A A A A
What is the difference between 1/8 and 3/32?
 
LinkBack Thread Tools Search this Thread
Old 17th June 2009   #1
boredomdonor
 
boredom's Avatar
What is the difference between 1/8 and 3/32?

What is the difference between 1/8 and 3/32 chains and cogs? Will a 1/8 chain fit on a 3/32 cog and vice versa?

And yes I did search
  quote   reply
Old 17th June 2009   #2
dangerussdonor
 
dangeruss's Avatar
Chain

Modern bicycles use roller chain to connect the cranks to the rear wheel. Chain drives are among the most efficient means of power transmission known. Chain size is specified by pitch and width. The pitch is the distance between rollers (1/2" on all modern bicycle chain). The width is the internal width where the sprocket teeth fit in. Bicycle chain comes in two basic widths:

  • 1/8" chain is used on most single-speed bicycles, and bicycles with internal gearing.
  • 3/32" chain is used on derailer equipped bicycles that have more than 3 speeds.
Chains for derailer applications also come in various external widths. Newer clusters which have more sprockets use chain with thinner side plates and flush rivets.


You will come to learn that Sheldon Brown was your friend http://www.sheldonbrown.com/
  quote   reply
Old 17th June 2009   #3
boredomdonor
 
boredom's Avatar
Wow that was fast! Thanks! But if i was to convert an old racing bike and use the front chainring would it be 3/32 then? And if I was to change it which is better?
  quote   reply
Old 17th June 2009   #4
Dylan
 
Dylan's Avatar
3/32 is narrower that 1/8

therefore

a 3/32 chain wont fit on a 1/8 cog or chainring

but you can get away with using a 1/8 chain on a 3/32 chainring, but not really on a 3/32 rear cog, or at least, i wouldn't do it.
  quote   reply
Old 17th June 2009   #5
Donut!
 
Donut!'s Avatar
Really . . .no UTFS!
  quote   reply
Old 17th June 2009   #6
stompy
 
stompy's Avatar
1/32

I'm surprised I had to say this.
  quote   reply
Old 17th June 2009   #7
boredomdonor
 
boredom's Avatar
Quote:
Originally Posted by stompy View Post
1/32

I'm surprised I had to say this.
Whats 1/32?
  quote   reply
Old 17th June 2009   #8
flickwg
 
flickwg's Avatar
Quote:
Originally Posted by stompy View Post
1/32

I'm surprised I had to say this.
+1
  quote   reply
Old 17th June 2009   #9
MrSmyth
Quote:
Originally Posted by boredom View Post
Whats 1/32?
2/64ths
  quote   reply
Old 17th June 2009   #10
hippy
 
hippy's Avatar
Quote:
Originally Posted by boredom View Post
And yes I did search
For what? "Custard"?
  quote   reply
Old 17th June 2009   #11
Aleksi
 
Aleksi's Avatar
1 divided by 8 = 0.125

3 divided by 32 = 0.09375

(its in inches btw) work it out....
  quote   reply
Old 17th June 2009   #12
RPM
another one of pistonator's piss take threads..
  quote   reply
Old 17th June 2009   #13
Pifko
 
Pifko's Avatar
No one else use 3/8" then?
  quote   reply
Old 17th June 2009   #14
boredomdonor
 
boredom's Avatar
Quote:
Originally Posted by RPM View Post
another one of pistonator's piss take threads..
No its not. Im from Dublin, Ireland and i have an otp Giant Bowery 2009.

Is either one better or worse to use or is it personal preference?
  quote   reply
Old 17th June 2009   #15
Aleksi
 
Aleksi's Avatar
Quote:
Originally Posted by Pifko View Post
No one else use 3/8" then?
no I find 8/3 (flemish ell's) works a little better in the winter
  quote   reply
Old 17th June 2009   #16
Aleksi
 
Aleksi's Avatar
Quote:
Originally Posted by boredom View Post
No its not. Im from Dublin, Ireland and i have an otp Giant Bowery 2009.

Is either one better or worse to use or is it personal preference?
track cogs, chain rings and chains tend to be 1/8

utfs or check out sheldon brown.
  quote   reply
Old 17th June 2009   #17
Aleksi
 
Aleksi's Avatar
1/400 Sumerian cubit chains are pretty good too.
  quote   reply
Old 17th June 2009   #18
Aleksi
 
Aleksi's Avatar
calling plagarist and other attendees of the maths ride.....
  quote   reply
Old 17th June 2009   #19
hippy
 
hippy's Avatar
Quote:
Originally Posted by Aleksi View Post
1/400 Sumerian cubit chains are pretty good too.
These are great. Do you know if you can get them in lilac?
  quote   reply
Old 17th June 2009   #20
tom.
Quote:
Originally Posted by hippy View Post
These are great. Do you know if you can get them in lilac?
Are they NJS or would they require negative shimming?
  quote   reply
Old 17th June 2009   #21
Seeds
 
Seeds's Avatar
Quote:
Originally Posted by boredom View Post
Whats 1/32?
(4 - 3) / 32

You did ask.
  quote   reply
Old 17th June 2009   #22
Aleksi
 
Aleksi's Avatar
Quote:
Originally Posted by hippy View Post
These are great. Do you know if you can get them in lilac?
as far as im aware only gold is currently available in blb

Quote:
Originally Posted by tom. View Post
Are they NJS or would they require negative shimming?
also no and no as It actually derives from an Egyptian measurement.
  quote   reply
Old 18th June 2009   #23
Smallfurrydonor
 
Smallfurry's Avatar
1/8" = Less wear, as components are wider.
More high end kit available

3/32 = Lighter
More forgiving of bad chainline (sideways flex)

Both should be the same in terms of strengh, as its the gap between the side plates of the chain that are thicker on 1/8" not the side plates themselves.
  quote   reply
Old 24th June 2009   #24
simonw7
 
simonw7's Avatar
from my recent experience in a conversion, I made the decision to go with 3/32" transmission (and I really don't remember why) - but i subsequently found that this was quite limiting in terms of availability of sprockets and even more so in chainrings where i was already limited by having to find something with right teeth and right bcd for my cranks

next time it will be 1/8" for me
  quote   reply
Old 24th June 2009   #25
eddie
 
eddie's Avatar
make sure you buy one in white, it iz makes you go faster and stop quicker.
white 1/8" RRP 1.99
  quote   reply
Old 28th December 2012   #26
longdistances
Why do I get the feeling I am going to regret reviving this thread?

New bike comes with 1/8 chainring, 1/8 chain and 1/8 fixed cog, and looking to put a White Industries Dos Eno double freewheel on other side (I don't ride fixed, and having a bit of flexibility in gearing suits what I want the bike to do)

Trouble is the Dos Eno freewheel is 3/32 - with switching between the two cogs chainline may never be perfect, and biggest fear is whether this will be enough to affect drive, or end up derailing chain

1/32 is a tiny difference in chain width, but is it going to screw up my plan for a simple ratio change? next best option is a custom free/free hub (Phil Woods or similar) but the tyres I plan to run are directional so not really an option

Any suggestions
  quote   reply
Old 29th December 2012   #27
snottyotterdonor
 
snottyotter's Avatar
It'll be fine.
  quote   reply
Old 29th December 2012   #28
longdistances
Definitive answer took me by surprise there!

Looks like I need to start shopping for parts :)
  quote   reply
Old 29th December 2012   #29
snottyotterdonor
 
snottyotter's Avatar
It'll never work.
  quote   reply
Old 29th December 2012   #30
Tennersdonor
 
Tenners's Avatar
It might be fine, but there's a possibility of fatal failure.
  quote   reply
Old 29th December 2012   #31
adroitdonor
 
adroit's Avatar
Quote:
Originally Posted by snottyotter View Post
It'll be fine.
lol
  quote   reply
Old 29th December 2012   #32
mechanical_vandal
 
mechanical_vandal's Avatar
Quote:
Originally Posted by longdistances View Post
Why do I get the feeling I am going to regret reviving this thread?

New bike comes with 1/8 chainring, 1/8 chain and 1/8 fixed cog, and looking to put a White Industries Dos Eno double freewheel on other side (I don't ride fixed, and having a bit of flexibility in gearing suits what I want the bike to do)

Trouble is the Dos Eno freewheel is 3/32 - with switching between the two cogs chainline may never be perfect, and biggest fear is whether this will be enough to affect drive, or end up derailing chain

1/32 is a tiny difference in chain width, but is it going to screw up my plan for a simple ratio change? next best option is a custom free/free hub (Phil Woods or similar) but the tyres I plan to run are directional so not really an option

Any suggestions
A 1/8" chain is designed to work with a straight chainline.

A 3/32" chain is designed to work with derailleur gears which means an often staggered chainline. It will flex more easily than a 1/8" chain to allow this.

Given that the chainline will always be slightly off with the Dos you can see why they went for 3/32".

A 1/8" chain will happily sit over a 3/32" cog and will have some side to side play - possibly enough to allow for the difference in chainline but depending on how close together the cogs are a 1/8" chain may foul the larger cog when used on the smaller one. (Try putting a 1/8" chain onto a 9 or 10 speed cassette to see what I mean).

So, it'll probably work with an 1/8" chain, would almost certainly work better with a 3/32" chain but will never work as well as a single cog/perfectly straight chainline regardless of what chain you use anyway.
  quote   reply
Old 29th December 2012   #33
Oliver Schickdonor
 
Oliver Schick's Avatar
3/32 is 3/32. 1/8 is 4/32.
  quote   reply
Old 29th December 2012   #34
Oliver Schickdonor
 
Oliver Schick's Avatar
Those were the days when important topics were being discussed on the forum.
  quote   reply
Old 29th December 2012   #35
colm
Dont think Ive ever seen a definitive reason to choose 1 over the other besides 1/8" having more surface contact area between chain and cogs so less deformation on the chainring teeth as the force is spread out more.
The Japanese keirin riders only ever use 1/8" but there are 3/32" dura ace chainrings available and Id have to double check but they may have njs stamps on them.

both chain types have the same side plate thickness so share same tensile strength, not sure how much lighter 3/32" is,
ill weigh equal lenghts of new kmc 510hx and 610hx some time for comparisson. The lighter weight would prob offer negligble acceleration advantage, the chainrings are same thickness up until the support ridges at the edges were the teeth begin.

Shimano had their Dura Ace 10cm pitch but overall it wasnt much of a weight saving.

in conclusion 3/32" looks funny on a fixed/track bike, it looks weak and skinny. 1/8" should always be used with the largest chainring possible
  quote   reply
Old 29th December 2012   #36
1000archangels
 
1000archangels's Avatar
3/32 have never been approved by njs
  quote   reply
Old 30th December 2012   #37
mechanical_vandal
 
mechanical_vandal's Avatar
Quote:
Originally Posted by 1000archangels View Post
3/32 have never been approved by njs
Absolutely this.

I've heard it said that at least at the lower end of the price scale, 3/32" chain is more actually stronger and more reliable than 1/8". This would supposedly be due to singlespeed drivetrains being somewhat outdated and thus, chain manufacturers would be investing time, effort, research etc into multispeed chains.

Pretty sure this would be invalid by the time you got to talking about NJS stamped chains.

My experience, never had a totally 1/8" drivetrain skip or jump or miss a beat but when I fitted a 3/32" cog to my otherwise 1/8" track bike's drivetrain (should be compatible) it ran like shit, catching and clicking and banging under load.

I've also had a fully 3/32" singlespeed setup drop a chain which almost put me under a transit van.
  quote   reply
Old 23rd January 2013   #38
EdwardZ
Quote:
Originally Posted by mechanical_vandal View Post
I've heard it said that at least at the lower end of the price scale, 3/32" chain is more actually stronger and more reliable than 1/8".
The conjecture held perhaps in the 1970s but no longer. 3/32" is now obsolete. The old Sedis and Regina chains that used to be so popular are no longer available--- production ended decades ago. For the past 2 decades almost all road chains are bushingless designs and all the latest and greatest are for multigear setups of 8 and beyond. By current standards the Rohloff SLT-99 (no longer in production), in its day with 7.1mm (6.8mm for the 9-speed version) the narrowest and most flexible chain on the market, is wide (Campa's 11-speed chain is 5.5mm wide).

For 3/32" track/singlespeed you want a chain with bushings and 7.8mm wide. These are now at the fringe. HIghest end chains seem to be either old school 1/8" for elite track (Izumi and friends) or super narrow chains designed for fast gear changing in multi-gear systems. In the middle are 1/8" BMX chains. With BMX still going strong, singlespeed/fix-gear become cult and road cycling drifting off into sub 6mm spheres.. the pendulum has swung back strongly for 1/8".

I think the only argument for 3/32" left is the available of old Campa NR/SR 144 chainrings. While Campa made them with 42 to 70 teeth most of the NOS chainrings one will find are limited to a few popular sizes.
  quote   reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
It's the little things that make the big difference Velocio Bikes & Bits 15 16th May 2010 21:45
What's the difference between a Nitto B258AA and B259AA? wools Bikes & Bits 11 25th April 2009 12:00
Noticable difference between these two wheelsets? aserota Bikes & Bits 8 5th March 2009 01:09
Nitto jaguar - drop difference dogmatic Bikes & Bits 14 14th December 2008 13:39
What's the difference Vinz Bikes & Bits 7 1st February 2008 10:27

All times are GMT. The time now is 22:19.
Creative Commons License, BY-SA v2.0
no new posts