Shimano CS4160 Nexus Sprocket (20T)

It fits perfectly on an old single speed coaster brake hub. It makes my beach cruiser noticeably easier to pedal into the wind and up hills compared to the old and worn 19 tooth sprocket it replaced. It delivers a nice, straight chain line with the concave side facing toward the hub. No problems with the part after 11 days and 261 miles of cycling. It's wonderful for local rides in town. Start and stop riding is easier. Merging up onto the highway is easier. Heavy cargo is carried smoothly. Climbs that used to be slightly strenuous are a breeze now. I think it's better for the bike not to stress the cranks and chain the way higher gears tended to do. It's easier to keep clean than the old sprocket. It's physically larger, so there's more clearance between the teeth and spokes for a gear brush and towel to remove road grime. After a few test rides and bearing cone adjustments, the bike rode silently with the new sprocket. Shimano did a great job manufacturing this product. It was shipped with a thin coating of oil, which I presume protected it in storage. I will definitely buy this brand again when the time comes. This sprocket starts to spin out the 44:20 drivetrain at around 18 mph, but I've gotten the bike up to 22.2 mph on a downhill run. My average speed is 10.5 mph, so I might try an even lower gear some day. It feels good to ride at 13 to 14 mph in tailwinds with minimal effort, so this 20 tooth sprocket is close to ideal.

Poor quality, material not hardened. Teeth wear out quickly.

Build quality is good exactly what I need for my clunker bike

Purchased for my Mongoose Beast and Mongoose Dozer. Pedaling is lighter over loose terrain - perfect for burning man. Replaces original rear sprocket. Only tool needed was a flat-head screwdriver to remove some sort of ring clip - check youtube for instructions. Original bike chain did not need to be modified or replaced - it has the correct number of links.

Shimano makes nice cogs and chainrings they are thicker than most which adds rigidity to the driveline. And they look good too.

Items it perfect looks good runs good the chain runs on it perfectly

Awesome replacement on your Mongoose Beast. It will make it easy to start of pedaling and seems like the proper gearing for the Beast.

This, plus 150mm cranks and 40t chain ring gives us the gear ratios needed for my wife's Raleigh Sports update. Sprocket is usable with 3/32 or 1/2" chain. Many thanks to excelcycle for good pricing and quick shipping and to Amazon.com for offering this item.