What chainring and rear cog for Rohloff?

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Billy007
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Re: What chainring and rear cog for Rohloff?

Postby Billy007 » 21 Dec 2020, 6:17pm

tommydog wrote:
Billy007 wrote:
Reading with interest other contributors' valuable experiences on this thread, I think I would rather have as little gap as possible between the chain glider casing and the chain ring to keep crud out. When I remove the glider from my bike the chain is very clean. The reason I bought the Chainglider was to keep the chain clean and minimise maintenance which it has done. A little drag at the start was a little irritating, but once I put a few miles on the bike it gradually disappeared. I suppose if you were that bothered you could take the ring to a machine shop and they could take 0.5 - 1mm off the thickness of the Thorn chain ring where the Chainglider casing sits. Possibly.


You may be interested to hear that I heard back about Specialities TA BMX Chain ring, and they confirmed that it is 4mm thick. Therefore this may work very nicely with the Chainglider for a relatively tight fit. It's thicker than the Surly and the Ebay listing, but 1mm thinner than the Thorn. I am very tempted to get it:

https://specialites-ta.com/bmx/330-1536 ... ure,44-dts

I have no experience of Specialties stuff, but have read a few positive things about them. Do you think it's worth a punt, as on paper it looks like it may work quite well with the Chainglider?


It doesn't seem to be a single speed specific chain ring, but one for 7-11 speeds which typically use narrower chains than single speed set ups meaning the teeth might be thinner and your chain might be a bit too wide for it, although it would probably still work fine but longevity might be reduced. But I might be wrong. In any case you need to get your skates on as TA are French and it might well be that there would be further taxes additional charges to pay after 1st Jan 2021 above the 56.3€ it currently costs in the basket or they might decide not to sell it to you as you are in the UK. It is quite a bit more expensive than other options.
I don't remember taking quite so long to decide which chain ring to buy for my bike. Are you usually quite so decisive, an impulse buyer?

tommydog
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Re: What chainring and rear cog for Rohloff?

Postby tommydog » 21 Dec 2020, 6:31pm

Billy007 wrote:
It doesn't seem to be a single speed specific chain ring, but one for 7-11 speeds which typically use narrower chains than single speed set ups meaning the teeth might be thinner and your chain might be a bit too wide for it, although it would probably still work fine but longevity might be reduced. But I might be wrong. In any case you need to get your skates on as TA are French and it might well be that there would be further taxes additional charges to pay after 1st Jan 2021 above the 56.3€ it currently costs in the basket or they might decide not to sell it to you as you are in the UK. It is quite a bit more expensive than other options.

I don't remember taking quite so long to decide which chain ring to buy for my bike. Are you usually quite so decisive, an impulse buyer?



I emailed them and they replied that it is definitely compatible with the KMC E1 Ept Chain that I use here:

https://www.amazon.co.uk/gp/product/B07 ... UTF8&psc=1

They also said that it would be perfect with the Rohloff. Although, I guess they could be trying to fob me off for a sale!

As for my shopping habits, I am definitely not an impulse buyer! I tend to scrutinise everything in minute detail! A few days to choose a Chainring is nothing by my standards! I recently had a new car and spent about a year agonising over everything! Never been one of those people that can ever make a decision quickly.

Just one other thing I was wondering about the Hebie chainglider, how does it cope if your bike is immersed in water above the chainline? I know it has drain holes, but I guess it still may trap excess water. I say this, as there is a ford, and also flooding on one of my routes, and it gets quite deep when it rains. It often comes above the chain line.

PH
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Re: What chainring and rear cog for Rohloff?

Postby PH » 21 Dec 2020, 9:21pm

jb wrote:Actually a 50t chainring with a 16t sprocket gives you a 22 ins gear which is low enough for anybody on the road, and a top gear of 120

22 isn't low enough for me and I'd find a 120 redundant. Why not let people decide for themselves what gearing they want?

Billy007
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Joined: 15 Apr 2020, 8:56am

Re: What chainring and rear cog for Rohloff?

Postby Billy007 » 21 Dec 2020, 10:15pm

PH wrote:
jb wrote:Actually a 50t chainring with a 16t sprocket gives you a 22 ins gear which is low enough for anybody on the road, and a top gear of 120

22 isn't low enough for me and I'd find a 120 redundant. Why not let people decide for themselves what gearing they want?


Depends on the gradient of the road and the weight you might have on your bike, not to mention your own weight.

Brucey
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Re: What chainring and rear cog for Rohloff?

Postby Brucey » 21 Dec 2020, 11:19pm

interesting that the TA BMX chainring is made using a 4mm thickness blank; I guess it is somewhat 'beefed up' vs a standard chainring then. Still too thick (on paper) for a chainglider.

FWIW chainring teeth vary in width more than you might expect. With any given chain type those for derailleur use are very commonly narrower than those for use with the same chain in a singlespeed system. [However 1x and MTBs can be special cases.] Also the tooth profile varies. So a BMX chainring should have full height teeth, full profile, and the teeth can be as wide as will fit inside the chain. Anytime there is no spring-loaded tensioner you just can't get chainsuck; the chain will be forcibly pulled off the teeth even if they are covered in dirt or burrs. The same amount of dirt could cause chainsuck even with thinner teeth in a derailleur system.

3/32" is 2.38125mm. No 3/32" chainring or sprocket is quite that width. In practice it (for 6/7/8s systems) goes from 2.0mm up to about 2.2mm (for singlespeed chainrings). [ Similarly 1/8" chainrings and sprocket teeth are rarely more than 3.0mm thickness, even though 1/8" = 3.175mm].

9/10/11s chain is actually specified as 11/128" chain, i.e. it is 2.1828125mm internal width (about 0.2mm narrower internally than 3/32" chain). This means that 11s chain won't fit (at all) on some unworn 3/32" SS chainrings that are not 11s compatible, and those that are, are probably around 2.1mm thickness at most. And 9/10/11s derailleur chainring teeth are invariably 1.9mm or slightly less in thickness. If you try and run a 9s chain on a 2.05mm thickness ring (with full tooth profiles), as a middle ring on a triple, it simply won't shift off that onto the innermost chainring.[DAMHIKT]

There is also sometimes a difference between chainring and sprocket thicknesses, chains etc for road bikes vs those for MTBs, presumably because of the mud/chainsuck possibilities.

So there is plenty going on if you choose to look into it; what surprises me is there are not ore problems reported than there are; often by the time an 8s chainring has been used a while, the teeth are narrower than they started out and will actually work OK with 9/10/11s chain.

FWIW if you dunk your chain in water, any chaincase will help hold it inside. I would suggest that if it is river water it is likely to be a lot less harmful than water than might be salty (eg from gritted roads or the sea). Even so I would recommend using a water-displacing spray lube on the chain and having wiped it (and any remaining water ) off then using a good quality chain lube.

If you have broken chains in the past then this could easily be at least partly caused by corrosion; corrosion (or corrosive conditions at least) can greatly increase the chances of cracking in hard steels, and most chain failures these days seem to be caused by cracks in the sideplates.

cheers
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jb
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Re: What chainring and rear cog for Rohloff?

Postby jb » 22 Dec 2020, 10:05am

PH wrote:
jb wrote:Actually a 50t chainring with a 16t sprocket gives you a 22 ins gear which is low enough for anybody on the road, and a top gear of 120

22 isn't low enough for me and I'd find a 120 redundant. Why not let people decide for themselves what gearing they want?

People can have whatever they want its just that I find that much below 22 you start to get a decided spongy soggy feeling to the pedaling action which can offset its advantage. But the OP specifically said he wasn't interested in the three lowest gears so they may as well go on the high end even if they are rarely used.
Cheers
J Bro

tommydog
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Re: What chainring and rear cog for Rohloff?

Postby tommydog » 1 Jan 2021, 11:29am

Good news, I have just found a 5 arm 130 BCD crank at the bottom of my spare parts bin. The 130 BCD crank will give me more options for larger chainrings that are compatible with the Hebie Chainglider. I could therefore go for one of the larger Surly rings in my desired size. But when doing some research, I came across a British company called bikepunx - Has anyone heard of this company, or know if their stuff is any good? They seem pretty reasonably priced and sell 3mm thick stainless steel chainrings. 3mm is bang on spec for the Hebie Chainglider. They list up to 47t in 130 BCD on their website, but when I emailed them they said they could also do a 48t Chainring. This is what I am considering:

https://www.bikepunx.com/5-x-130-bcd-st ... 1822-p.asp

They list if for 1/8" chains. On Rohloff's website they say 1/8" chains are compatible with their cogs, but they go on to say they don't recommend it. But I note that KMC do a dedicated 1/8" cog for Rohloff - so maybe that would be a good option?

https://hollandbikeshop.com/en-gb/bicyc ... ck-639383/

Brucey
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Re: What chainring and rear cog for Rohloff?

Postby Brucey » 1 Jan 2021, 11:34am

does a 1/8" chain fit inside a chainglider?
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ElCani
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Re: What chainring and rear cog for Rohloff?

Postby ElCani » 1 Jan 2021, 11:40am

Brucey wrote:does a 1/8" chain fit inside a chainglider?


It seems to in mine.

tommydog
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Re: What chainring and rear cog for Rohloff?

Postby tommydog » 1 Jan 2021, 11:52am

Brucey wrote:does a 1/8" chain fit inside a chainglider?


There seems to be a mixed opinion on this. I have read posts on other forums where people say they are running a 1/8" chain with the Hebie, but then other posts report problems. On the Hebie product sheet, the only information they give is 9mm for maximum width of chain.

ElCani wrote:It seems to in mine.

Out of interest what brand / model of 1/8" chain are you running with the Hebie?

On another note, does anyone know anything about bikepunx? For me it's a bonus that it's a British company, although I have no idea how good their products are? There seems to be a lack of reviews on them.

ElCani
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Re: What chainring and rear cog for Rohloff?

Postby ElCani » 1 Jan 2021, 12:02pm

It’s a KMC, but I can’t remember which!

slowster
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Re: What chainring and rear cog for Rohloff?

Postby slowster » 1 Jan 2021, 1:11pm

tommydog wrote:On another note, does anyone know anything about bikepunx? For me it's a bonus that it's a British company, although I have no idea how good their products are? There seems to be a lack of reviews on them.

See the thread below on Singletrackworld from 3 years ago.

https://singletrackworld.com/forum/topic/who-makes-steel-chainrings-in-uk/

tommydog
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Re: What chainring and rear cog for Rohloff?

Postby tommydog » 1 Jan 2021, 4:50pm

slowster wrote:See the thread below on Singletrackworld from 3 years ago.

https://singletrackworld.com/forum/topic/who-makes-steel-chainrings-in-uk/


Thanks, I did see that earlier, however there seems to be a lack of reviews on their products. I don't think many people have heard of them. I may just take a punt on one, as I do like the fact they are British made.

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speedsixdave
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Re: What chainring and rear cog for Rohloff?

Postby speedsixdave » 1 Jan 2021, 7:57pm

tommydog wrote:Good news, I have just found a 5 arm 130 BCD crank at the bottom of my spare parts bin. The 130 BCD crank will give me more options for larger chainrings that are compatible with the Hebie Chainglider. I could therefore go for one of the larger Surly rings in my desired size. But when doing some research, I came across a British company called bikepunx - Has anyone heard of this company, or know if their stuff is any good? They seem pretty reasonably priced and sell 3mm thick stainless steel chainrings. 3mm is bang on spec for the Hebie Chainglider. They list up to 47t in 130 BCD on their website, but when I emailed them they said they could also do a 48t Chainring. This is what I am considering:

https://www.bikepunx.com/5-x-130-bcd-st ... 1822-p.asp

They list if for 1/8" chains. On Rohloff's website they say 1/8" chains are compatible with their cogs, but they go on to say they don't recommend it. But I note that KMC do a dedicated 1/8" cog for Rohloff - so maybe that would be a good option?

https://hollandbikeshop.com/en-gb/bicyc ... ck-639383/


Bikepunx is a good find, Tommydog. Just for the sake of the search function this is a link to British-made stainless steel chainrings and sprockets for Rohloff, hub gears and single speed bikes. The prices are not egregious so why not buy and review yourself? If I hadn't just bought Stronglight rings for the tandem I'd eb having one too. Terrible name though - a bit like Brewdog, the product is great but the punk styling is a bit cringeworthy.
Big wheels good, small wheels better.
Two saddles best!

Brucey
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Re: What chainring and rear cog for Rohloff?

Postby Brucey » 1 Jan 2021, 8:39pm

I just measured some chain parts and I found;

KMC 1/8" bushingless chains were mostly 8.6 to 8.7mm pin length
KMC 1/8" stainless bushingless chain about 8.8mm pin length
KMC 1/8" B1, B1S fully bushed chain 8.8 to 8.9mm pin length

KMC master link for 1/8" chain ~9.8mm pin length
Gusset 'slink' half link 1/8" chain, ~9.5mm pin length

so if 9mm is the limit then most KMC 1/8" chains will fit, but not if you use the master link; the chain would need to be joined using a chain tool. Some 1/8" chains definitely exceed 9mm so presumably won't fit at all.

cheers
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