Upgrade or replace your compatible mountain bike drivetrain with this Shimano M315 shifter and Shimano Altus RD-M310 rear derailleur combination.

Designed for compatible 7-speed and 8-speed MTB drivetrain setups, this combination is a practical choice for bicycle repairs, drivetrain replacements and home workshop projects.

The Shimano SL-M315 Rapidfire Plus shifter is designed for 2/3×8/7-speed applications, giving you a choice of 7 or 8 rear gears depending on the drivetrain configuration. Shimano's technical documentation confirms the SL-M315 range as 2/3×8/7-speed.

The Shimano ALTUS RD-M310 rear derailleur is an 8/7-speed model. Shimano documentation identifies the RD-M310 as an 8/7-speed rear derailleur and provides compatibility information for suitable MTB drivetrain configurations.

Ideal for 21-Speed or 24-Speed MTB Setups

When matched with a compatible triple front chainset, the system can be used in common 21-speed (3×7) or 24-speed (3×8) mountain bike configurations.

This makes the set suitable for riders looking to replace worn or damaged shifting components without changing the entire drivetrain.

Key Benefits

Please Check Compatibility Before Ordering

Compatibility depends on the complete drivetrain, including the cassette/freewheel, chain, front chainset, shifter configuration and cable routing.

The RD-M310 is specified by Shimano for 7/8-speed use, while the M315 shifter is specified for 2/3×8/7-speed systems.

Please compare your existing component model numbers and drivetrain configuration before purchasing.

If you are unsure, check the specifications of your current bicycle or ask a qualified bicycle mechanic before installation.

A Practical Shimano MTB Replacement Set

For riders repairing an older or compatible mountain bike, this Shimano M315 and ALTUS RD-M310 combination offers a straightforward way to replace key rear shifting components.

Order today and refresh the shifting system on your compatible MTB.

What is the Shimano M315 and RD-M310 set?

The Shimano M315 and RD-M310 set combines a Shimano M315 7/8-speed MTB Rapidfire Plus shifter with an ALTUS RD-M310 7/8-speed rear derailleur for compatible mountain bike drivetrains. It can be used in suitable 21-speed or 24-speed configurations.

Is Shimano M315 compatible with 7-speed?

Yes. Shimano specifies the SL-M315 shifter for 2/3×8/7-speed applications.

Is the RD-M310 7 or 8 speed?

The Shimano ALTUS RD-M310 is specified as an 8/7-speed rear derailleur.

Can this set be used on a 21-speed bike?

Yes, where the bicycle uses a compatible 3×7 drivetrain and the other drivetrain components are correctly matched.

Can this set be used on a 24-speed bike?

Yes, where the bicycle uses a compatible 3×8 drivetrain and the cassette/freewheel, chain and front drivetrain are compatible.

FAQ — FAQ Schema Friendly

Is the Shimano M315 shifter 7 or 8 speed?

The Shimano M315 shifter is designed for compatible 7-speed and 8-speed rear drivetrains. Shimano specifies the SL-M315 as a 2/3×8/7-speed Rapidfire Plus lever.

Is the Shimano RD-M310 7 or 8 speed?

The RD-M310 is a Shimano ALTUS 7/8-speed rear derailleur.

Will this fit a 21-speed mountain bike?

It can fit a compatible 3×7 21-speed MTB drivetrain, provided the cassette/freewheel, chain, front drivetrain and cable setup are compatible.

Will this fit a 24-speed mountain bike?

It can fit a compatible 3×8 24-speed MTB drivetrain, subject to correct drivetrain compatibility.

Does the RD-M310 work with 8-speed?

Yes. Shimano identifies the RD-M310 as an 8/7-speed rear derailleur.

Is the Shimano M315 a Rapidfire shifter?

Yes. The SL-M315 is a Shimano Rapidfire Plus shifting lever.

What type of bike is this designed for?

It is intended for compatible mountain bike/MTB drivetrain applications.

Does the set include a cassette?

No. This listing is for the M315 shifter and RD-M310 rear derailleur only, unless your specific package description states otherwise.

Does it include a chain?

No. A chain is not included unless specifically stated in your listing.

Does it include a gear cable?

Only state that a gear cable is included if it is physically supplied with your particular item.

Can I install it myself?

An experienced home mechanic may be able to install it, but correct cable routing, limit-screw adjustment, indexing and drivetrain compatibility are important. Shimano recommends following its service instructions and checking adjustment carefully.

Is it compatible with every Shimano 7/8-speed drivetrain?

Not necessarily. Shimano speed compatibility alone does not guarantee compatibility with every drivetrain. Check the complete system before ordering.

Model numbers matter.

This listing clearly identifies the shifter as M315/SL-M315 and the rear derailleur as RD-M310, making it easier for buyers to compare the components with their existing bicycle.

For technical verification, refer to Shimano's official technical documents and service instructions before installation. Shimano maintains an official library of manuals and technical documentation for its components.