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  • Wolf Tooth Components Giant Cog for Shimano
  • Wolf Tooth Components Giant Cog for Shimano
  • Wolf Tooth Components Giant Cog for Shimano
  • Wolf Tooth Components Giant Cog for Shimano
  • OptionsWolf Tooth Components -
  • Wolf Tooth Components -
  • Wolf Tooth Components -
  • Wolf Tooth Components -
Wolf Tooth ComponentsGiant Cog for Shimano
$74.95 - $79.95

Item # WFC0003

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  • Black, 40T ($74.95)
  • Black, 42T ($79.95)
  • Blue, 42T ($79.95)
  • Red, 40T ($74.95)
  • Silver, 40T ($74.95)
  • Silver, 42T ($79.95)
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Item # WFC0003

The solution.

You’ve approached the climb at Gates of Hell dozens of times. You’ve studied every possible line. You’ve eaten raw eggs. You’ve played the themes from several action hero movies during your attack. Nothing works — the climb shuts you down every time and you wind up pushing to the top with your virtual tail between your very real, very worn-out legs. Forget about testosterone shots — maybe the answer is just an adjustment to your drivetrain. Meet the Wolf Tooth Components Giant Cog For Shimano. So, how giant is GIANT?

40 or 42. That’s not a typo — 40 or 42 (your choice) teeth on your cassette. You could climb a tree with this thing. These days, most drivetrains have gone to a single or double up front and a larger cassette. This seems to be a winning combination for most folks, but there are those whose local terrain needs a bit more torque to conquer. Bear in mind — the Wolf Tooth Giant Cog For Shimano only works with Shimano 10spd XT or XTR cassettes. The shift points are properly timed to the tooth locations on the 36T Shimano cogs. Also, use of this cog requires the removal of the 15T or 17T cog and spacer from your cassette. You will probably also need a longer chain.

Tech SpecsWeight
Tech Specs
Cog Sizes
40 t, 42 t
Recommended Use
mountain biking

Actual Weight

Actual weights are measured in-house by the Competitive Cyclist team.

Have questions? Chat with a Gearhead



Black, 40T
Black, 42T
Blue, 42T
Red, 40T
Silver, 40T
Silver, 42T

Claimed Weight

Claimed weights are provided by the vendor.

Have questions? Chat with a Gearhead

86 g

Reviews & Community


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Revamp your 10 speed

  • Familiarity: I've used it several times

Was abile to revamp an old 10 speed mountain bike with this creating a good range of 1 x. I used the 40 tooth as it will give you better more consistent shifting.

Just enough extra gear

  • Familiarity: I've used it once or twice and have initial impressions

I recently upgraded to a new wheel set and saw the opportunity to increase my climbing capability by adding a 42 tooth ring from my OEM 36 tooth. I ride in the high country of Colorado and climbs at 11,500 ft. are not uncommon. The 42 tooth ring was just the right amount of gear to continue to ride instead of the old hike a bike to the top. I'm no mechanic but got advice from the gear heads, ordered a cassette wrench and I was riding the next day. Shifts super smooth and minor adjustments to the X2 OEM set up to make it work. I have about 15 miles on the new set up and I'm sold. Great upgrade. I'm in my 50's and live at 8000 ft and this makes most of my climbs possible if I can make the technical moves.

Best option to expand your gear range!

  • Familiarity: I've put it through the wringer

Recieved this about 6 months ago and have ridden it many miles of singletrack since. Has provided me with great performance since and I've had no complaints whatsoever!

Best option to expand your gear range!

Great upgrade!

  • Familiarity: I've put it through the wringer

After deciding to ditch my front derailleur I needed something to get my granny gear back. I paired this up with a Shimano XT Dyna-Sys CS-M771 Cassette and now I have a climbing gear again. The install was very easy and I opted to remove the 17 tooth gear without getting the 16 tooth. I have not had any issues with shifting and the whole setup is very crisp throughout the gears!

Great cog, easy to install

  • Familiarity: I've put it through the wringer

I bought the 40t and it went right on and even had enough chain . Shifts really well and has made a difference when it gets really steep.

Wide Range on the Cheap

  • Familiarity: I've put it through the wringer

Buy this. It is great. If you would like to know more read on.
No need to get some fancy 11 speed. Use the derailleur, shifter, freehub, chain, and cassette you already have. Just slap this Giant Cog on and you be partaking of that sweet wide range nectar.

Easy to install. As long as you have a cassette lockring tool and a chain whip. If not take this and your bike/rear wheel to your local bike shop and they will be able to install it. Make sure your rear derailleur will accommodate the tooth change from your smallest cog to your biggest cog. You may also need to lengthen your chain after installing.

To install the WTC Giant Cog you have to remove either the 15T or 17T cogs from your cassette. I would recommend you remove both and replace them with the 16T cog from Wolf Tooth components. It is pretty cheap and will give you a much more consistent jump between gears. Make sure your cassette is compatible with the Giant Cog. Also, make sure you buy the correct Giant Cog for your cassette brand.

The cog functions great. Shifts smooth and feels like a normal gear, just much lower. I got the 42T. I would recommend this size. If you are looking for the lowest gear possible, go with the 42T. You won't regret it. I used mine with a Shimano 11-36 XT Cassette. The XT and XTR cassettes are compatible without modifications. I think you can also use it with the SLX cassette with a slight modification. Check out for more information.

If using a Shimano Shadow + derailleur like I did (I used an SLX derailleur but it works with other Shimano derailleurs), I would recommend getting the GoatLink by Wolf Tooth Components and Lindarets. See their website for compatibility. Google can help you get there. It replaces the little link on the derailleur that attaches the derailleur to the hanger. It improves the position of the derailleur improving shifting. With the GoatLink shifting into the 42T cog felt just like shifting into any other cog. I have heard that Sram derailleurs work without any fancy links, but I have not tested one to know for sure.

I used this with a 1x10 set up with a narrow wide 30T front chainring. With the giant cog I was able to climb anything on Slickrock. It also made my local trails in Upstate Utah much more rideable. This single product significantly cut down on the number of hike a bikes and make my legs last much longer. I'm being serious.

With the price of the Giant Cog, the 16T cog, and the GoatLink things start to add up, but it is still much cheaper than converting to a 1x11 setup. Much much cheaper and easier. I am a converted to the wide range 1x10 gospel and I want to spread the joy I have found with others. Get your range back while still living the simple 1 by life!