Rohloff gear change

[seligsohn]

I have had a Rohloff on my tandem for 13 years.  It functions perfectly and we have covered about 12000 miles.   Every year I make an oil change.   Recent oil changes have led to the oil leaking quite badly but the gear stll functions perfectly.  This time, I came to changing the oil and although I added 25 mL cleaning fluid, when I drained the hub after a mile or so ride, very lttle cleaning fluid came out!   I am leaving it for a few hours to see if any more drains out.   But I am curious to know where the cleaning fluid has gone?!   Very little has leaked out.   I shall continue with removing what cleaning fluid I can   and then add the new oil. Has anyone else using Rohloff had this experience??

[JohnR]

My method is to use the filling syringe to suck the oil out after (a) connecting the syringe (with the plunger half out so the syringe contains some air) to the filling hole; (b) turning the wheel so the hole is at the bottom of the hub; (c) waiting a few minutes for any oil to drain towards the hole then (d) push in the plunger to blow the air in the syringe into the hub and then pull the plunger to try to suck any oil out. I do my oil changes on a warm day so the oil flows better. At my last oil change none of the normal oil in the hub wanted to come out but I extracted as much dirty cleaning oil as I had inserted clean oil.

There's plenty more discussion about oil changes at http://thorncyclesforum.co.uk/index.php?topic=13327.0 .

[PH]

How odd, it you put it in and it hasn't come out it must still be in there!  I think you'd notice if more than a few ml had leaked in a short time. 
You do sometimes get a situation where the pressure differences stop it coming out, I'd be tempted to use another 5ml or so, put it in, turn the wheels in the appropriate gear (Rather than ride it) and see what you can get out. I try and leave it to drain overnight, but in reality I think it's all out in the first couple of hours.
As for the leaking having become worse over time - My oldest hub (2004) is like this, I use the method described in the Thorn booklet of adding the oil and then withdrawing most (I forget the numbers, they're in the pdf) There's not much left in to leak.  When this hub was in my most used bike I had some concern that it was letting water in, it would over time leak more than I'd added. I was considering sending it away for the seals to be replaced, but now it doesn't see so much bad weather I'll probably not bother. 

[Andre Jute]

Every year I make an oil change.   Recent oil changes have led to the oil leaking quite badly but the gear stll functions perfectly.

No need to panic yet. Your Rohloff is protected by what remains of the old running oil and also by the cleaning oil which didn’t come out. The cleaning oil is itself a running oil, prescribed for extreme cold conditions. In future, regardless of what you get out of the box in cleaning oil plus residual old All Seasons Oil, use 16ml of All-Seasons Oil (which is already a third more than Rohloff puts in new boxes) and if the leaking is cured or much decreased, you’ve solved your problem. If the leaking remains at the same level, it would probably be smart at least to call Thorn or even to write to Rohloff in Germany.

But be sure you’re not dealing with the effects of condensation caused by temperature change. I had a case of bad leaking under my bike once, when my Rohloff was new. After I stopped panicking, I tasted the suspiciously clear fluid and discovered it was the result of a change of temperature, condensation, water.

I’ve never heard of a meticulous owner like you suffering a broken gearbox for lack of lubrication. I suppose it isn’t impossible but the likelihood appears to be galactically remote. In any event, it can’t happen to you because the oil that matters sticks to the gears and if the bike is serviced on time, any loose oil sloshing about and perhaps out past seals designed to keep dust out rather than oil in, is surplus to requirements.

Good luck!

[UKTony]

I’ve done a similar mileage from new in benign riding conditions over 8 years and have had no abnormal oil leaks. The hub has had 8 DIY oil changes plus one by Thorn when the hub was converted to disk brake and required a new seal on the non drive side as part of that conversion.

I follow the instructions as per the leaflet that accompanies the Rohloff oil change kits which is also in their owners manual here

https://www.rohloff.de/en/service/handbook/speedhub/workshop/oil-change

Note that Rohloff draw attention that overfilling can increase risk of leaks. MIGHT it be possible that the temptation to put more oil in after a leak is perpetuating the problem? 🙂

Occasionally after inserting the 25ml of new oil I have forgotten to “Draw out approx. 25ml of air to keep the pressure correct inside and therefore, avoid oil seeping back out, when removing the filling tube “ although I haven’t noticed any leakage as a result.

I don’t know if you’ve got the external gear mech version, but not greasing the inside of the box every few hundred miles I’ve read somewhere, might make seepage  from the breather hole in the hollow axle more noticeable?

[CycleTourer]

It's worth mentioning that a country’s official Rohloff service center can do a full cleaning and re-oiling of the hub internals. If you have had the hub for 13 years already and you are worried about the state of the lubrication inside, perhaps you might consider it worth paying for this service, though 12,000 miles is on the low side for a Rohloff.

[mickeg]

... I am leaving it for a few hours to see if any more drains out.   ...

We are waiting to hear.

[Tiberius]

seals designed to keep dust out rather than oil in

Andre. Is that actually true or your opinion?

The reason that I ask is that I'm always surprised at the number of Rohloff owners who complain of oil leaks. Bearing in mind the very small amount of oil inside the hub, it seems to me that the oil seals are very poor 'seals' It makes more sense (to me at least) if they are MAINLY there to keep dust out.

[UKTony]

Page 32 of this document is worth a read.
And I’ve discovered where I read about the need to regularly grease inside the ex box to prevent leaks! (The Rohloff Owers Guide recommends doing this every 500km.)

http://www.sjscycles.com/thornpdf/ThornLivingWithARohloff.pdf

[PH]

And I’ve discovered where I read about the need to regularly grease inside the ex box to prevent leaks! (The Rohloff Owers Guide recommends doing this every 500km.)

I must admit that though I've read this several times, I've never understood it.  The part Rohloff recommend greasing every 500km is the hub side of the pully on the cable box where it attaches to the transfer box, this is to keep it functioning smoothly.  Where does the idea of an oil seal come from?  For oil to leak from this joint it would have already left the hub, trapping it in the transfer box isn't going to do any good. If you open up that box you'll see it's pretty obviously not a route for escaping oil. It might be advantages to grease the interface between the transfer box and hub, maybe this is what Andy Blance was recommending, it's unhelpful that he uses the term EX box without being clear if it refers to the cable box or transfer box, though Rohloff do no better, referring to the same part as "transfer box" or "gear mech", either way it's only the pully on the cable box that forms part of Rohloff's maintenance advice. 

EDIT - There's a video here on how to convert from internal to external mech, the space behind the axle plate is packed with grease (2:25), maybe this is what was meant? Though it makes no mention of oil sealing.
https://www.youtube.com/watch?v=WGNFZjavXcI

[mickeg]

I think most of my oil loss is from the EX box area, that usually has a coating of oil on it.  I have not filled mine with grease, I only have enough grease in it to lube the cable spool.

Even if it was meant to use grease as an oil seal, oil is a good solvent for dissolving grease, so I am not going to try filling up my EX box with grease to stop any leakage.

I think I had some extra oil leakage in the photo, more than normal.  I changed the oil before I got on an airplane and I suspect that the non-drive side was oriented down in the airplane hold for one or both of my flights before I started my tour.

I just wish all this oil leakage landed on my chain instead, there it would have done some good.

[CycleTourer]

I think most of my oil loss is from the EX box area, that usually has a coating of oil on it.

Isn't there a hole inside the Rohloff axle meant to sweat oil? I assume the oil came from there and dripped down onto the EX box area via the quick release, because the QR also gets some oil on it.

[Andre Jute]

The purpose of packing the EXT box with grease is to exclude water from the matching shaft and cable terminations, the brass nut you see bikeside when you take the cover off, on which the hex socket inside the cover at the end of the cables fits in order to change the gears.

I have no idea why these small parts couldn’t have been made of stainless steel.

I fill the EXT box on my bike once a year or every 5000km* with green stuff from Phil, the famous bottom bracket maker in the States, but suspect a good marine grease will do as well. Martin mentioned a brand of marine grease he used on his bikes, though whether for this specific purpose is another matter.

The 5000 above is not a typo for 500. I mean 5000km/3000m. My bike is in undemanding use and rarely more than superficially wet and in the beginning I inspected Phil’s green stuff every 1000km, but now I know it lasts a year in the EXT box, no problemo. Be smart to consider the conditions in which your bike is used before you emulate my practice. In particular, I never ride it through water as deep as or deeper than the hub, and my bike never gets so dirty that I need to take a hose to it because even the smallest farm lanes around here are blacktop.

[PH]

The purpose of packing the EXT box...

I stopped reading there, what part are you talking about?  I thought you were an engineer
The external gear mechanism is made of of two primary parts, a transfer box and a cable box, unless you use the correct terms you're leaving the reader to guess what part you're packing with grease. You may think it's obvious, but we've had long threads before where people are talking at cross purposes.

[PH]

Isn't there a hole inside the Rohloff axle meant to sweat oil? I assume the oil came from there and dripped down onto the EX box area via the quick release, because the QR also gets some oil on it.

That may or may not be the case, I don't know.  I do know that my nutted hub leaks the same amount as my QR ones and it gathers in the same place.