Condensed Answer: A Shimano chain can offer acceptable performance when installed on a Campagnolo drivetrain as long as it matches the number of speeds that the bike has.
Number 1 Requirement for Chain Compatibility
For 2 chains to be interchangeable, they both have to be designed for the same number of speeds. For example, if chain A is made for a 9-speed drivetrain, the replacement chain should also be 9-speed.
Chains have an inner and outer width. The outer width of the chain is essentially the total width. The inner width is the space between the chain’s inner plates.
As the number of speed increases, the outer and to some extent the inner width of the chain decreases. Or in other words, an 8-speed chain is a lot wider than an 11-speed chain.
Why?
The overall width of a cassette does not change much regardless of the gear number. Consequently, the cogs of cassettes with more gears are positioned closer together. The thickness of the cogs is decreased by a minimal fraction too.
The chain designed for that number of gears has to reflect the new density of the cogs so that it doesn’t rub. For example, if an 8-speed chain is put on an 11-speed drivetrain, its outer plates will come in contact with the cogs surrounding the one in use.
That said, it’s possible to use a chain designed for more speeds than the cassette has. For example, using an 11-speed chain on a 10-speed cassette is not unheard of. This combination works because the chain is even narrower than the original and thus cannot cause rubbing.
Some people even claim that using a narrower than prescribed chain results in faster shifting and a quieter drivetrain.
Chain Widths
8-speed Chains
8-speed chains produced by the major manufacturers (SRAM, Shimano, Campagnolo, KMC…etc.) are about 7.1mm wide (outer width) and are therefore interchangeable.
Since 8-speed chains are narrower than 5,6 and 7-speed chains, they can also be used on 5,6 and 7-speed drivetrains. (Hence why 8-speed chains are often labeled as 6/7/8-speed chains).
9-speed Chains
9-speed chains have a 6.7mm outer width across major brands and are also interchangeable.
10-speed Chains
10-speed chains are between 5.82mm and 6.1mm. The width is close enough for the models to be interchangeable across brands.
11-speed Chains
11-speed chains are about 5.62mm wide and are also cross-compatible.
12-speed Chains
As expected, 12-speed chains are the narrowest at 5.25mm and are also cross-compatible.
Cog Pitch Differences
The term cog pitch refers to the center to center distance between two adjacent cogs on a cassette.
The formula for calculating the cog pitch of a cassette is:
Cog Pitch = Cable Pull x Rear Shift Ratio
(The cable pull is the amount of cable that the indexed shifter pulls or releases; the rear shift ratio reveals how much the derailleur moves per 1mm of cable pulled or released by the shifter.)
Since Campagnolo and Shimano components have slightly different cable pull and rear shift ratios, the cog pitch of the brands’ cassettes differs too.
The table below contains the cog pitches of Shimano and Campagnolo cassettes in millimeters:
| Speed | Campagnolo | Shimano | Difference in % |
| 8 | 4.90 | 4.76 | 2.85% |
| 9 | 4.90 (old), 4.50 (new) | 4.25 | 5.88% |
| 10 | 4.20 | 3.91 | 6.9% |
| 11 | 3.90 | 3.78 | 4.87% |
Conclusion: Campagnolo cassettes have an ever so slightly larger cog pitch than Shimano. Or in other words, the distance between the cogs is larger. Consequently, Shimano chains could end up narrower than needed for ideal shifting. The narrowness may result in somewhat slower shifting, but at least the chain will not cause noticeable rubbing.
The Downsides of Using Chains From Different Brands
- Less Than Ideal Performance
While chains from different brands are usable, only a chain produced by the manufacturer of the drivetrain guarantees optimal performance of the components. Why? Because there are subtle differences between brands. For example, the spacing between the rear cogs and the thickness and shape of the chainrings could vary.
Also, each major producer performs drivetrain tests with in-house chains. Consequently, the manufacturer cannot always guarantee optimal performance when a chain of a different brand is used.
- Component Wear
The chain may wear prematurely due to rubbing or uneven stress.
- Warranty Loss
The use of non-original chains can void the warranty of other parts involved in the drivetrain. However, whether this will happen depends on the specific bike shop that you have purchased the parts/bike from.
