e*thirteen trsr 9-46t Cassette

The cog wars have recently been all about bigger. But e*thirteen has taken a slightly different approach. Their use of a 9t smallest cog allows for a smaller chainring without any loss of top end. If we compare an Eagle 10-50 with a 32t chainring we get a top ratio of 3.2 (with every complete crank rotation the rear wheel will rotate 3.2x) and a bottom gear of 0.64. With the e*thirteen TRS Race and a 32t ring those numbers become 3.55 for the top end and 0.70 for the low gear. Switch to a 30 and the TRSR gives you a 3.33 and 0.65 for a slightly higher top gear and an almost identical low gear.

You’ll need an XD Driver-compatible hub to mount this but e*thirteen says the cassette is compatible with both SRAM and Shimano 11spd drivetrain components. SRAM apparently did some testing and rejected the 9t approach because of the Polygon effect. As cogs get smaller there can be a shudder produced as the chain transitions from one cog to the next. SRAM felt this was enough to reject a 9t option and that 10t was a more sensible solution.

The Polygon effect may not be a big issue for me. For the riding we do around here the top gear is limited to riding the road to and from the trails, but this might be something to consider if your trails are fast and wide open and you know you’ll be parked in your tallest gear for long portions of your rides. We’ll let you know what we notice once we get some rides in.

A nice bonus of the TRS Race is the ability to replace either the aluminum or steel portions of the cassette individually. Tim Coleman has been testing the 9-44 version and he produced a tiny crack in one of the aluminum supports. The part will be returned to e*thirteen for analysis. They haven’t seen this from their customers apparently. The product is guaranteed against material and manufacturing defects for five years.

e*thirteen touts many benefits of stepping down from 10 and 50; a shorter chain, a potentially shorter derailleur cage for more clearance and less weight, more clearance because of a smaller chainring and a claimed straighter chain line when compared to Eagle. The performance of SRAM’s 10-50 has impressed us so it’ll be tough to beat

An Eagle 10-50t cassette will set you back US$425. An XT M8000 11-46 retails for US$110 while an XTR 11-40 11spd, with titanium, steel and aluminum cogs and a carbon spider, is only US$180. e*thirteen’s 9-46t cassette retails for US$349.95 and normally can be ordered online. e*thirteen sold out their current order almost instantly it seems. Until the middle of next month, your best bet is to ask your dealer to order one.

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But this one goes to 9…