# 1/8 chain on 3/32 sprocket: good, ok or bad?



## onkel (Jan 25, 2009)

What do you think of this combination: 1/8 chain on 3/32 sprocket and chainwheel?

I bought chain (gold, see pic) and sprocket from the same (web)shop and they knew it was going to be for use together. My bike mech asked why I wanted to use such a wide chain with my narrow sprocket...  
I bought the silver chain (see other pic) from him instead. Seems like a more logical combo to me. Should I try to get the webshop to take the gold chain back. It was expensive, over £30.

What do you guys think?

And can anyone please tell me how to get the pictures IN the post, instead of under it. I've searched the forum but not found any clues.

Thanks
onkel


----------



## Harryburgundy (Nov 28, 2007)

No problem at all...I do the same. If you havn't a tensioner or derailleur to foul with the wider 1/8th...it works.


----------



## 7daysaweek (May 7, 2008)

it depends (heavily) on the cog. I ran a 1/8" kmc z410 on a 3/32 surly cog for about 6 months without dropping the chain once... same chain would not stay on a boone cog for more than about a mile. It was really irritating. Switched to a 3/32 chain and after multiple adjustments, finally got it right.

Just ride it the way you've got it and if no problems then you're set. Good luck.


----------



## onkel (Jan 25, 2009)

Ok, thanks guys. :thumbsup: 

I interpret this as "It may work, even if it's not optimal - but you never know until you try it."

So... I'll try and return the chain. If they won't accept that, no biggie, I'll keep it for a future project or give it to some poor bmx kid who wants a blingy bike.

onkel


----------



## Schmucker (Aug 23, 2007)

I've done it a lot on multiple bikes with multiple setups and have never ever had a problem.


----------



## wookalar (Jan 30, 2004)

For those of you who have done this, does the same go for the front chain ring (I'm assuming they make 1/8-in chain rings)? 

I'm thinking of putting together a SS commuter mostly from spare parts I have taking up space in the garage and I know the only front chain rings I have are from geared bikes which I would think would be 3/32.

If I were to buy front ring, cog and chain would I be better off with 1/8-in all around?


----------



## diylighter (Sep 4, 2008)

wookalar said:


> For those of you who have done this, does the same go for the front chain ring (I'm assuming they make 1/8-in chain rings)?
> 
> I'm thinking of putting together a SS commuter mostly from spare parts I have taking up space in the garage and I know the only front chain rings I have are from geared bikes which I would think would be 3/32.
> 
> If I were to buy front ring, cog and chain would I be better off with 1/8-in all around?


BUMP. Please, I would like to know too if this is ideal. I have read some stuff saying go all 3/32 (including 8 spd chain), and there seem to be a lot more parts available.

Thanks!


----------



## mack_turtle (Jan 6, 2009)

no reason whatsoever to use a 1/8" chain unless you plan to pedal grinds handrails on your bike. 1/8" chains are strong for bmx abuse but most 3/32" chains are better for "normal" use.


----------



## iowamtb (May 17, 2014)

So on my Jamis I got a Race Face narrow wide front running an 8 speed chain with gears in back. I did have my Surly rear cog and a tensioner running this bike as a SS with the same chain. I am building a new bike with the same front ring and going to use the same Surly rear cog. Should I go again with an 8 speed chain or will the 3/32 chain fit the narrow wide chainring?


----------



## mack_turtle (Jan 6, 2009)

an 8 speed chain is a 3/32" chain.

I suppose that size is nominal, but there are single-speed specific "narrow" chains as well, but most "narrow" chains that are referred to as 3/32 inch. an 8-speed chain will be just fine.


----------



## iowamtb (May 17, 2014)

mack_turtle said:


> an 8 speed chain is a 3/32" chain.
> 
> I suppose that size is nominal, but there are single-speed specific "narrow" chains as well, but most "narrow" chains that are referred to as 3/32 inch. an 8-speed chain will be just fine.


Guess I never measured lol


----------



## KgB (Jan 13, 2004)

1/8 inch is better suited for 1/8" cogs, it will work but not ideal, too much side play


----------



## mattbyke (Jan 14, 2015)

Good 1/8 chains for SS are best. I use kmc. Myself and my friends break 8 speed chains. Then again we are not light men


----------



## iowamtb (May 17, 2014)

Never mind lol


----------



## mack_turtle (Jan 6, 2009)

mattbyke said:


> Good 1/8 chains for SS are best. I use kmc. Myself and my friends break 8 speed chains. Then again we are not light men


that statement is controversial.

1. which KMC chain are you using? KMC makes dozens of chains. the only SS-specific chain I would use would be a z610hx, which is a narrow single-speed specific chain. it's basically a narrow version of their popular z510hx 1/8" bmx chain. there is no reason to use a wide chain on narrow chainrings. wider is not stronger. they just slide around on the teeth.

2. modern 10 speed chains are incredibly strong. there is nothing about a wider chain that makes it inherently stronger. if you are breaking 8 speed chains and not SS chains, either you are using crappy chains, or you are doing something wrong.

I can't find it now, but I have read a few charts comparing the tensile strength of various chains. I think it was something from Shimano illustrating the strength of their chains, biased as that might be. might be worth a bit of research.


----------



## iowamtb (May 17, 2014)

the one thing about using an 8, 9, or 10 speed chain on a single speed is that they are designed to be shifted on different cogs. So therefore if you have a chain line that's not absolutely perfect its not going to cause an issue was a single speed specific chain may pop and make all kinds of noise.


----------



## mack_turtle (Jan 6, 2009)

my chainline is never "absolutely perfect" and I do not get noises with my very tight 10-speed chain. it's within 2-3mm of "perfect," close enough that it never causes problems. if you do, it must be user error because there is something else going on. at least it does not rattle and slide around like a fat chain would.


----------



## diylighter (Sep 4, 2008)

iowamtb said:


> the one thing about using an 8, 9, or 10 speed chain on a single speed is that they are designed to be shifted on different cogs. So therefore if you have a chain line that's not absolutely perfect its not going to cause an issue was a single speed specific chain may pop and make all kinds of noise.


I think technically a chain is not designed to be run single or geared, it's the cogs and chainrings that are ramped for shifting.

I ended up getting an 8 spd for my motobecane 29+ SS, because I needed to change rear cogs and the local shop only had 3/32. Since the chainring was already 3/32, I didn't need to change that. So for $13 for a chain and $7 for a cog I was good to go. No issues in the snow with it yesterday. Quiet as a mouse, and hammered on it.


----------



## iowamtb (May 17, 2014)

mack_turtle said:


> my chainline is never "absolutely perfect" and I do not get noises with my very tight 10-speed chain. it's within 2-3mm of "perfect," close enough that it never causes problems. if you do, it must be user error because there is something else going on. at least it does not rattle and slide around like a fat chain would.


I get no noise. I am saying a fella told me once that a ss specific chain can bind if chainline is not perfect Whereas a regular chain has more flexibility to compensate. I have never run a ss specific chain so I cannot tell you from experience.


----------



## J.B. Weld (Aug 13, 2012)

diylighter said:


> I think technically a chain is not designed to be run single or geared, it's the cogs and chainrings that are ramped for shifting.


Actually chains are designed differently, 1/8 ss specific chains have flat side plates and 3/32 chains for geared bikes have side plates that are shaped to efficiently catch the cogs and chainrings while shifting gears.

I think 3/32 chains are best for 3/32 rings.


----------



## diylighter (Sep 4, 2008)

J.B. Weld said:


> Actually chains are designed differently, 1/8 ss specific chains have flat side plates and 3/32 chains for geared bikes have side plates that are shaped to efficiently catch the cogs and chainrings while shifting gears.
> 
> I think 3/32 chains are best for 3/32 rings.


Interesting. I noticed some similarities with motorcycle chains. I guess this is one of them.


----------

