Rohloff drivetrain wear: when to replace chain, sprocket, chainring?

[Andyb1]

Hi Martin,
I think that the motorbike chain lube you have quoted would be fine on a modern motorbike chain, which is what it is designed for, keeping the side plates rust free and the roller / sprocket interface lubed - but I don’t think it would get into the rollers of a cycle chain.   The loads and speeds that a motorbike chain operates at are obviously a lot higher than on a cycle - hence it is important to keep the roller / sprocket interface clean and lubed to stop wear and heat build up.  Motorbike chain lubes also keep the O rings ‘damp’ to help reduce friction when the links move as they go around the sprockets.  It is surprising how hot an un-lubed motorbike chain can get!

I have one motorbike with a chain (I prefer shaft drive) which is a low powered 411 Royal Enfield Himalayan, used on and off road.  The chain is the OE one with O rings but I have fitted a manual chain oiler to drip ATF fluid onto the chain to ‘wash’ dust off.  I have tried using heavier gear oils but they do not clear the dust - ATF is very thin.

I have sprayed motorbike chain lube onto my cycle chain in the chainglider once.  A spray lube is quite thin until it dries, and maybe some lube got into the rollers but most seemed to go onto the outside of the chain which is not really where I wanted the lube to go!  So personally I now use a thin ‘wet’ cycle oil on my 2 bikes that have chaingliders and drip it onto the rollers.

[martinf]

I have tried various motorcycle lubes at times in the past. Anything that worked reasonably well on a bicycle chain in wet weather also picked up a lot of dirt, so not good on an exposed chain. It might be different under a ChainGlider.

I think that the motorbike chain lube you have quoted would be fine on a modern motorbike chain, which is what it is designed for, keeping the side plates rust free and the roller / sprocket interface lubed - but I don’t think it would get into the rollers of a cycle chain.

The technical data sheet for MOTUL MC CARE C5 Chain Paste says "All types of chains: standard and with O-RING, X-RING, Z-RING.", so I'll give it a try.   

I have one motorbike with a chain (I prefer shaft drive) which is a low powered 411 Royal Enfield Himalayan, used on and off road.  The chain is the OE one with O rings but I have fitted a manual chain oiler to drip ATF fluid onto the chain to ‘wash’ dust off.  I have tried using heavier gear oils but they do not clear the dust - ATF is very thin.

My brother has a Scottoiler system on his off-road motorbike. This drips oil (Scottoiler brand) onto the chain. Works for him, but not on a bicycle (I tried).

So personally I now use a thin ‘wet’ cycle oil on my 2 bikes that have chaingliders and drip it onto the rollers.

I do the same on my own bikes when the KMC factory lube has worn off. Quick and easy to do.

But dismantling/refitting the ChainGlider can be challenging for a user with no mechanical aptitude.

Under a ChainGlider the slightly sticky factory lube on KMC chains works for a long time, but after a lot of use in salty and/or wet conditions it eventually needs renewing with something. So I need something that lasts for a few weeks even under very wet conditions.

[Andyb1]

I don’t remove any of the chainglider to oil the chain, I drip oil onto the top of the lower run of the chain just in front of the rear sprocket while pedaling slowly backwards.

The rear section comes off easily enough to remove the wheel and I removed the front part at 5000 miles in case the insides needed cleaning (there was a little grease).  The next time I swop chains around I will try and pull the replacement through with the existing chain.

[Chris2020]

You might consider measuring your chain later.  The cheap small chain checkers are not very accurate, but you can measure the length of an entire chain when it hangs from a hook.  One link is a half inch when new, thus 100 links is 50 inches from center of pin to center of pin.  If it is 50.5 inches, that is one percent elongation.  I think on a Rohloff bike replacing the chain when you are a bit over one percent elongation is a good time to replace it.

In case you were wondering. Assuming your method is correct ( which I am), and my maths and measurements are correct ( which I am less certain of) the chain is at ~1.8% elongation.
 

[Andyb1]

Was the chain still operating OK with 1.8% elongation?    No slipping or roughness?

[Chris2020]

I thought it was still running fine. It was getting rather loose and the only issue had been the chain coming off, even that was only a couple of times in the last few months. It was not going to get better though and did tend to be at the most inconvenient moments…

[Andyb1]

Thanks for the info Chris. If it could be tightened (eg by shortening it by one link or by half a link) then it would probably not fall off…….so I wonder how much elongation a chain can take and still be safely useable?

Sprocket wear would obviously also increase but I guess the sprockets could be successfully flipped and work with a new chain while the teeth still had flat ends.

Edited to add
Industrial chains appear to be designed to run to 3% elongation……so 1.8% is only just over half worn!

[PH]

Not my image, but it hasn't been posted in a while and it makes me smile, this is what a worn out sprocket look like 



https://www.swedentoafrica.com/drc-part-3-back-to-kinshasa/

[Andre Jute]

Re the bicycle lube and the method of applying it.

The method of running a bead of oil at side of the roller where it meets the side plate, on only one side, was brought into cycling by the late Sheldon Brown, presumably from motorcycle practice. I say presumably because I never saw Sheldon mention where he got it. On one side only because you want the oil to enter the roller on one side and flow through and out the other side, carrying the gunge out with it. Applying oil to both sides may/will form an airlock and the oil and gunge will whip itself into a grinding paste, precisely what you're trying to avoid.

As noted above about motorcycle chains by a couple of contributors here, I also saw the racing mechanic who looked after my big Laverda lay a bead of oil down the centre of the motorcycle chain; since he was ex-factory, I think we may safely conclude it was the correct procedure, approved by the designers of the bike.

Something else which I don't remember ever seeing mentioned here, is that Rohloff sells its own chain oil in a little 50ml squeeze bottle with pointy tip, ideal for applying a bead at the juncture of rollers and side plates. The actual oil is honey-colored but flows much more easily than cold honey, more like heated honey. Fifteen or so years ago, when I bought half a dozen or a dozen little bottles with my Utopia-Velo Kranich, it cost less than a fiver per bottle. Each little bottle would go a very long way. I'm still on my first bottle, having given some away, because there was no place for periodically-added lube in the zero maintenance bike I was developing. This oil replaced the wet wax I used previously, which irritated me by lasting only about a hundred miles per application, though it was a clean method, working by rolling up dirt in little balls of pale grey wax which would fall off inside the big ole Dutch chain cases I used before the Country and the Chainglider: the wax marbles were just shaken out of the bottom half of the chain case. The Rohloff chain oil is a persistent sticker; if you use it as sparingly as you're intended to, you'll never see a drop proving that gravity exists.

[martinf]

I also saw the racing mechanic who looked after my big Laverda lay a bead of oil down the centre of the motorcycle chain; since he was ex-factory, I think we may safely conclude it was the correct procedure, approved by the designers of the bike.

The method I use on bicycle chains (when I oil them). Followed by wiping off any excess with a rag if I put a little too much on.

Something else which I don't remember ever seeing mentioned here, is that Rohloff sells its own chain oil in a little 50ml squeeze bottle with pointy tip, ideal for applying a bead at the juncture of rollers and side plates.

The Rohloff chain oil is a persistent sticker; if you use it as sparingly as you're intended to, you'll never see a drop proving that gravity exists.

Rohloff also sell (sold ?) their chain oil in 1 litre bottles. As I maintain a lot of bicycles I bought a litre a decade or so ago, it will probably last me for the rest of my life. The Rohloff chain oil is a bit sticky, but still gets washed off eventually in very wet conditions. And picks up dirt like any other wet lube when used outside a Chainglider.

I have a litre bottle of a lighter oil, called Morgan Blue Summer oil when I bought it, which works well in clean, dry conditions as it is less sticky. Don't use it much now, I used to put it on derailleur bikes that I only rode in good weather, the only derailleur bike I have now is one of my Bromptons and that is used in all weathers.   

This oil replaced the wet wax I used previously, which irritated me by lasting only about a hundred miles per application, though it was a clean method, working by rolling up dirt in little balls of pale grey wax which would fall off

I tried two methods using wax, the one where you melt the wax and put the chain in the melted wax and then hang it up to dry, also the easier way with a water-based wax emulsion applied to the chain on the bike. Cleaner than anything else, but no good if used in a rainy climate as it doesn't protect the chain for very long.

______________________________________

In my opinion, the best chain lubricant under a ChainGlider is the factory lube that comes on KMC chains when they are new, at least the ones designed for hub gears/single speeds. This lasts for a very long time inside a ChainGlider. But it does eventually wear off/wash off in very wet or very dirty conditions. On an exposed chain, it picks up dust if used off road in dry conditions and, like anything else, it picks up muck if used in wet conditions.   

[mickeg]

You might consider measuring your chain later.  The cheap small chain checkers are not very accurate, but you can measure the length of an entire chain when it hangs from a hook.  One link is a half inch when new, thus 100 links is 50 inches from center of pin to center of pin.  If it is 50.5 inches, that is one percent elongation.  I think on a Rohloff bike replacing the chain when you are a bit over one percent elongation is a good time to replace it.

In case you were wondering. Assuming your method is correct ( which I am), and my maths and measurements are correct ( which I am less certain of) the chain is at ~1.8% elongation.

For 22,000 km on that chain, I am not surprised at 1.8 percent elongation.  I mentioned before that your sprocket looked very good for that kind of distance, and now I am even more impressed by the lack of wear on the sprocket. 

Chain elongation occurs on the links with outer plates, not on the links with inner plates.  In your case that does not matter because your sprocket has an odd number of teeth.  I believe that Thorn always installs sprockets with an odd number of teeth on their bikes.

Rohloffs when new come with sprockets with an even number of teeth.  I assume they still come with 16, but I would not be surprised if they have changed.  I bought my Rohoff hub from a seller other than SJS, mine came with 16 teeth. 

I am not saying one method is better than the other, just that they are different.  I do not believe that Thorn has ever explained why they do it the way they do, but I suspect it is because then all teeth wear the same way.  And then when you put a chain on the sprocket after a repair, it does not matter which links go on which teeth.  But since I have an even number, I need to be careful about that. 

I have shown these photos a few times on this forum, attached.  I took these photos six years ago just before I flipped my sprocket, which is why my sprocket is so clean.  Note that one of the sprockets has a small notch cut in it, I am always careful to make sure when I put a chain on the sprocket that an outer plate link goes on the notched sprocket.  I also added some yellow paint to make that tooth easier to find when dirty. 

A chain and sprocket wear together when you have an even number of links.  And since only the links with outer plates elongate, that is why every other tooth on my sprocket is more worn, that is to match how the chain and sprocket wore together.  I have replaced the chain several times since I built up that bike, but I never replaced or flipped the sprocket.  Thus my sprocket represents several worn out chains.

It is very hard to look at a sprocket and make a good estimate on how much metal is no longer there, but if you look at just the third attached photo, when you consider that each tooth used to be exactly above the round hole below it, if you only look at one tooth with the underlying hole, you can see that the tooth is slightly offset to the right of the hole, that is because some of the metal on the left side of the tooth is now gone. The tooth on the left is even more offset from the hole below it than the tooth on the right, that is because a lot more metal has been worn off of the tooth on the left.

With that in mind, I reiterate that your sprocket looks extremely good for that much chain wear, your sprocket for reference is at this link:
https://thorncyclesforum.co.uk/index.php?action=dlattach;topic=15698.0;attach=21713;image

I have no idea why your sprocket looks that good, it should not.

Off topic - my chainline is not perfect, that is by choice, I wanted my Q factor (width between pedals) narrower on my Rohloff bike to match my derailleur bikes.  The first and second attached photos show different sides of the sprocket, one side has more wear on the sides of the teeth that had inner plate links than the other photo because of this slight off-line chainline.

I do not keep track of how many miles I get on each chain.  I frequently ride four or five different bikes.  Only my Nomad Mk II is a Rohloff bike, the other bikes are all derailleur bikes.  And there are many years when my Rohloff bike gets less than 500 miles on it.  I replace the chains on my derailleur bikes when they are at 0.75 percent elongation.  Thus, I go through a lot of chains on my derailleur bikes. 

I hate to throw out chains with only 0.75 percent wear when I often push my Rohloff chains to over a full percent.  So, starting a few years ago, I now put my 0.75 percent worn chains onto my Rohloff bike to get some more wear out of each of those chains before I discard them.  I probably am the only one that does this, but I am sure it is quite rare for most Rohloff bike owners to also have a supply of chains worn out on derailleur bikes to only 0.75 percent elongation.

That said, I am now planning a bike tour for my Nomad this year that is roughly a thousand miles.  I have been wondering if I should put a 0.75 percent worn chain on it to start my tour, or a brand new chain with no wear.  But I have a few weeks to make that decision.