We did our homework on this cog and we think you will be pleased with the result! This 16t cog smooths out the cog to cog transition when using our GC and a standard 10 speed 11-36 cassette. You should expect this to shift well and last as long as the rest of your cassette cogs of similar size. Here are the transitions WITHOUT the 16t cog (4 tooth max jump): - Remove the 15t -> 11-13-17-19.... - Remove the 17t -> 11-13-15-19... Here are the transitions WITH the 16t cog (3 tooth max jump): - Remove 15t & 17t-> 11-13-16-19... Compatibility: Shimano 10 speed cassettes - XT 11-36t (CS-M771) - XTR 11-36t (CS-M980) - Other 11-36t Shimano cassettes like SLX HG81 11-36t - Modification required (must drill out rivets holding the 17t to the larger cogs) SRAM 10 speed cassettes - PG 1030, 1050, and 1070 - 11-36 and 12-36 - X0 11-36t(XG - 1080) - Remove the 14t rather than the 17t

The GC line of cassette extender cogs allow you to modify your 10 speed cassette into a wide range cassette. To achieve the optimal shifting, the GCs are optimized for Shimano or SRAM cassettes. Compatibility: - Compatible with Shimano 10 speed cassettes - Compatible with all 10 speed rear derailleurs and chains - Note that you may need a longer chain that you currently have on your bike - Chain stretch should be less than .5 when installing a new GC - Can be run in 2x configuration with a long cage rear derailleur - These fit very tight on certain Stan's No Tubes hubs like the 3.30 and the Easton X4 hubs. With a little filing and some grease they will go on.

The product that set the standard and still the best available! The GC line of cassette extender cogs allow you to modify your 10 speed cassette into a wide range cassette. To achieve the optimal shifting, the GCs are optimized for Shimano or SRAM cassette so always select the correct type for the cassette brand you have. Compatibility: - Compatible with SRAM 10 speed cassettes listed on the GC tech page - Compatible with all 10 speed chains - Note that you may need a longer chain that you currently have on your bike - Chain stretch should be less than .5 when installing a new GC - Compatible with all 10 speed rear derailleurs except non-clutch type SRAM rear derailleurs model year 2012 and older - These older rear derailleurs do work with the GC40. - Can be run in 2x configuration with a long cage rear derailleur - These may fit tightly on some over-sized hub bodies such as Stan's No Tubes 3.30 and the Easton X4 hubs. With a little filing and some grease they will go on.

The product that set the standard and still the best available! The GC line of cassette extender cogs allow you to modify your 10 speed cassette into a wide range cassette. To achieve the optimal shifting, the GCs are optimized for Shimano or SRAM cassette -- always select the correct type for the brand of cassette you have. Compatibility: - Compatible with Shimano 10 speed cassettes listed on the GC tech page - Compatible with all 10 speed chains - Note that you may need a longer chain that you currently have on your bike - Chain stretch should be less than .5 when installing a new GC - Compatible with all 10 speed rear derailleurs except non-clutch type SRAM rear derailleurs model year 2012 and older - Can be run in 2x configuration with a long cage rear derailleur

- Extended range aluminum cog for those wanting 1x10 with a full range of gears - Only fits Shimano XT/XTR 11-36t (M771/M980) or SRAM X5/X7/X9/X0 11-36t 10sp cassettes (not compatible with 2011 and older SRAM derailleurs) - Requires removal of the 17T or 15T cog and spacer from existing cassette - Longer B-screw (sold separately) only needed for about 50% of Shimano derailleurs - May require a longer 10sp chain. Very tight fit on Stans 330 rear hub splines - Designed and manufactured in the USA from 7075-T6 aluminum alloy

- Allows the use of a 7 speed shimano cassette on an 8 or 9 speed shimano cassette body

Pair this cog with your Shimano-compatible rear hub, spacers and a lockring (sold separately) and discover the joy and simplicity of a singlespeed without the cost of a new wheel. Machined from heat-treated chromoly and then chrome plated, these seriously tough cogs are strong, shiny and they come in sizes from 13T to 22T so you can pick the perfect gear.

Machined from heat-treated, chrome-plated chromoly, these seriously tough cogs will hold up to massive track sprints and crazy skid-stops. Surly's Track Cogs are strong, shiny and they come in two widths and sizes from 13T to 22T so you can select the perfect gear.

- Fluid Drive Plus shift profiling, compatible with SRAM and Shimano 8sp drivetrains - Steel rings, engineering polymer spacers, nickel plated finish - 12-25 - 281g

- Fluid Drive Plus shift profiling, compatible with SRAM and Shimano 9sp drivetrains - Steel rings, engineering polymer spacers, nickel plated finish - 11-28 - 280g

Shimano's 105 10-Speed Cassette delivers excellent shifting and durability. The cogs are made of long-lasing, smooth-running steel. They have Shimano's engineered tooth shapes for precision shifting. And for lightness, the cassette has an aluminum carrier for the top cogs and nylon spacers.

- MODEL NO: CS-HG700-11 - SERIES: SHIMANO 105 R7000 Series - Average weight: 379 g - Combination: 11-13-15-17-19-21-23-25-27-30-34T - Combination name(Group name): 11-34T - Compatible chain: HG-EV 11-speed/HG-X11 - Speeds: 11-speed - Spider arm_QTY (pcs): 1 - Type: HG-EV

- MODEL NO: CS-R7000 - SERIES: SHIMANO 105 R7000 Series - Average weight: 284 g (11-28T), 304 g (11-30T), 320 g (11-32T), 269 g (12-25T) - Combination: 11-12-13-14-15-17-19-21-23-25-28T, 11-12-13-14-15-17-19-21-24-27-30T, 11-12-13-14-16-18-20-22-25-28-32T, 12-13-14-15-16-17-18-19-21-23-25T - Combination name (Group name): 11-28T, 11-30T, 11-32T, 12-25T - Compatible chain: HG-EV 11-speed/HG-X11 - Speeds: 11-speed - Spider arm QTY (pcs): 1 - Type: HG-EV

- Special single gear design with chain tensioner - Revised tooth profile to prevent chain skip - MODEL NO: CS-S500 - SERIES: SHIMANO ALFINE S7000/S700 Series - Gear thickness (mm): 2.0 - Recommended chain: Super Narrow HG for 9-speed - Gear Teeth: 18T, 20T

- MODEL NO: CS-HG400-9 - SERIES: SHIMANO ALIVIO M4000 Series - Compatible chain: HG 9-speed - Speeds: 9-speed - Type: HG

- Cassette Body Type: Shimano/SRAM 8, 9, 10 Speed - Drivetrain Speeds: 8

- MODEL NO: CS-HG201-9 - SERIES: SHIMANO ALTUS M2000 Series - Combination: 11-13-15-17-19-21-24-28-32T (bo), 11-13-15-17-20-23-26-30-34T (bn), 11-13-15-17-20-23-26-30-36T (bw), -, -, -, - - Combination name(Group name): 11-32T (bo), 11-34T (bn), 11-36T (bw) - Compatible chain: HG 9-speed - Speeds: 9-speed - Type: HG

- MODEL NO: CS-HG41-7 - SERIES: SHIMANO - Combination: 11-13-15-18-21-24-28T (ac) - Combination name(Group name): 11-28T (ac) - Compatible chain: IG/HG - Speeds: 7-speed - Type: HG

- MODEL NO: CS-HG50-8 - SERIES: SHIMANO CLARIS R2000 Series - Compatible chain: CN-HG71 - Speeds: 8-speed - Type: HG

Shimano's Claris cassette is an incredible value for your 8-speed drivetrain. This cassette comes in a range of sizes to suit your riding style and terrain.

- MODEL NO: CS-HG500-10 - SERIES: SHIMANO DEORE M6000 Series - Combination: 11-12-13-14-15-17-19-21-23-25T, 12-13-14-15-17-19-21-23-25-28T, 11-12-14-16-18-20-22-25-28-32T, 11-13-15-17-19-21-23-26-30-34T - Combination name (Group name): 11-25T, 12-28T, 11-32T, 11-34T - Compatible chain: HG-X 10-speed/HG 10-speed/CN-HG500 - Speeds: 10-speed - Type: HG

- MODEL NO: CS-HG50-10 - SERIES: SHIMANO DEORE M6000 Series - Combination: 11-13-15-17-19-21-24-28-32-36T (bk) - Combination name (Group name): 11-36T (bk) - Compatible chain: HG-X 10-speed - Speeds: 10-speed - Spider arm QTY (pcs): 1 - Type: HG

• Steel construction on all but the largest aluminum gear • Nickel-plated finish for corrosion and wear resistance • Dyna-sys 11-speed cassette with "Rhythm step" gearing for closer gear ratios and smoother shifting performance • Fits Dyna-sys 11-speed and current Shimano 9/10-Speed MTB hubs • The largest cog (40t) is positioned inboard and above the drive-side flange • Hubs with tall drive-side flanges may not be compatible due to spoke interference

Reliable, perfect shifting awaits with Shimano's Deore XT Dyna-Sys Cassette. It features chrome-plated steel sprockets mounted to two aluminum carriers for an ideal blend of durability and low weight. Closer gear ratios in the middle of the cassette ensure you'll have the perfect gear for the trail's ups and downs. Plus, the cogs are ramped and machined for flawless, lightning-fast shifts.

Shimano XT CS-M770 9-Speed Cassette - Aluminum carrier reduces weight and increases rigidity - Cassette Body Type: Shimano/SRAM 8, 9, 10 Speed - Drivetrain Speeds: 9 - Weight: 323 grams

Shimano Cassette Lockrings

Shimano's Dura-Ace 10-speed Cassette is comprised of an aluminum cog carrier, 4 titanium and 6 steel cogs (from largest to smallest respectively). This makes for a super-light and stiff cassette that makes your derailleur shift like a dream so you can dance up the climbs as easily and efficiently as your chain climbs up and down these cogs.

Shimano's Dura-Ace 11-speed Cassette is comprised of two aluminum cog carriers, 5 titanium and 6 steel cogs (from largest to smallest respectively). This makes for a super-light and stiff cassette for perfect shifting so you can dance up the climbs as easily and efficiently as your chain climbs up and down these cogs.

Shimano Cassette Lockrings.

- Rider Tuned Gearing - Wider Gear Combination: 11-28T/12-28T/11-30T (New Gear Combination) - Closer Gear Combination: 11-25T/12-25T - Lightweight - CFRP & Alloy Spider Arm, 5 Titanium Sprockets - Gear Combination: 11-25T, 11-28T, 11-30T (New Gear Combination), 12-25T, 12-28T