oil colour
« Reply #12 on: May 11, 2010, 10:34:02 PM »
Gentlemen:

You'll remember some clear liquid was twice found under my Rohloff hub gearbox a good long while after I gave the gearbox its annual oil change (the bike did very few miles  over this period because of the filthy weather) and I wondered if it was cleaning oil that hadn't been drained out, and had separated from the new all-seasons oil. The consensus of opinion was that I should drain the hub again and check what came out.

I've now drained the hub and what came out, after several hours with the syringe hanging down, is 8mm of good clean black stuff, clearly all-seasons oil.

Zero separated cleaning oil --- that was a red herring, I now think. The oil change kit I used in January, the only one I had to hand at the time, had leaked in transit, so I put in all the 20ml or so of all-seasons oil I had, and this computes well with what came out in May (12ml stays inside, 8ml comes out, total 20ml); my conclusion is that there was no cleaning oil left in there. What it was that was found on the floor under the bike is a mystery. As Dave said, we're never going to duplicate those circumstances.

Check the logic of what I did next, if you please:

I reasoned that there's 12ml of oil sticking to the gears, a figure mentioned by Andy Blance, plus say 7mm that went back in of what I took out (a little bit stuck to the inside of the syringe tube), so that's at least 19ml of oil in the gearbox.

The hub gets light use on tarmac, certainly no mud-plugging or riding through hub-deep streams. So I reckon that's good enough until the next scheduled service next January, about a thousand miles away.

While I find agreement charming, if anyone thinks this procedure is dangerous to my pocket (There goes the idiot who wrecked an unwreckable Rohloff... don't grow up like him), or you would do different for any reason, please speak out bluntly.

Thanks for your time and wisdom, gentlemen.

Hobbes


expr

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Re: Rohloff oil colour
« Reply #13 on: May 11, 2010, 10:46:28 PM »
Hi Hobbes,

I think what you propose is fine, glad to hear the hub is all ok.

stutho

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Re: Rohloff oil colour
« Reply #14 on: May 12, 2010, 10:19:12 PM »
Hobbes,

All sounds good to me!