Sram Vs Shimano Drivetrains Differences

Electronic Drivetrains

Shimano was the first company to introduce an electric drivetrain - the DI2 system was launched in 2009 and used exclusively on road bikes. This electric drivetrain is now offered across the full range of bikes; it’s still a wired system and uses a rechargeable battery.

SRAM released their eTap Red system in 2015 for road bikes, and the AXS system was introduced in 2019 for mountain bikes. The AXS system is wireless, making it easy to set up - but this means the AXS requires two batteries, and these batteries have a relatively short period of use, around 20 hours - so they do require some checking to ensure they are charged enough for each ride.

Freehubs

Although Freehubs are not precisely in a groupset - they still play an essential role in finding what groupset can be used on a bike. Shimano created what they called the Hyperglide back in the 1990s. This became a standard freehub and will work with between every 8-10 speed Cassette from either Shimano or SRAM.

As rear cassettes have grown in size, freehubs have reduced in size. To use a GX Eagle drivetrain from SRAM you would need SRAM’s own XD freehub body. Shimano also had to create a smaller freehub - the Micro Spline - suitable for both 11 and 12-speed cassettes.

Shifters

SRAM and Shimano shifters can both downshift gears in single strokes. The Shimano Rapid Fire trigger shifter has a two-way release, which allows the upshift lever to move in both directions. This allows the rider to change gears using their thumb or index finger.

Crank Arms

The biggest difference between the Crank Arms from both Shimano and SRAM is that Shimano does not use carbon fibre on their crank arms. Shimano's technology is known as Hollowtech, which works well and provides a durable and lightweight crank arm that uses hollow aluminium. SRAM uses carbon fibre, which is lighter and more robust - but less durable.

1 x Drivetrains

Both manufacturers use 1 x drivetrains across the entire range, with SRAM introducing the XX1 Groupset and making 1 x drivetrains mainstream again. Shimano stuck with 2 x drivetrains for a while but then adopted 1 x drivetrains. The biggest solution to gear reduction with a 1 x drivetrain came from SRAM in 2016 with the Eagle 1X drivetrain.