5-Star from Thrash Test
Updated : 2009-08-06

KMC X9SL Gold Chain

5-star Ratings

Connecting your leg strength to forward momentum

(from the Thrash Test Special, [Mountain Bike Action] September 2009)

KMC is all about focus. They make chains and that’s it. They produce their chains in 11 factories and manufacture private-label chains for some big-name component companies.

Tech features: The X9SL Gold chain is nine-speed compatible, has a titanium-nitride coating, uses a hollow pin and plate in every link, and features KMC’s signature Double X Bridge structural design. The outer and inner plate of every link is chamfered to improve shifting performance, and the chain uses bushingless construction. KMC’s MissingLink connects the chain without tools. Our properly sized chain weighed 8.8 ounces (half an ounce less than the claimed weight).

After the thrashing: While no tools are required to install the chain’s MissingLink, you will need a chain tool to reduce the X9SL Gold chain to the proper number of links for your application. Our chain with the MissingLink installed took close to an ounce of moving drivetrain weight off the Shimano chain it was replacing. The MissingLink was easy to install, and their instructions strongly recommend that you always use a new one (included with the chain), when installing a new chain.

This sounds silly, but the chain’s color makes the bike look faster just sitting there, and it makes you feel faster when pedaling. Once up to speed, the chain is a quiet, smooth operator that doesn’t even complain when you intentionally cross-chain (running the chain on the large chainring and large cassette cog or on the small chainring and smallest cassette cog). The chain moves from cog to cog and chainring to chainring smoothly. It does what a chain is supposed to do—let you forget about it and ride.

While the KMC X9SL Gold chain has only been on our test sled for a month (a very short time compared to the chain’s lifespan), checking in with project bike builders on both the East and West coasts revealed that this is the chain of choice for not only reducing weight, but delivering superior performance. We don’t give out many five-star ratings anymore, but this one deserves it. Highly recommended by the MBA wrecking crew.