Rohloff Splined Sprockets (Ease of swapping)

[hedwards]

I've just swopped my threaded sprocket for the new splined type.  I'm now running a 42 x 19 which gives me a very low bottom gear range.  Whilst on a SE Asian tour I will want to swop the sprocket for one which will give me a higher range.

Has any one done this? What tools will be needed? Is it a risky manoeuvre as spares would be difficult if things went wrong?

Any advice would be useful.

Thanks

Harvey

[Harvey, I changed the title of your post to make it more searchable in the future and to avoid apparent duplication with other, related threads. As the new Rohloff splined sprockets gain a user base, questions are beginning to arise about their fitment and compatibility. Posts such as yours -- and the answers that follow -- will likely become a valuable resource for others who follow. Welcome to the Thorn Cycling Forum. Best, Dan.]

[geocycle]

I've not done this yet on my new splined sprocket but in theory you just remove the lock ring. I'd attack with a small screwdriver but I'm sure someone will be here with better advice. I'd guess in moving to a smaller sprocket you will have to adjust your chain length, probably by shortening it by a link.

[mickeg]

I have never done it and have threaded sprocket.

But I have switched back and forth between two chainring sizes, a 44 for use around home and a 36 for touring and for mountain biking with my Nomad.  I set up the chain so that it works with one quick link on the 36T chainring, but if I switch to the 44T I have to add four chain links (three regular links and a second quick link).  And I have to adjust the eccentric to readjust the chain tension.  It is not a change that I want to make often, but I can probably add or remove the links and re-adjust the eccentric in less than 20 minutes.

In my case, I added 8 teeth to the chainring to upsize from 36 to 44, that meant adding four chain links.  If you remove only a few teeth from 19 down to 17 or something like that you might be able to do it without adjusting the number of chain links.

I have not changed the splined cog on a Rohloff, but I have changed them over the years on a Sturmey Archer 3 speed hub.  If it is a similar chore, it is not a big deal.  But if the circlip goes flying, you do not want it in your eye and you do not want it to get lost.

[martinf]

Still running the old Sturmey Archer 3 and 5 speeds on some family bikes.

If the Rohloff splined sprocket works like the Sturmey Archer circlip and sprocket, prise the retaining circlip off the hub while the wheel is still in the dropouts.

Then the circlip can't fly away.

[John Saxby]

Murphy's Law would seem to require carrying a spare circlip or two.

[mickeg]

Murphy's Law would seem to require carrying a spare circlip or two.

If it was me, I would not bother with spares.  The idea to leave it in the frame is a really good idea. If indoors, they are easier to find.

[hedwards]

It's the circlip that worries me in removing the sprocket.  It appears that they are not sold separately, only with the carrier.

[StuntPilot]

The 'circlip' would be a necessary spare part on a long tour with the splined setup. Harvey, the same sprocket removal tool Rohloff Part 8501 is required to remove the threaded sprocket and fit the spliced sprocket (and big spanner and chain whip of course).

I am running a Thorn Raven Tour with 38 tooth Thorn chainring, and a 16 tooth standard screw on Rohloff sprocket.

I welcome this post as I have recently been looking at the feasibility of retrofitting the new splined sprocket at some point in the future. I still have a spare standard 16 tooth sprocket so it may be a while!

My main question about changing to a splined sprocket setup is that I understand that the chain line will change from 54mm to 58mm.
Does this mean I would need to swap my Shimano 68mm x 110mm bottom bracket for a longer bottom bracket or can the new chain line be accommodated using only spacers and chainring bolts?

This is an important question for me as I am considering purchasing a new bottom bracket as my current Shimano UN-52 is getting on a bit.

What do you think folks?

[TheShipwright]

StuntPilot Rohloff have brought out an "S" (S= slimmer I guess) version of their splined carrier which gives same, or very similar, chainline as the screw on sprockets.

I have the S version ready to swap over but haven't got around to it as yet, I need to make a few changes at the same time.

Martinf, on this thread
http://thorncyclesforum.co.uk/index.php?topic=11609.60

posted this link to the S version.
https://www.rosebikes.com/article/rohloff-s-adapter-for-splined-carrier/aid:2668410

I got my S version from SJS but had to ring them as it wasn't listed on their site.

When I get around I'll make some notes on how easy it is to swap the sprocket using the circlip on the splined carrier.

Edited: If people are interested I could measure my new S carrier's circlip?  I would think that they are fiarly standard and could be bought from ebay/amazon etc.

[John Saxby]

Harvey, if getting a spare circlip is a problem, and if you need or feel more comfortable having one, maybe it's worth revisiting the original idea of changing sprockets.

Your current 42 x 19 setup gives you a range of 16.0 gear-inches (low) to 57.5 (11th) to 84.3 (high), assuming a 26' wheel/tire measurement. Do you need a higher range -- will you be lightly loaded? riding on mostly flat terrain? relying on tailwinds? etc.

People have different needs and preferences, and I don't know yours. I manage just fine with a 36 x 17, which gives me these comparable gear-inch ratios: 15.4 - 55.1 - 80.8   These work very well for me -- I use the lowest gear only on steep hills when the bike is loaded. On flat or gentle terrain, I use the upper register almost exclusively, loaded or unloaded.

Offering this suggestion as a way of simplifying things -- hope it's useful.

Cheers,  John

[hedwards]

Thanks.  I suppose I will not really know until tested in the field.  I intend to go to Northern Thailand and Laos where I have been before and know there are hills from hell!, but if I then go south the terrain becomes very flat.  That would be when I would like to change the sprocket.

[StuntPilot]

Thanks Shipwright! I did not know that a 's' version existed. Thanks! That would solve the chain line issue, if the issue did exist with my current setup.

I agree John, I would not probably want to swap the sprocket on tour until it came to the time when I needed to reverse it due to wear on a long tour. Though I could see an easy swap ability being useful when moving between extremes of terrain, such as going from a mountainous region to a flat region on the same tour.

But then where is the fun in reversing the sprocket with the spliced version! Part of the fun was hunting for a chain whip and big wrench, meeting the locals who are intrigued with what you are up to, setting it all up then struggling, sweating and cursing until you got the sprocket to budge!

The 'How to change a Rohloff splined sprocket' video would be much less entertaining!

[mickeg]

The 'circlip' would be a necessary spare part on a long tour with the splined setup. ...

If you really think that the circlip is a necessary spare, it likely is a standard size that a well stocked machine parts store should have for sale.  I am in USA, I do not know if our typical hardware store would have them, but I have seen some stores that have that kind of stuff in stock.

Does anyone have any measurements of it?

...
My main question about changing to a splined sprocket setup is that I understand that the chain line will change from 54mm to 58mm.
Does this mean I would need to swap my Shimano 68mm x 110mm bottom bracket for a longer bottom bracket or can the new chain line be accommodated using only spacers and chainring bolts?

This is an important question for me as I am considering purchasing a new bottom bracket as my current Shimano UN-52 is getting on a bit.

What do you think folks?

I have an intentional chainline error of about 5mm.  I did not want my Q Factor (width between pedals) to be much bigger on my Rohloff bike than on my derailleur bikes, thus I bought a spindle that was 10mm shorter than it should have been for a perfect chainline.  I bought a spare thread on sprocket (before the thin splined version came out) because I did not want to have a chainline that is off by 9mm, but 5mm is not a problem in my opinion.

But if your chainline is spot on at this time, a few mm of chainline error is not really a problem.  That said, the slim version might be best for you if you have a concern.

When you consider that the typical derailleur bike is almost always in operation with a chainline error of over 5mm, that suggests to me that a small error is not a problem.

[TheShipwright]

I've just measured the circlip and it's 36mm internally with a wire thickness of 2.5mm so externally 41mm.

[martinf]

I've just measured the circlip and it's 36mm internally with a wire thickness of 2.5mm so externally 41mm.

Similar to the standard size for Sturmey Archer, many SRAM and Shimano Nexus 7, 8 and Alfine 8 hubs - these all use more or less the same circlip with an internal diameter of about 35 mm (if slightly undersized it will spring open enough to fit on the Rohloff). So it should be possible to find a spare in countries that have a tradition of using hub gears.

But I reckon you are unlikely ever to need a spare so long as you take care when removing. I don't recall ever losing or breaking one in over 40 years of using and maintaining hub gears with this type of sprocket retainer. Rohloff would be even more unlikely, as less need to dismantle the hub for servicing.