Author Topic: Rohloff chain replacement???  (Read 4218 times)

Inbred

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Rohloff chain replacement???
« on: January 21, 2019, 09:01:38 am »
I own a Thorn Raven Tour and I've been wondering if I need to replace my chain.

According to my Park Tools check checker, inputs well past its best!

I've done a bit of research and there seems to be two schools of thought...

1) Treat it like a deraileur bike and replace the chain when it stretches too far.
2) Ignore the stretching, remove a link, turn back the eccentric bottom bracket and start again.

Any advice?
What do you do?

Thanks for the help 🙂👍



geocycle

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Re: Rohloff chain replacement???
« Reply #1 on: January 21, 2019, 09:19:54 am »
Definitely an 'it depends'!  My approach has been to run it until it is in danger of falling off after the EBB has been adjusted to the max.  I've never been successful in the 'removing a link method' as my particular chain ring, frame and sprocket combination seem to lead to the chain being too tight with a link removed. 

There is no mechanical advantage in changing a chain early unless you want to try and protect the sprocket from wear.  If you leave it too late the sprocket wouldn't necessarily take a new chain, although you could turn it.  My solution has been to run two chains in parallel so they wear evenly with the sprocket.  I typically get about 10,000 miles from this approach.  The chainglider team will get even more.

Personally, I never measure the wear and I wouldn't treat it like a derailleur chain.
 

mickeg

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Re: Rohloff chain replacement???
« Reply #2 on: January 21, 2019, 05:23:22 pm »
I buy the cheapest chains.  Thus, I see no advantage to pushing a chain much farther once it is pretty worn.

Once my chain checker tells me that the chain is worn more than 0.75 percent, I take the chain off and stretch it out and measure it again with a long ruler which is more accurate.  I find that the short little chain checkers usually indicate more wear than is actual, thus the second longer measurement.

I have always replaced a chain at 0.75 percent, but I am starting to think that on my Rohloff bike I might start to push chains to 1.0 percent instead.  But I probably will keep using 0.75 percent for my derailleur bikes.

Since there is a huge variety of different sprocket and chainring combinations, along with different chainstay lengths, you can't compare two Rohloff bikes against each other and say when the eccentric has run out of adjustment it is time to replace.

The only exception to the above is that in winter I might use a chain that is already pretty worn.  I put studded tires on my Nomad for winter riding but I ride very few miles on it.  The de-icing chemicals used on the roads here can badly rust out a chain so once a chain has been used in winter here it is usually time to replace it anyway.  Sometimes when I pull a chain off of another bike because it is worn out, I will set it aside to use in winter on my Rohloff bike.

martinf

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Re: Rohloff chain replacement???
« Reply #3 on: January 21, 2019, 08:15:08 pm »
1) Treat it like a deraileur bike and replace the chain when it stretches too far.
2) Ignore the stretching, remove a link, turn back the eccentric bottom bracket and start again.

With 1, you spend more on chains, but they will be less likely to break. You will also be able to get more mileage out of (expensive) Rohloff sprockets and (usually quite expensive) chainrings. You should probably save maintenance time overall as less need to remove sprocket and chainring for replacement, when fitting a new chain they can be cleaned in-situ (this is easier with hub gears or single-speeds).

With 2, you spend less on chains, but you may end up spending what you save on sprockets and chainrings, which wear faster with a worn chain. Another down side is that a very worn chain can snap, had this happen when towing my trailer, but luckily only a few kms from home.

I have used both methods. Changing at about 0.75 percent enabled me to get a derailleur cassette to last through 4 chains without chain skip on a fairly long tour, of which a significant part was in wet and muddy/sandy conditions.

On my old utility bike with very cheap Sturmey Archer sprockets I used to run the chain/sprocket set until very worn, but with the variant of alternating two to four chain/sprocket sets every 500 to 1500 km (depending on weather) to try and even out wear on the chainring. I would then scrap the whole lot when things felt too worn out, generally with 5000 to 8000 km on each chain and two to four times that on the chainring.

I have now got Chaingliders on most of the family bikes, these seem to keep the chain much cleaner and hence reduce wear. Perhaps more important, they significantly reduce time spent cleaning and lubricating chains. 


Matt2matt2002

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Re: Rohloff chain replacement???
« Reply #4 on: January 21, 2019, 09:45:03 pm »
Interesting comment Martinf.
Re the Chainglider.. I'm a big fan and have had one on my Raven for 4+ years. I don't have any data to prove it but I'm sure it must help considerably reduce wear. All that muck and dirty water flicked up from the road hardly hits the chain.
Sorry to hijack the post but if the OP is interactive in reducing wear then take the Chainglider plunge. Providing your front and rear sprocket are compatible to the Chainglider specs.
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Andre Jute

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Re: Rohloff chain replacement???
« Reply #5 on: January 22, 2019, 10:55:51 am »
These people who throw around big round mileage-per-chain numbers always make feel like I'm littering or something equally antisocial by not getting 12,000 miles per chain.

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Inside a Chainglider there is no visible wear on a 10,000km/6000m Rohloff sprocket, though it must be said the transmission is on it's third chain because a) I am a masher, historically tough on chains, and b) I had to retire one chain very little worn because I fitted a bigger chainring as my health improved (and also because I fitted a centre electric motor which requires a dished chainring to preserve the tread width). How totally outstanding this is -- for me -- can be judged from the 1000m/1600km I used to get on complete set of chain, sprocket and chainring before...

Generally speaking, I buy excellent quality KMC X8  or Y8 chains in bulk at sales by my "local" dealer, Chainreactioncycles, and replace them at about 0.5 percent wear, which in the normal course of events happens at about 4500km (so the bike above would be on it's third chain anyway). Do the better chains protect your sprocket and chainring longer? I have no idea but would hope so because, according to the KMC literature, there are constructional and material differences between their chains, more cutting edge chain tech being introduced the higher up the range. Maybe George's cheap chains are as good up to some wear point x, and if you never exceed that wear point, there is no difference. Note however that I don't go for the X1 at the very top of the range, street price about twice that of the X8, as I don't see that if offers much extra for double the money, especially inside a Chainglider where stainless steel is probably wasted.

My reasoning for running chains only to 0.5 percent wear is that the sprocket (mine is the original-model Rohloff sprocket) could be hard to get off, while a chain replacement is a doddle -- the biggest challenge is to get the Chainglider on exactly as you had it before, so that it will be utterly silent. Even a good quality chain is also the cheapest component in the Rohloff transmission. So I change the chain a bit early and preserve the sprocket and the chainring. See Martin's analysis above of the two possible approaches to chain wear.

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Both my Chaingliders are long since all paid up in extra mileage on chains alone, and again on sprockets (I use stainless or painted steel chainrings and they just don't wear inside a Chainglider). I've come to the conclusion that the Chainglider is the best bargain on a bike, especially if all your cycling life you had an adversarial relationship with chains. I'm at last comfortable with chains, as long as they stay inside my Chainglider.