Cassettes with cogs as big as the large chainring on an old triple crankset have only been a thing since 2012, and while some riders are still unconvinced that a single chainring and cassette with a massive spread is best for them, OneUp is taking things a few steps further. The Squamish, B.C., company's 50-tooth Shark Cog and Shark Cage kit, which are only sold and designed to be used in combination with each other, give your Shimano eleven-speed drivetrain a 19% jump in range. In fact, OneUp says that the Shark Cog creates an 11 - 50 spread cassette with the widest range available when using a standard, non-XD freehub body.
The $125 USD kit includes the 50-tooth aluminum Shark Cog, an 18-tooth nickel-plated hardened steel cog, and the required high-offset Shark Cage for Shimano Shadow+ eleven-speed rear derailleurs. The large cog and derailleur cage are both available in either gray or OneUp's customary green color. Did you know that adult great white sharks have about fifty functioning teeth at any given time? The more you know... www.oneupcomponents.com
Shark Cog Details:
• Spread: 11, 13, 15, 18, 21, 24, 28, 32, 37, 42, 50
• Material: 7075-T6 aluminum (50t), nickel-plated hardened steel (18t)
• Compatibility: XT M8000 11 - 42 tooth cassette only
• Freehub requirement: standard freehub driver
• Cassette range improvement: 19%
• Colors: grey or green
Shark Cage Details:
• Pulley offset: 50% more than stock
• Compatibility: Shimano Shadow+ 11-speed derailleurs
• Crash replacement cages available separately
• Colors: grey or green
• MSRP: $125 USD for kit
The massive 50-tooth cog is so large that it makes the 42-tooth XT cog right next to it look small in comparison, but the Shark Cog wouldn't be possible if OneUp hadn't designed a new derailleur cage that bolts to Shimano Shadow+ 11-speed derailleurs. This is because the stock Shimano cage puts the upper pulley in a position that's designed to work with a 42-tooth cog, not the much larger 50-tooth Shark Cog, so OneUp's answer was to simply reposition the upper pulley wheel to provide 50% more offset relative to the cage's pivot point. The pulley wheel's new position is much more off-center of the derailleur cage's pivot (much like what SRAM has done on their 1X derailleurs), and it allows the pulley wheel to move further down and out of the way to clear 50-tooth cog when the cage is pulled forward by chain tension. And no, you don't need a different B-tension screw, and you'll likely find that you won't even need to dial your stock screw in all the way.
Installation and Setup
That isn't all, though. The upper pulley wheel's drastically offset position also means that it comes up closer to the small, 11-tooth cog when you're at the opposite end of the cassette. This provides more chain wrap and more security, but it also should help with shift speed at both the high and low ends of the range.
The gigantic 50-tooth cog weighs 92 grams, and the OneUp 18-tooth cog comes in at 24 grams, making for a weight increase of 73 grams over the 19-tooth (24 gram) and 17-tooth (19 gram) stock cogs that are getting ditched. OneUp's Shark Cage weighs 6 grams more than the stock, medium length XT cage, so you're looking at a total weight jump of 79 grams.
Do you have the tools and knowledge to remove and re-install a cassette? If so, you also have the ability to install the Shark Cog and 18-tooth steel cog onto your XT M8000 11 - 42 tooth cassette.
The 50-tooth Shark Cog sits right up against the back of the stock 42-tooth Shimano cog, so you simply slide that down into your freehub and then follow it up with the two Shimano carrier clusters (42, 37, 32, and 28, 24, 21). Now, instead of dropping on the separate 19 and 17-tooth Shimano cogs, you slide the OneUp 18-tooth steel cog and the stock Shimano spacer before the final three Shimano cogs. You've just ditched the stock 19 and 17 in order to run OneUp's 18 and 50-tooth cogs. Easy.
Your large cog was a 42 and it's now a 50, and that extra size means that you're going to need to either install a new chain or put a few links into the one you're already using. OneUp would prefer you to do the former, but adding a few links of chain is a pretty easy task. If your chain isn't long enough, and it probably won't be if you leave it at its original length, you risk causing some real carnage (a shark attack?) and incurring a hefty repair bill if you bottom-out your bike's suspension with the chain in the 50-tooth cog and it's not long enough to allow for that to happen. For this reason, always check chain length at bottom-out and when it's in the largest cog.
Installing the Shark derailleur cage is a bit more intimidating, but it's something that can be done in only a few minutes. It's best to do the cage before installing a new chain so you don't end up fighting its spring tension, and take note of which pulley goes on which end of the cage.
It also should be said that while Shimano generally remains quiet when it comes to this topic, you can bet your last eleven-speed quick link that they don't want you messing with their stuff. That doesn't mean that you shouldn't do it or that the OneUp conversion doesn't work well, but only that there are likely some polite Japanese engineers groaning when they see this. Oh, and you can forget about any sort of warranty on the derailleur.
I did run into one setup note that's worth mentioning: I installed a 34-tooth oval chainring with the Shark 50T Sprocket kit, and the drive-side crank does have to be spaced out a bit more than optimal in order for the ring to clear the Ibis Ripley's chainstay. This made for a chainline that was pretty out of alignment, enough so that the chain would drop off of the 42 tooth Shimano cog when I pedaled backward even though it was one in from being the largest cog. Interestingly, the chain wouldn't drop off the Shark Cog when rotating the cranks in reverse, despite it being even more out of alignment with the chainring. This is because the shift gates on the Shimano cog encourage the chain to drop off in order to quicken shift speed when going into a harder gear, whereas OneUp's cog features a different design. This foible is purely down to the chainline of my test bike.
I wonder what mountain bikers would say if you could travel back in time by a decade or so and tell them that 50-tooth cogs would be a thing in 2016? Would they call you an idiot, or would they say that they couldn't wait for a drivetrain that offers nearly as wide of a range as a two-ring setup but also one that I'd argue is much less complicated and refined? I think that it'd likely be split pretty evenly because, just like today, there are riders who aren't looking for the easiest possible gearing and enjoy pushing themselves on climbs, and there are just as many (or more) riders who just want to get up those same climbs.
I fall into the first category, so the idea of a 50-tooth cog appealed to me about as much as running a triple-ring crankset does, but then I turned down my attitude a bit and actually thought about it.
OneUp's 50-tooth cog might sound silly large, but you can easily manage your gearing by going with a larger chainring so that your easiest gear comes close to resembling what you had before, but the opposite end of the cassette becomes taller. So that's what I did. I went from a 30-tooth chainring to a 34-tooth oval ring, which meant that I instantly started using different cogs on the XT cassette than I would have otherwise. You can keep using the same chainring you had on pre-Shark Cog, but it makes far more sense to factor in the price of a new ring so as to adjust your drivetrain to the new, wider ratio.
The eight tooth shift from the stock 42-tooth cog to the 50-tooth OneUp cog is a big enough jump that my legs didn't really like that much. It wasn't the shift itself, mind you, but the actual eight tooth difference that just felt a bit odd to me when it came to matching my cadence and effort. Also, the larger chainring means that the gearing is obviously harder when the chain is in the 42-tooth cog, which is something that saw me make that eight tooth jump up on more than a few occasions while making my way up my steep local climbs.
Are you a numbers guy? For reference, the final jump on a SRAM XX1 cassette is six teeth (36 to 42), and the last jump on the pre-OneUp'd XT cassette is only five teeth (37 to 42). This means that the percentage of change between two largest cogs for the XX1 cassette is 16.66%, and the gap for the stock XT cassette is 13.51%. The OneUp'd XT cassette sees a much larger jump of 19.047%. Another number to keep in mind is the percentage spread between the highest and lowest cogs: the Shimano XT 11 - 42 is 281.81%, a SRAM XX1 10 - 42 and 320%, and the OneUp'd XT 11 - 50 cassette offers a wider 354.54% range.
Considering the Shark 50T Sprocket Kit? Decide if you want the 50-tooth as a "Holy shit, I'm dead" bailout gear and keep something close to your original chainring size, or get out that gear calculator and find out what chainring best suits you and your terrain.
Somewhat odd feeling gearing jump aside, the shift up to and off of the Shark Cog is remarkably quick and drama free. I was expecting some lag time - all of these conversions seem to be about 80 or 85% as quick as a stock setup - but the Shark 50T Sprocket kit is better than that. In fact, I'd go so far as to say that a lot of riders might never notice the difference in shift speed if they were to do a blind test, which is pretty remarkable given the eight tooth difference that the chain has to span. This is surely down to the Shark Cage and the offset upper pulley wheel that provides clearance but also locates the pulley in just the right spot height-wise. The setup even plays nice under high pedaling loads.
And speaking of high pedaling loads, the 34-tooh chainring and 50-tooth cog provided me with the gearing to get up anything that looked even remotely climbable. If you like to challenge yourself on steep, technical climbs and take pride in staying clipped-in when your riding buddies end up on their feet, the Shark 50T Sprocket kit could be ideal so long as you pair it with the correct size chainring. Pinkbike's Take:
|Put aside for a moment the idea of such a large cog being only for riders who just need to work on their fitness, even if there might be some truth in that. Am I unhappy with a stock Shimano 11 - 42 cassette? Not in the slightest, and I personally don't feel the need for an easier gear, but remember that the Shark Cog and Shark Cage allow a rider to greatly increase their gearing spread, and not only their low range but also their high range if they decide to go with a suitably larger chainring. This could be a real benefit to a rider with greatly varied terrain. - Mike Levy|
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