Thorn Cycles Forum
Community => Rohloff Internal Hub Gears => Topic started by: TheShipwright on August 25, 2016, 09:59:33 am
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[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.
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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.
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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
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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?
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I'll check my skewer for you when I get home, mickeg.
All the best,
Dan.
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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
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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.
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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 :-)
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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
Nectar of the gods is what came in the containers shown.
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ARGH!!!! I was finalising the the setup of my bike by carry out an oil change and changing the rear sprocket and I damaged the "drive unit" or "driver" (sorry I forget teh exact name), it's the part the sprocket removal tool connects to. The sprocket was REALLY difficult to remove and I had a few attempts at it and think I must not have tightened it enough on one occassion. Possibly a combination of tight sprocket and my poor method.
I've sent it off to SJS after talking to Dave their Rohloff chap and whilst chatting it over I mentioned my potential "oil leaks" and he said "I wouldn't be overly concerned about those, it's not uncommon". As it's now going in for work I'm getting a full service (new gaskets I think are included) and the new sprocket style carrier installed.
I "may" have over reacted and panicked with my decision regarding changing to the new style sprocket carrier but I assume I can always remove it and go back to a traditional styel screw on.
FYI Dave said turn around is circa 3 days for a full rebuild at present so let's hope the Parcelforce get a move!
Cheers
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I "may" have over reacted and panicked with my decision regarding changing to the new style sprocket carrier but I assume I can always remove it and go back to a traditional styel screw on.
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Apparently the thread on sprockets will no longer be made, only the new style. For chainline reasons, I want to stay with the old style, I recently bought a spare thread on one. Many of my miles are on derailleur bikes, plus I don't put on the high mileages that some people do. Thus, I think I have a lifetime supply of oil and sprockets.
If you might be able to use your old one in the future, make sure you tell the shop that you want that part returned. Most shops discard old parts.
I found it pretty easy to get my sprocket off after three years. I only took it off just to make sure I could get it off, not for some other reason. The key is a good size chain whip and long wrench. And a good coating of grease on the threads when you put it back on. Or, if you have a monstrous vice bolted to a robust work bench, maybe the wrench is not that critical, but I prefer a really big wrench over the vice.
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I read about the threaded batch but I'm guessing it only matters to peopl running chaincases and who are wedded to 54mm chainlines.
I'm going plop some spacers on chainring and maybe budge my EBB over a bit as well.
Regarding the return of the old sprocket, I've put it on the note that i attached to the wheel so hopefully it will come back.
My sprocket I think was stuck fast, I suspect that previous owner and previous previous owner had both tried and given up as it was quite worn.
thanks for the info
gerry
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ARGH!!!! I was finalising the the setup of my bike by carry out an oil change and changing the rear sprocket and I damaged the "drive unit" or "driver" (sorry I forget teh exact name), it's the part the sprocket removal tool connects to. The sprocket was REALLY difficult to remove and I had a few attempts at it and think I must not have tightened it enough on one occassion. Possibly a combination of tight sprocket and my poor method.
I "may" have over reacted and panicked with my decision regarding changing to the new style sprocket carrier but I assume I can always remove it and go back to a traditional styel screw on.
FYI Dave said turn around is circa 3 days for a full rebuild at present so let's hope the Parcelforce get a move!
Cheers
Your in good company, I did exactly the same and my hub is also currently with sjs. I've replaced the sprocket several times but this time it stuck fast and the rohloff tool slipped damaging the driver. On Dave's suggestion I'm going splined. I'll report back next week after a bike less week in Provence!
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I am surprised that Dan has no oil film on his skewer, as I assumed an oil film on the skewer is normal.
Hi mickeg!
Sorry for the delay, I was away.
I just removed my skewer and here is how my hub looks. The skewer is not totally dry...wiping the full length of the shaft did produce a little "color" on the ridges of the paper towel, but not enough to soak in. No oil has leaked from the axle nor onto the adjusters. My external shift-box is pumped full of Phil Waterproof Grease, and this has not migrated either.
I hope the pictures are helpful
Has more oil migrated from your hub since tightening the screws?
All the best,
Dan.
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I just removed my skewer and here is how my hub looks. The skewer is not totally dry...wiping the full length of the shaft did produce a little "color" on the ridges of the paper towel, but not enough to soak in. No oil has leaked from the axle nor onto the adjusters. My external shift-box is pumped full of Phil Waterproof Grease, and this has not migrated either.
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Has more oil migrated from your hub since tightening the screws?
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It is clear that my hub loses a lot more oil than Dans.
And to reiterate from before, I use the 15ml theory instead of the full 25ml at oil change time. So, am not really overfilling it.
I have not ridden my Rohloff bike since I posted my last comment above with the skewer wipedown, I regularly ride about four or five bikes a year and have been riding my Sherpa for the last several weeks. I will ride the Rohloff bike on Thursday as I will want to use the dynohub powered light to light up a long tunnel on that day. But my tightening of the screws was so minimal, that I would be quite surprised if that makes things tighter. They were already quite tight, so each screw was turned maybe only a few degrees.
There are a couple paper thin gaskets on that side of the hub, I might take a look at them next time I have the wheel out of the hub. I will probably be putting on studded tires in Nov or Dec, so will likely have the wheel out in a few months if not before. I just hope I do not damage any gaskets in the process.
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Dave (the Rohloff man at SJS) has just phoned me to say that my hub has been repaired and is on it's way back to me (hoorah). All gaskets have been replaced (along with with my new style sprocket carrier and new sprocket) so when it's back and being used I'll report on any "misting/leaking" etc.
Big thumbs up from SJS and specifically Dave re the speed of service and their customer service.
Dave also reported that the internals of the hubs also looked in good condition, which is re-assuring as I'm never likely to see the inside of the hub!
Also I rang back to ask Dave about adding chainring spacers and I got Andy on the phone. Andy's opinion was not to worry about the spacers to bring it out to 57-58mm just run it at 54mm.
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Also I rang back to ask Dave about adding chainring spacers and I got Andy on the phone. Andy's opinion was not to worry about the spacers to bring it out to 57-58mm just run it at 54mm.
I wanted a narrower Q factor than a perfect chainline would have produced. Thus, I bought a bottom bracket spindle that is about 10mm shorter than a perfect chainline would have dictated, that means my chianline is intentionally off by 5mm. So I am pleased to hear that Dave thinks small error is unimportant.
But I did not want my chainline error to grow from 5mm to 8 or 9mm with the new system, so I bought a spare thread on sprocket while they are still available.
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very wise mickeg!
I now have 4 of them as I had planned to do my ration experimentation with the screw on version, hence my comment upthread about "panicking" and getting the new style sprocket carrier installed maybe a bit too quickly.
What do people think the consequences of having the chainline out by 3/4 mm will be?
Noise and premature wear?
Thanks
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What do people think the consequences of having the chainline out by 3/4 mm will be?
Noise and premature wear?
Thanks
By 3/4mm do you mean three quarters of a mm or do you mean 3 to 4mm?
I did chainline calculations for my chainline before I bought the bottom bracket for my Nomad. If I was going to worry about 5mm chainline error, I would have bought the right spindle length bottom bracket, but I felt that a 5mm chainline error would not be noticeable. Think about it, most derailleur bikes have more than a 5mm chainline error most of the time.
If I have any excess noise from that or excess wear, I have not noticed it.
A local charity received a bunch of new KMC chains from a major bike manufacturer. These chains had been installed but were removed from bikes that had defective frames. The charity sold them for $5 USD. I bought several. It will be several years before I worry about chain wear.
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What do people think the consequences of having the chainline out by 3/4 mm will be?
I try and get chainline about right, but have sometimes run hub-gear bikes with up to at least 8 mm off the chainline without noticing any ill effects.
As Mickeg says, chainline is much worse a lot of the time on derailleur bikes. I suspect having enough slack in the chain is even more important if the chainline isn't spot on, and it might be better to use a flexible derailleur chain rather than one of the specific hub-gear chains. That said, I was using 1/8" specific hub-gear chains.
Chainline might be more important if using a Chainglider like I do now on 3 of my hub-gear bikes, but for me the main issue with the Rohloff splined sprocket carrier is that it probably puts the sprocket too close to the seatstay to fit a Chainglider without modification.
So like some others I have bought 3 spare screw-on sprockets, which should be enough for at least 30,000 kms of riding, probably much more.
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I have now gone splined!
My chain had run out of adjustment and the new chain would not run smoothly on the worn teeth so I needed to reverse my sprocket. I've done this lots of times before but this time the rohloff tool slipped and damaged the 'driver' in the hub (the part where the tool sits). I clearly didn't tighten the skewer that retains the rohloff tool enough. So, SJS replaced the driver for me and we agreed to change to the new splined system. The results are below, hope these help envisage what the change involves. Ignore the scratches on the hub (an unfortunate incident with barbed wire!)
It does sit a few mm further out from the hub (see side profile). There is clearance in my RST frame but it is relatively tight. Note, I wasn't able to run a chainglider properly before the change and there definitely would not be room now.
It runs fine and I cannot see any significant difference in the chain line. Overall, I'm happy that the next change will be easier!
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Thanks Geocycle.
I too have had my hub back but due to a little postal hishap I haven't actually used the hub yet as I need a new OEM2 axle plate.
That's a good idea adding some snaps for others so here is my recently mounted (but unused hub) with the new carrier style sprocket. Regarding chainline, I couldn't resist making some spacers for my chainring at the front to move the chainring out a bit further, probably because I couldn't ride it and wanted to tinker!
I calculated that the centre of the new sprocket was 9.5mm from the inside my 135mm spaced dropouts, resulting in a 58mm chainline, which conventiently coincided nicely with the thickness of the alu I used to craft my chainring spacers.
Edit: I've measured properly now and it is actually 10.5mm from inside the dropout meaning that it is a 57mm chainline.
Enough wittering here's my snaps in case they help others.
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Thanks for the photos.
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If anybody needs anything else measured or snapped pls just ask.
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Thanks for the photos. A picture makes all the difference.
I have a question: What holds the sprocket in place? That is, what stops it from sliding off towards the right side of the bike? Is it just the friction of the splines? Or is there a retaining clip?
Thanks,
DaveS
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David, I've not taken my new sprocket off yet but my understanding is that there's a large'ish circlip holding the sprocket it place. The Alfine/Nexus and also some SA hubs I think use the same system if you've used any of theses hubs.
The Alfine/Nexus circlips I always found quite tricky, I always managed to get them off and back on again without losing the circlip or an eye!
I guess the idea is idea is that the sprocket is more easily user replaceable. I mentioned to Dave at SJS that as the carriers could potentially be on longer than the threaded sprockets, I.e. they could see many new style sprockets wear out, then if a carrier had to come off it would be a lot more difficult. His reply was that yeah in theory but most users will never remove one and they're Teflon coated to make removal easier and lastly probably someone like him would remove the carrier, i.e. someone who has training, a workshop and experience.
Good luck
Edit: Here's an image I found helpful when researching the splined carrier.
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I suspect most Rohloff owners do not have a good chain whip in their collection of tools. Or the really big adjustable wrench. Thus circlip removal to swap a sprocket is likely a big advantage to those owners.
When I pulled my sprocket off after three years, it was primarily to see how tight it was because I had read on this forum that they can be hard to remove. I had no problem at all in removing it, but I used copious grease when I first installed it and I own the big wrenches that make the job easy. I can see where smaller shorter wrenches could make it a more difficult task.
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Regarding the chain alignment; I recently shortened my chain and adjusted the BB.
It slides from side to side so how was I supposed to make sure the chain ran true?
I did it by sight but is there a better way?
Isn't this alignment problem what is being discussed here due to the new rear cog sitting further ' out'?
Matt
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Regarding the chainline, I admit to being a pedant! Various sources have said running the chainline out of aligment by 5mm or so is nothing compared to what a regular externally geared chain can accomodate. If you want to measure here's how I interpret it from Sheldon B, I measure the width of my seatube divide by 2. Measure from the side of the seat tube nearest the chainring to the centre of the chainring and add the half of the seat tube measurement. so in my case my seat tube is 28.8 mm and from the seat tube the centre of chainring is now 42.5mm so 42.5 + 14.4 = 57mm the magic number for splined carrier.
At the hub, 135mm (hub oln) divided by 2 = 67.5mm. Measure from the inside of your rear DO to the centre of sprocket and subtract from 67.5mm. In my case I measured 10.5mm from DO to centre of sprocket so 67.5mm - 10.5mm = 57mm.
http://www.sheldonbrown.com/chainline.html
Re the sprocket being further out then yes you're correct, I damaged my hub and when repaired opted to have the new splined carrier installed which subsequently moved the chainline out a few mm, I think from 54mm to 57mm. As it transpires my previous chainline was out by a few mm so on the splined carrier sprocket it was out even further out but as I've said I'm a pedant.
Good luck
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FYI, in response to a query I had, Dave Whittle has just confirmed that the old style screw on sprocket removal tool also works for removing the new splined style "carrier", should you wish to remove the carrier.