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 cassette. Compatibility: - Compatible with SRAM 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.

- 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

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

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.

At a full 5mm thick, the Surly Fixed Cog Lockring doesn't mess around with cog security. It's CNC-machined from premium stainless steel for serious strength and durability. This sucker will hold tight through hard sprints and crazy skids. It's a small part, but an important one and Surly makes it right.

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.

• Easy-on, easy-off • Available in two chain widths and two colors • Available in six teeth sizes

6-speed freewheel 14-28T SHIMANO Equivalent MF-TZ20

- 7-speed SIS compatible Freewheel - Shimano Equivalent: MF-TZ21

8-speed SIS compatible freewheel

- 3-spline steel cogs for use with Sturmey 3-speed (and 5-speed) internal gear rear hubs - Flat or dished for tuning chainline. Xylan coating for greater durability

- 3-spline steel cogs for use with Sturmey 3-speed (and 5-speed) internal gear rear hubs - Flat or dished for tuning chainline. Xylan coating for greater durability

SRAM's PG-730 7-Speed Cassette is the perfect replacement for your worn-out gears. It features a rugged steel construction for awesome durability and SRAM's PowerGlide technology for smooth, precise shifts throughout its 12-32 tooth range.

SRAM's PowerGlide PG-820 Cassette is a fine 8-speed cassette. It features steel cogs with SRAM's DuraBlast technology for smooth, precision shifting and excellent durability.

SRAM's PowerGlide PG-830 Cassette is a quality 7-speed cassette. It boasts durable chrome-plated steel cogs with SRAM's shifting technology that includes optimal tooth profiles and ramps for fast, precision shifts every time.

When it's time to replace your old 8-speed cassette, check out SRAM's PG-850. Its steel construction and SRAM's PowerGlide technology combine to deliver miles of solid shifting and outstanding durability.

No mixed messaging or compromises here. The GX DH cassette was built with only one purpose in mind—exploiting gravity to its fullest lap after lap. This downhill-optimized 7-speed cassette provides gear steps that give each shift more purpose, and its compact design allows more spoke clearance. It’s a full-on, dedicated SRAM 1x cassette for gravity that lets you keep some money for a lift ticket. GX DH—Get Some. - The PG-720 cassette is an integral part of the SRAM 1x DH drivetrain system - This is the most affordable full-featured, dedicated 1x DH cassette in the industry - Fewer cogs allow for a faster transition from starting cog to highest cog - More rear wheel clearance around spokes - Fully compatible with the SRAM X01 DH drivetrain - Splined driver body compatible - Weight: 224 grams - Gear-Ratio:11-25t - Speeds: 7 - Recommended Group: GX DH

When it's time to replace your 9-speed cassette, check out SRAM's PG-950 cassette. It delivers solid shifting and durability ride in and ride out for your 9-speed rig.

SRAM's PG-970 9-Speed Cassette is the perfect replacement for your worn-out gears. It features a rugged steel construction for awesome durability and SRAM's PowerGlide technology for smooth, precise shifts.

SRAM's PG-1130 11-Speed Cassette is constructed of heat-treated steel cogs and boasts SRAM's PowerGlide tooth profiles and shift ramps for quick, positive gear changes. This excellent cassette also sports an aluminum spider construction for a maximum stiffness-to-weight ratio, a durable steel lockring, and comes in three wide ranges to suit your riding style.

SRAM's PG-1030 10-Speed Cassette is a great choice. It's constructed of light and durable materials and boasts SRAM's PowerGlide tooth profiles and shift ramps for quick and positive gear changes every time. This trick cassette is available in four configurations perfect for riding off road, including one with a 36-tooth largest cog for super-easy climbing.

SRAM's PG-970 DH 9-Speed Cassette is the perfect replacement for the worn-out gears on your downhill or freeride bike. It features a rugged steel construction for awesome durability and SRAM's PowerGlide technology for smooth, precise shifts.

SRAM's 1050 10-Speed Cassette is a great choice. It's constructed of light and durable materials and boasts SRAM's PowerGlide tooth profiles and shift ramps for quick and positive gear changes every time. This trick cassette also sports a semi-spider construction for a maximum stiffness-to-weight ratio and is available in myriad configurations to suit all your riding. There are even models with 36-tooth largest cogs for super-easy climbing.

When it's time to replace your 9-speed cassette, check out SRAM's PG-980 cassette. It delivers solid shifting and durability for your 9-speed rig.

SRAM's PG-970 9-Speed Cassette is the perfect replacement for your worn-out gears. It features a rugged steel construction for awesome durability and SRAM's PowerGlide technology for smooth, precise shifts.

SRAM's 1170 11-Speed Cassette is constructed of light, durable materials and boasts SRAM's PowerGlide tooth profiles and shift ramps for quick, positive gear changes. This excellent cassette also sports a semi-spider construction for a maximum stiffness-to-weight ratio, a lightweight aluminum lockring, and is available in three ranges to suit all your riding.

SRAM's 1070 10-Speed Cassette is a great choice. It's constructed of light and durable materials and boasts SRAM's PowerGlide tooth profiles and shift ramps for quick and positive gear changes every time. This trick cassette also sports a semi-spider construction for a maximum stiffness-to-weight ratio, a lightweight aluminum lockring, and is available in myriad configurations to suit all your riding. There are even models with 36-tooth largest cogs for super-easy climbing.

Get reliable shifting in a sweet lightweight package with SRAM's PG-990 9-speed cassette. It meet the demands of mountain bikers everywhere, from elite racers to weekend trail riders. Cut from steel with an aluminum spider, the 990 is light, durable and shifts flawlessly. Tested on the pro circuit. Proven on your local ride.