E-MTB chain guides

How to choose an electric mountain bike chain guide

The motor’s torque and the bike’s weight can throw the chain off where a non-electric mountain bike would have kept it in place. On an electric mountain bike, the chain guide mounts to the motor unit rather than the frame: check compatibility with the motor, not the bike brand.

The mount attaches to the motor

• Shimano EP8 and E8000 : dedicated CD-EM800, SM-CDE70 and SM-CDE80 mounting plates.
• Bosch Performance CX Gen 4 : E.Thirteen E-Spec+ and equivalents.
• A guide designed for one motor will not fit another, even from the same manufacturer and even if it looks like it should.

With or without a bash plate

• With a bash plate : the guide also protects the chainring from rocks and tree stumps. The choice for enduro and all-mountain riding.
• Without a bash plate : lighter and less conspicuous, and sufficient for cross-country riding and touring, where the chainring rarely strikes obstacles.
• Shimano offers the CD-EM800 in a version 55 mm : the measurement refers to the chainring’s chainline, not the width of the guide.

A chain guide does not replace a narrow-wide chainring

A narrow-wide chainring already holds the chain well in normal conditions. The guide steps in when an impact briefly slackens the chain — something that happens much more often on a heavy, fast bike with long-travel suspension. The two work together.

To find out more: How to upgrade your electric mountain bike

See also: Electric mountain bike chainrings · Mountain bike chain guides and bash guards · Electric mountain bike crank arms