A chain guard on the bike protects the legs and clothing from the dirty chain and prevents the pants comes between the chain and sprocket.
In addition, a fully enclosed chain guard can protect the chain itself from dirt and rain.
Chain guards come in three varieties:
- The closed chain guard where the chain is wrapped entirely.
- The chain guard that shields the chain at the top and at the chain ring.
- The chain ring ring that protects the chain on the chain ring.
Manufacturers mount on bikes without gears and bicycles with gear hubs usually completely enclosed chain guards. For bikes with dérailleur gears there are no closed chain guards. Although manufacturers present occasionally prototypes they have not yet succeeded in designing an elegant, well-functioning chain guard for the dérailleur system.
The efficiency of a chain decreases if it is poorly lubricated and dirt becomes between the links. By protecting the chain properly, it can be generously lubricated, and the lubricating oil is not washed away by the rain and dirt gets no chance to come between the links. A chain that is well protected less often needs to be lubricated, will wear out less quickly and has a higher yield.
A good chain guard ensures that maintenance is minimal to the chain and that the chain continues to run smoothly.
A malfunctioning chain has the opposite effect.
Water that is entering remains in the chain guard, washes away all lubricating oil and ensures that the chain gets corrosion. A chain guard that is hitting the chain creates additional efficiency losses.
Because the chain is not visible, the consumer does not see that the chain must be lubricated. A chain is difficult to remove from a enclosed chain guard as well as the chain guard itself.
Unfortunately, the chain guards used to be made so that they were very difficult to mount and quickly got damaged, giving them a bad reputation. Nowadays, the chain guard consists of a plastic upper and lower piece, and the assembly is much easier.
The chain guard is there for different wheel sizes. The size of the chain case is indicated by the sprocket size in inches. For bicycles available with a 33-tooth chainring, there are no closed chain guards. City bikes with a 33-tooth chainring from the Nexus group are therefore provided with an open chain guard.
The open chain guard is widely used on bicycles with derailleur gears for recreational and general use (the various types of hybrids).
Compared to the enclosed chain guard the chain guard has the disadvantage that it does not protect the chain against water and dirt.
In contrast, the chain is more easily accessible, the chain guard is easier to assemble and disassemble, the chain guard less damaging, the wheel is easier to remove and the chain guard less rubbing.
The chain is firmly put in brackets in the vertical or horizontal rear fork and the bracket.
The chainring is used mainly on bikes for sports use, such as mountain bikes and sporting hybrids.
The chainring offers far less protection than the chain guard.
The ring prevents that clothes can come between the chainrings and that the legs or pants are dirty when you hit the chain.