Bike Perfect Verdict
The e*thirteen Helix Race 9-52t cassette offers slick shifting performance, a huge 578 percent gear range, and low weight that will appeal to MTBers and adventurous loaded bikepackers alike. There’s no doubt it offers a tangible upgrade over stock cassettes, but it’s marginal gains compared to e*thirteen's more affordable Helix Plus .
Pros
- +
Unbeatable gear range
- +
Fast and precise shifting
- +
Compatible with SRAM, Shimano, and TRP 12sp
- +
Lightweight
- +
Plenty of colors
Cons
- -
Tight fitment on my review sample
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XD driver only
- -
Expensive
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Big jump between 11t and 9t sprocket
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Not SRAM T-Type compatible
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SRAM released Eagle back in 2016 – the 10-50t cassette that would be the first wide-range cassette and the final nail for off-road front derailleurs. Shimano followed suit, literally one-upping SRAM with a 10-51t before SRAM reinstated itself as the range masters in 2020 with the release of its 10-52t cassette, which has a generous 520 percent range.
There is always room to eke out a little more performance, leaving an open door for brands like e*thirteen to manufacture cassettes that add even more range to your MTB groupset. I previously tested the e*thirteen Helix Plus cassette which offers a wide 556 percent range using a 9-50t cluster. More is definitely more, and e*thirteen has taken it even further with the e*thirteen Helix Race, which has a massive 578 percent range. Can you have too much of a good thing though?
Design and build
To give the Helix Race cassette its extra 22 percent of range over the Helix Plus, e*thirteen has upped the largest cog size to a 52t. The cassette uses a two-piece forged and CNC-optimized design, with the two largest cogs using AL-7075-T651 alloy and the rest of the block using SCM445 Steel. The steel section has the same 9, 11, 13, 15, 17, 20, 23, 27, 31, 36t range as the Helix Plus, with the alloy 43t and 52t giving the extra range.
The larger spread of gears doesn’t come at the expense of weight either. Despite the larger 43, 52t sprocket size of the Helix Race cassette, e*thirteen has managed to shed 8g off with the Helix Race weighing in at 407g on my scales. That means it’s also a good bit lighter than Shimano’s XT 10-51t cassette (469g claimed) and SRAM’s 10-52t cassette (450g claimed).
The cassette is only compatible with SRAM XD/XDR freehubs, the alloy cluster slides onto the XD splines and is tightened using the 3mm pinch bolt to 3nm torque. If you are fitting the cassette to an XDR driver, you will need to use a supplied spacer behind the cassette. The steel cluster then seats into the alloy carrier using a chain whip or HG lockring tool to lock the two sections together. The tolerances on the interlocking tabs of my test sample were very tight and it took a few goes and a fair bit of force to get the steel cluster fully engaged into the locked position. Once locked in there is a small grub screw to make sure everything stays in place. Other than the difficulty of locking the two sections together, fitment was a straightforward process.
If you already have a Helix Plus cassette you can retrofit the Helix Race 43, 52 alloy cluster to your current setup, rather than buy a whole new cassette. The Helix Race can be color-matched to your other e*thirteen products, the alloy cluster comes in five different colors; Grey, Bronze, Naranja, Eggplant, or the PVD (Physical Vapour Deposition) Intergalactic finish which I have on test and is said to be harder wearing.
It’s worth noting that while the Helix cassettes are compatible with 12-speed drivetrains from Shimano, SRAM, and TRP, e*thirteen’s cassettes aren’t compatible with SRAM’s T-Type Transmissions as the cog spacing and overall size of the T-Type cassette is different.
Performance
Out on the trail, the combination of SRAM GX AXS derailleur and Helix Race cassette gives sharp and precise gear changes across all the cogs. It’s been fit and forget requiring no readjustment or fettling and consistently changing no matter the levels of slop on the block or badly timed shifts I have subjected it to. Those seeking ultimate efficiency will be quick to point out that smaller sprockets are less efficient although the usually low cadence pedaling when cruising at high speed produced no discernable drag.
A wider gear range means bigger jumps are needed to get between the 9t and 52t cogs yet the extra jumps between tooth counts are barely noticeable across the block. The only discernible leap is the 11t to 9t, but unlike lower gears where large jumps between gears can disrupt cadence, gaps between harder gears are less of an issue and it rarely bothered me.
It’s not just a range and smooth shifting upgrade either, it could make your suspension work better too. Although you are unlikely to notice the difference when riding, your suspension might. Lowering the unsprung mass (the weight of the components that aren’t suspended by the suspension) will reduce the amount of work your damper needs to do to absorb bumps. Less work to move your wheels around will mean better suspension performance. A 50g difference in unsprung mass between the Helix Race and a GX cassette will probably be very subtle, however, if you’re upgrading from a cheap cassette the difference could be over 200g and be quite pronounced on rough trails.
Verdict
The e*thirteen Helix Race will be a significant upgrade for your drivetrain if you’re looking for the ultimate gear range to tackle steep climbs, loaded bikepacking, or just prefer to spin up climbs. Not everyone will need so much range though, for most of the MTB riding I do I am more than happy with a 10-50t cassette. I’m generally not climbing anything that demands a 52t to get up and I’m certainly not descending anything that requires a 9t. I don’t hate having the option though, and the range in the middle of the block is still close enough for me to comfortably pedal around without feeling stuck between gears that are too easy or too hard. Luckily, the Helix Race offers more than just a wide gear range, shifting is slick and precise plus weight saving is always welcome on long climbs and potential suspension flattery.
It’s not a cheap upgrade, so unless you really need the ultimate gear range I would opt for the Helix Plus cassette instead as it still offers a performance upgrade over Shimano and SRAM but is a good bit cheaper. After all, if you decide you want more range you can upgrade the Helix Plus to the 43-52t cluster at a later date. If weight saving rather than range maxing is what you're looking for, then you might be better off looking at the Garbaruk’s 12sp cassette as it shaves a further 50g (10-52t, XD) compared to the Helix Race.
| Attributes | Notes | Rating |
|---|---|---|
| Performance | Slick shifting and huge range | ★★★★★ |
| Construction | Excellent design although tolerances were tight | ★★★★ |
| Weight | Lightweight especially considering wider range | ★★★★ |
| Value for money | Expensive considering marginal gains over Helix Plus | ★★★ |
Tech specs: e*thirteen Helix Race 12-speed cassette
- Price: $379.95 / £319.95 / €348.85
- Sizes: 9-52t
- Options: XD only freehub
- Colors: Grey, Bronze, Naranja, Eggplant, Intergalactic
- Weight: 407g
