This post will give an overview of bicycle driving chains standard dimensions. Each chain has three important dimensions: pitch, inner width and outer width.
If you have any questions (or additions and corrections), please use the BikeGremlin forum:
www.bikegremlin.net
Table Of Contents (T.O.C.):
- Bicycle driving chain pitch
- Chain inner width
- Chain outer width
3.1. Bicycle chain width standards table - Bicycle “chain construction and standards” video
TL/DR
If you read this, you will know:
- How long is a bicycle chain link (this is called “chain pitch“)?
- How do chain inner widths differ depending on the number of speeds (why do the high-speed narrow chains get stuck on single speed wide chainrings)?
- How do chain outer widths differ (why do low-speed wide chains get stuck between high-speed narrowly spaced cassette sprockets)?
I’ve also added a chain width table.
1. Bicycle driving chain pitch
Chain pitch is the distance at which the pins are placed. It is measured by measuring the distance between 3 links, then dividing it by two.
For detailed explanation of chain pitch, and why measuring three pins gives a more accurate result read the post Chain wear (“stretching”). For this post it suffices to say that bicycle chain pitch is exactly 1/2 inch (12.7 mm). This goes for all the bicycle chains, regardless of the speed number.
2. Chain inner width
Inner chain width is the spacing between a pair of inner plates. It is marked in the picture 2.
For inner chain width there are the following standard dimensions:
- Single speed chains have inner width of 1/8″ (3.175 mm).
- Multi speed chains, from 5 to 8 have inner width of 3/32″ (2.38 mm).
- Multi speed chains from 9 to 12 speeds have inner width of 11/128″ (2.18 mm).
- “Exotic” standard for freight bicycles is 5/32″ (4 mm).
3. Chain outer width
Chains for one and multiple speeds differ from each other by the outer width. The more “speeds” a chain is designed for, the thinner the outer plates and shorter the pins are (and they protrude less) – so the outer chain width is smaller (i.e. chain is narrower). Inner width of all the multi speed chains is almost the same – with only single speed chains having a significantly larger inner width.
Note how rollers of all the multispeed chains are of almost the same width, only single speed chain being significantly wider on the inside.
Pitch is the same for all the chains – they are aligned by length.
As can be seen from the picture 3, the outer width differs mostly. This is important for bikes with multiple sprockets, so the chain doesn’t get stuck (too wide), or drop between the sprockets (too narrow – this latter case is practically never a problem in practice).
See this great post by “Graeme_FK” on the Cycle Chat forum for an in-detail explanation of the “fine print” in terms of Campagnolo vs Shimano vs SRAM vs 1x chain compatibility and size differences.
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3.1. Bicycle chain width standards table
Table 1 gives an overview of chain outer dimensions, by number of speeds.
Number of sprockets (speeds) a chain is designed for | Chain’s outer width in mm |
---|---|
All 6 speed | 7.8 |
All 7 speed | 7.3 |
All 8 speed | 7 ~ 7.3 * |
All 9 speed | 6.5 – 6.7 |
10 speed old Campagnolo standard | 6.2 |
All other 10 speed | 5.84 – 6.1 |
All 11 speed | 5.46 – 5.74 ** |
SRAM 12 speed MTB | 5.25 |
Shimano 12 speed MTB | n/a |
Campagnolo 12 speed | 5.15 |
Campagnolo Ekar 1×13 speed | 4.9 |
Rotor 1×13 | Uses SRAM 12-speed MTB chain standard |
** See the two comments by Klaus here (thanks for the valuable feedback),
until I double check and confirm.
4. Bicycle “chain construction and standards” video
My video explaining bicycle chain construction and dimension standards:
For an overview of which chains can be combined with which sprockets, read this post: Bicycle chains compatibility:
If you have any questions (or additions and corrections), please use the BikeGremlin forum:
www.bikegremlin.net
The existing comments posted under this article (questions and answers) have been moved to this BikeGremlin forum thread:
https://www.bikegremlin.net/threads/bicycle-drive-chain-standard-dimensions-article-comments.122/
relja, i just got around to reading your comments of 04 Apr, today, and found them quite enlightening. i agree there are many practical reasons why a truly rigorous, scientific study of chain durability is a considerable challenge for the individual investigator. even so , you have given us a lot to think about, and i am still thinking about it. i’m even thinking of making a hardcopy, to carry around with me and ponder (i don’t carry the kind of ‘device’ that would readily display this much text).
regarding your motorcycle cam timing chain (yes, you had the right nomenclature, we usually just shorten it to ‘timing chain’), it’s no surprise at all that they outlast the external drive chain by a considerable factor. after all, it’s cosily protected from dirt & moisture, and the copious flow of engine oil both lubes continuously, and carries away worn-off particles of its own, abrasive, metal, we hope to be trapped in the engine oil filter.
the great, now deceased, American authority on all things bicycle, sheldon brown, stated that his ideal bicycle drive chain would be housed in a closed oil bath, protected from the elements, and would therefore need to drive an internally geared hub (not practical with a derailleur).
i’d be very interested to see a summary of your results from your trials of various chain makes & models, regarding the (understandably imprecise) relative durabilities. and maybe an index of cost per kilometer? i’ve often wondered if the amazingly costly stainless Wippermann might actually have a lower cost per distance. ??
and thanks again for all your wisdom. stay healthy
where to find roller diameter or do you know for 9 speed chain??
Hi Aditya,
I haven’t measured that – and don’t know if the info is available elsewhere.
My current schedule is hectic, can’t promise any deadlines, but I could measure it, of course, and publish the info.
Relja
a chain is a chain,i dont think any expensive chains are worth the extra money the reason being its still going to wear at the same rate as a cheaper chain,you just go buy the cheapest chain that fits your bike,and you buy a chain that is easy to find quick links for,for me i have never had a problem using even the cheapest shimano chains,infact the cheaper chains are much easier to work with
bicycle chains are measured by chain pin width,example a shimano hg 7-8 speed chain is 7.3 mm wide,more speeds you have the thinner the chain becomes,less speeds the wider the chain,when buying chains allways buy the longest chain and shorten it.
May I ask how much do each size of the chains cost on average?
Hi Michael,
I’d have to put in some time and effort to check the current prices, across brands and models in order to calculate.
Roughly, generally, same brand, same model tier, will cost more as the number of speeds increases.
Taking KMC X-series “Silver” chains for example:
– 7/8-speeds: 15 euros
– 9 speeds: 23 euros
– 10 speeds: 27 euros
– 11 speeds: 32 euros
– 12 speeds: 38 euros
The noted X-series silver chains are of decent quality and their price is what I consider to be reasonable for the quality and durability.
In my experience, the situation is similar with other manufacturers.
* The exact prices may vary depending on many different factors – including taxes and local regulations.