the eagle is no longer a protected species
WHEN SRAM’S EAGLE SYSTEM CAME OUT A COUPLE YEARS AGO, IT WAS THE FIRST time a drivetrain with a single chainring could boast as much range as popular multi-ring setups, effectively putting the last nail in the front derailleur’s coffin. To do it, SRAM decided to add a gear, making all Eagle groups a 12-speed affair. Sure, they could probably have done it with 11 gears, but then they’d be selling people one new part instead of five new parts. Adding a gear was a good business move.
Don’t get me wrong, I’m a fan of Eagle—I’ve given my last few ground-up builds the bird. The stuff works well, and it’s now more affordable than ever, but what if you already have an 11-speed bike that you want to get more range out of?
In the following pages, you’ll read about two of our preferred ways to get more range out of your 11-speed system. E*thirteen’s TRS cassette mounts to a SRAM XD driver body and uses a 9-tooth cog to get its 511-percent gear range, while One Up’s 50-tooth Shark Sprocket kit extends the range of Shimano 11-42 cassettes. Whichever one works for you and your current setup, it’ll keep you pushing those 11-speed triggers until they’re clicked out.
One Up 50t Shark Sprocket and Cage | $125
If you buy a Shimano single-ring bike off the showroom floor today, it’ll probably come equipped with Shimano’s newer, wider-range 11-46-tooth cassette, but there are still a ton of SLX and XT 11-42 cassettes out in the world. Normally, my advice would be to stay as far away from cassette add-ons like this One Up 50-tooth Shark kit as possible, no matter how much extra
range they boast. The engineers at Shimano work really hard to make their components shift as perfectly as possible, and I’ve gotten burned by jamming random CNC’d parts into the system before— that Kooka crank might have looked radder than my stock STX-RC one, but it dropped chains faster than DJ Jazzy Jeff could drop a beat.
You can imagine then, how infuriating it was for me when this thing I really wanted to make fun of actually worked. I mean, I’m supposed to cannibalize a perfectly good Shimano derailleur and bolt on some CNC’d cage? I don’t think so. The fact that I’d gladly recommend the 50T Shark kit to my closest friends brings me zero happiness whatsoever. I don’t like being wrong.
Typically, slapping a giant cog on the back of the cassette results in poor shifting over the entire cluster. That’s because getting the derailleur to shift up into that new big-ass cog requires screwing in the b-tension so much that the guide (upper) pulley runs too far away from all the other cogs. The general rule is, the farther away the guide pulley is from the cogs, the slower and less precise the shifting gets.
This is why One Up sells this as a kit with a derailleur cage instead of simply a cog add-on. The One Up cage repositions the guide pulley so it can clear the 50-tooth cog while still running close enough to the
smaller cogs for quick, precise shifting.
The Shark Cage is a huge contributor to the efficacy of the kit, but the extra cogs themselves are doing some heavy lifting too. The kit comes with two of them. In order to add the 50-tooth to the back of the cassette, you need to make room for it by removing a cog. But if you simply remove one, you’re left with two things: a larger-than-desired shift, and mismatched shift ramps. If you look closely at a cassette you’ll see how the shift ramps match up between the cogs to deliver the chain smoothly to each.
So, when installing the cassette, you leave out Shimano’s 17- and 19-tooth cogs, using One Up’s 18-tooth instead, which matches shift ramps, tooth shape and finish so well that if ‘One Up’ weren’t stamped into the steel, you’d be hardpressed to identify it as non-Shimano. The 50-tooth is beautifully done as well, in 7075 aluminum hardened to a T6 temper, with perfectly matched ramping and eight upshift opportunities per revolution.
It’s not the typical hodgepodgery that we’ve seen in a lot of other cassette expanders. I’ve noticed little-to-none of the shift degradation that normally accompanies these types of modifications. And after about 1,000 miles, some of which were on an e-bike (judge me if you want to), the alloy sprocket has plenty of life left in it.
Shimano derailleur cage with the Shark Cage is simple for anyone with some mechanical aptitude and, once installed, it’s adjusted like any other derailleur. One Up even has thorough instructions on its website to guide users and shop mechanics through the process.
Before you go ordering the kit, though, make sure it’s compatible with what you’ve got. This thing works so well because it’s designed to interface specifically with the SLX M7000 and XT M8000 11-42-tooth cassettes. It won’t work with anything else, so don’t go trying to run it on 40- or 46-tooth cassettes. The Shark Cage is compatible with M9000, M8000 and M7000 derailleurs. Also, keep in mind you’ll need a new chain and a bigger chainring. How much bigger is up to you.
You could go up by four teeth while maintaining the low gear you already have, but I like going up two teeth because it yields both higher high, and lower low gears.
This kit offers an impressive, cost-effective way to get a lot more range out of your 11-42 cassette. To be specific, 19 percent more, netting you a 454-percent range. It’s so impressive that I’m willing to eat my words. If you’ve already got some compatible parts, this thing is definitely worth the dough.
It’s not the typical hodgepodgery that we’ve seen in other cassette expanders. I’ve noticed little-to-none of the shift degradation that normally accompanies these types of modifications.
e*thirteen TRS Plus Cassette | $250
The e*thirteen TRS Plus Cassette isn’t a new product altogether, but its gear range has just been widened to 511 percent, a range previously only found on the TRS Race. What you’ll get, aside from an extra Benjamin in your pocket, is essentially the same. The TRS Plus has the exact same 9-46 tooth, 11-speed ratio, but different construction makes it a whopping 36 grams heavier. Of course, that’s still 17 grams lighter than SRAM’s X01 Eagle cassette.
What you’ll get by swapping your SRAM 11-speed cassette for this one is Eagle-beating range for $250, without needing to plunk down for an entirely new 12-speed drivetrain. Of course, you’ll probably want to swap out your chainring for a smaller one, and replace that scrappy old chain while you’re at it, so you’ll want to consider that in your budget.
How do these e*thirteen TRS Cassettes have 11-percent more gear range than SRAM Eagle, with just 11 speeds and no giant 50-tooth cog? It’s that little 9 tooth at the bottom. With so few teeth, a one-tooth change represents a larger gear jump than, say, a fourtooth jump up higher on the cassette. So, where SRAM Eagle provides a lower low gear, e*thirteen focused on the high end. This is particularly good because it means you can run a smaller chainring, which means better frame and ground clearance.
There are a fair amount of bikes out there that’ll only accept up to a 32-tooth, which on an
Eagle drivetrain, might be too small for strong riders.
To achieve the 9-tooth small cog, e*thirteen had an engineering hurdle to overcome, namely how to get it on a wheel. Since the
9-tooth is such a small diameter, a normal cassette tool fitting wouldn’t work, which birthed e*thirteen’s ingenious solution. The first three easy cogs, which are crafted from aluminum, get mounted to an XD driver body by way of what looks a lot like a bottom bracket lockring and a corresponding proprietary tool. After I finished testing the TRS Plus Cassette, e*thirteen swapped that lockring design for a pinchbolt. Then the remaining cluster of
eight cogs, machined from one piece of steel, notches into that by using a chain whip. Being made out of aluminum, the three large cogs are more susceptible to wear than their steel neighbors, so you’ll be able to replace each of the two cluster components independently.
Considering how many patents drivetrain giants SRAM and Shimano collectively own around how chains and cogs interact with each other, e*thirteen did a good job creating a nice-feeling shift. They’ve struggled a bit with creaking issues where the aluminum and steel parts contact one another, which a generous slathering of grease usually wipes out. The only other difficulty is that, to remove the cassette, you’ll need to add a second chain whip to your tool collection.
And then there’s the relatively bigger issue that the tiny 9-tooth cog generates. A chain will run smoother on cogs with more teeth and rougher on cogs with fewer ones. Since the pitch of the chain is constant, the links can only bend at fixed points, so once you get smaller than a certain number of teeth, the chain has a tougher time bending around the cog and the rollers in the links might not land right at the bottom of the tooth wells where they’re supposed to. This causes vibration which, to the rider, feels like a rough gear, and it could also cause premature chain wear. For all kinds of science-y stuff, Google ‘chordal action’ and ‘polygon effect.’ This, according to SRAM, is why Eagle goes to 10 teeth instead of nine.
But for many riders, the benefits might outweigh the costs here. You can definitely feel that the chain doesn’t run quite as smoothly in the 9, but if you geared your chainring properly for your needs, you won’t be in that cog all day. Plus, most riders aren’t likely to be laying down extreme amounts of torque in that gear anyway, so that roughness likely won’t have a detrimental impact on performance for most.
What you’ll get by swapping your SRAM 11-speed cassette for this one is Eagle-beating range for $250, without needing to plunk down for an entirely new 12-speed drivetrain.