E*THIRTEEN HELIX RACE 12-SPEED 13-52T CASSETTE REVIEW

September 17, 2025

As the years have gone on and E-bikes have become more widely accepted, the industry has seen an influx of E-specific products. These dedicated eMTB components are designed to keep up with the demands and strains that the additional power from motors and added weight from batteries has on our components. Some of the biggest advancements in the E-specific space have been in drivetrains, with several of the big players in the drivetrain game launching products designed to boost reliability and longevity. Shimano Linkglide or SRAM’s Transmission are the most widely adopted, each tackling the challenges that eBikes present from different angles.

e*thirteen is a relatively small player in the drivetrain market, but offers a close-ratio version of their Helix Race 12-speed cassette, which is better suited to eBikes and their demands.

Euro wolf Robert recently reviewed the 9-52T variant of e*thirteen’s Helix Race cassette. As these two cassettes share a near identical construction, I’ll do my best in this review to not repeat too much of what has already been covered by Rob and focus more on the differences and benefits of the ratios applied by the e*thirteen engineers on this close-range variant of the Helix race cassette.

ABOUT THE E*THIRTEEN HELIX RACE 12-SPEED 13-52T CASSETTE

Compared with the recently reviewed 9-52 tooth cassette, this narrow-range e*thirteen Helix Race Cassette variant clocks in with a slightly lower overall range. The range is 400%, with the smallest cog having 13 teeth and the largest carrying 52 teeth. This means the steps between the gears are smaller, which in theory should allow smoother shift feel while under load. It will also allow the rider to spend more of their time at their ideal cadence if used properly.

Out of the box, our Helix Race 13-52T cassette weighed in at 465 grams on our scales, in-between the weight of an Shimano XT 12-speed cassette at 469 grams and a SRAM GX cassette coming in at 452 grams. It doesn’t break any records, however with the intended use on an E-MTB, weight is less of a concern and durability is more of a priority.

The e*thirteen Helix Race Cassette has two price points on offer, depending on the finish selected. The harder wearing PVD-coated variant comes in with a retail of £349.95 / $379.95 / €383.15, while the anodized versions retail for £319.95 / $345.95 / €348.85. At the time of writing this review, there are significant reductions on the price across markets. Both options come in at a higher price point for an aftermarket cassette, however they carry some unique features that may well warrant the higher price point.

For the duration of the test, I’ve mounted e*thirteen’s eBike cassette to my much loved and very much abused Gen 3 turbo Levo comp, which is running the reliable stock SRAM GX drivetrain with an added XX1 chain for a bit of durability. However, much like the 9-52 version of this cassette, it’ll also work well with Shimano and TRP drivetrains. It’s important to note it is not SRAM T-Type compatible.

THE DIRT

The e*thirteen cassette mounted up easily, requiring some different steps to your standard XD cassette but nothing difficult. It became apparent within the first few shifts that the closer gear ranges provided on the e*thirteen cassette were notably different feeling from the stock GX cassette. The shifts generally felt shorter, sharper and smoother overall, and with the gearing leaning more towards a higher cadence I’ve found myself in the lower half of the cassette a lot more of the time, keeping the chain in the harder wearing portion of the cassette for longer.

Shifting under load was significantly improved as well, much to my surprise. The cassette did a really good job of helping the chain transition from gear to gear, with the reduced distance to travel between gears easing the jump. So notable was this improvement, that over the test duration my shifting habits on the Levo became a bit less nuanced. I grew to trust that the up shifts won’t be as harsh, even on the steepest of climbs and under full power of the motor. Being able to rattle up and down the gears so smoothly really made some uphill sections that bit more fun being able to grab a gear under power, as soon as you need it and less ahead of time.

Downshifts felt less jumpy and snappier on the e*thirteen Helix Race 13-52T cassette in most scenarios. As the step between gears is smaller, there was a smooth feeling transition between gears whilst pedaling through rougher terrain. The tighter range of gears allowed me to find the gear I really wanted to be in more often. It may sound silly, but with the stock cassette I would often find one gear up was too easy, and one gear down was just slightly too hard. However with e*thirteen’s close-range cassette installed, I found more usable “goldilocks” gears.

The majority of my rides on my Specialized Turbo Levo are done from the front door of our house and between two of the local hills. Both of these include a stint of road riding before making it to the woodland trail ascents. It’s during these tarmac sections and on flatter fire roads where I noticed the lower overall gear range kicking in, and at times felt as if I was running out of gears. However as this is on an E-bike, it wasn’t a huge issue, as it offered plentiful range within the speed limit of the motor. If you were running this cassette on a regular bike, it might be a factor to keep in mind.

How has the cassette held up? Over the test duration of the cassette, I clocked around 2000km of fairly carefree riding. In that time I’ve had to replace one chain and one derailleur due to wear and tear on them, and overall I would say the cassette has fared reasonably well against the miles. The steel portion of the cassette is impressively fresh, while the aluminum portion has worn at a considerably faster rate, with the largest cog now close to dropping chains. This is not a great surprise, and thankfully the aluminum cluster can be purchased independently of the entire cluster at a reduced cost.

The Wolf’s Last Word

The e*thirteen Helix Race 13T-52T cassette offers a fantastic and unique upgrade for eMTB riders looking for a shorter, sharper and smoother overall gear shifting experience. The range of gears on offer are more useful when combined with the added power of a motor.

All of this does come at a cost, with the price landing closer to high end, lighter weight cassettes. If you were considering this for your eMTB I would recommend forking out the extra money for the PVD coated version of the cassette to maximize your mileage from it!

Price: £319.95 / $345.95 / €348.85 – of £349.95 / $379.95 / €383.15
Weight: 467 grams
Website: ethirteen.com

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