How to Install Chain on 7 Speed Bike | Sizing, Routing & Links

The job needs one chain tool, the chain’s own connecting pin or master link, and a careful eye on how the chain threads through the rear derailleur — get that last part wrong and the bike will run badly no matter how new the chain is.

Gather What You Need

Before starting, have these ready:

• New chain designed for 6/7/8-speed use
• Chain tool (Park Tool CT-5 or CT-3.3, or any compatible model)
• Master link pliers if the chain uses a reusable link
• Clean rag and degreaser

Whether you are replacing a worn chain or installing one on a fresh drivetrain, a compatible option is worth checking before you buy.

How Do You Size a 7-Speed Chain?

Wrap the chain around the largest chainring and the largest cassette cog without pulling it through the derailleur, then find the point where the two ends meet.

SRAM’s chain service guide confirms this wrap method for MTB 7-speed and other multi-speed setups. Install the chain on the big ring and the biggest cog, pull the ends together, and add the connector plus enough inner links so it just overlaps. Most chains need the two ends to meet with one full link of overlap before adding the pin or master link. When in doubt, size it longer rather than shorter — a too-short chain can damage the derailleur under load.

Route the Chain Through the Derailleur Correctly

Thread the chain from the bottom of the chainring back to the rear cassette, then through the rear derailleur’s pulleys. The chain must pass between the two pulley wheels with the upper run entering the guide pulley first.

SRAM’s service guide shows the routing clearly: shift to the smallest cassette cog first, then route the chain through the rear derailleur pulleys. SRAM’s installation steps put the chain on the smallest cog and thread it through with the cage below or above the tab depending on whether the cage lock is used. On the road, the common mistake is letting the chain wrap around the wrong side of the derailleur tab inside the cage — that creates a rubbing noise and poor shifting. Look for a small metal tab between the pulleys; the chain’s outer plate must sit on the outside of that tab on most Shimano and SRAM derailleurs.

Master link pliers help seat the link fully.

Joining the Chain Ends

Hold both ends together so the pins face outward and the inner plates align. If the chain uses a connecting pin (Shimano style), push it through the outer plate, inner plate, and into the opposite outer plate.

Park Tool’s instructions say to join the ends of the chain using the appropriate connecting rivet, then press the rivet in and break off the pilot tip when the chain uses one. The replacement pin must sit flush with the outer plate on both sides.

Master Link Installation

Slip the two link halves onto the facing pins, then pull the chain taut.

Pin Depth and Tight-Link Checks

After the new pin seats, spin the cranks slowly backward and watch the chain pass through the rear derailleur pulleys.

• Every link should flex freely as it bends around the pulleys
• A stiff spot usually means the pin is too deep or the connecting link is not fully seated

Final Check Before Riding

Shift through every rear gear while pedaling under light load. The chain should move quietly up and down the cassette with no clicking or hesitation.

SRAM’s instructions stress checking that PowerLock halves are aligned and properly engaged before riding, then confirming the link moves freely. A partially connected PowerLock can come apart under load and jam the drivetrain mid-ride. Shimano’s chain manual shows different installation paths for connecting pins versus QUICK-LINK connectors, so always follow the chain manufacturer’s instructions.

Take a look at the best 7 speed bike chain options to see which chain and connector style fits your riding first.

If the chain was routed correctly and the connector fully seated, the drivetrain shifts cleanly and the chain tracks straight through the derailleur cage.