Change your chain before it becomes too stretched to avoid unnecessary wear to the cassette and chainrings. Dave Caudery / Our Media

Bike Chains | Mountain Bike Chain | Chain Reaction

Both an 18- and 21-speed bike have three chainrings in the front, but the 18-speed has six cogs in the rear while the 21-speed has seven, according to Popular Cyclist. However, an 18-speed bike can also have two chainrings in the front and nine cogs in the rear. The latter option tends to offer a bit more speed and power than the former.Derailleur:‌ A mechanism controlled by your shifters (below) that moves your bike chain from one gear to another. Most bikes have derailleur in the rear, but not all have one in the front. There may be a small metal "tab" between the 2 small pulleys in your derailleur. The chain must pass this tab without rubbing on it. Bike efficiency depends on the pitch difference. For a higher pitch difference, you will get a loose chain setting and it will decrease your bike speed eventually. This KMC bike chain is stretch-proof and is able to withstand a little more wear and tear which means you can get more mileage of the bike chain. If you ride a BMX bike, the chain you choose is going to be different than road or mountain bikes. A majority of BMX bike chains are much narrower than road or mountain bikes; BMX chains measure at ⅛” width.

Quick Answer: What Chain For 21 Speed Bike - BikeHike Quick Answer: What Chain For 21 Speed Bike - BikeHike

Regular adjustment of the derailleurs and chainrings is also important in keeping the gears shifting smoothly and reducing the risk of damage to the derailleurs and chainrings. Even the phrase “21 speed” is a little deceptive. To be more accurate, for each “speed,” you could pedal along at the SAME miles/hour on your bike. It’s important to keep the chain well-lubricated and free from dirt and debris to ensure smooth shifting and efficient power transfer. Shifters Many cyclists size their chains by running the chain through the front derailleur and then drape the chain over the big chainring in the front and the big cog in the rear.The number of gears, gearing system used, and weight of the bike are key factors that set 21-speed bike gears apart from other types of bike gears. Number of Gears It's important to take the time to select the right size bike chain for your bike type because if you put the wrong chain or even one that doesn't fit quite right, you could end up doing damage to your bike. You can switch between these chainrings using the front derailleur, which allows for even more gear ratio options. How do 21-speed Bike Gears Differ from Others? If you don’t want to visually observe/compare the lengths of the former chain to the replacement chain, you can just count the number of links the former chain has, and customize the replacement chain based on that. 2. Try the Chainring Method Within the 21-speed bike gear system, there are different types of gear available, including traditional, cassette, and single options.