You can determine the degree of wear stars shaped teeth.During the drive circuit operates only on the back side of the teeth, and therefore susceptible to wear it is this side.Each tooth on the new sprocket has a steep rear side, unlike the front.When you wear the front side does not change, and the back slightly "flattened", becoming flatter.Typically, resource cassette is about 10,000-15,000 km.This rate may be either higher or lower depending on riding style and class of equipment.At heavy wear of the teeth, the chain starts to slip during active movement of the pedals.
Wear system is about the same, with the change in shape of the teeth.On the front sprocket chain starts to slip during heav
y wear.The resource system is about 20000-25000 km, but badly worn chain may significantly reduce its service life.
chain wears faster than tape, with a difference of up to 4000 km.Wear circuit is in its pulled.To verify this, put a number of new and old chain.You will find that an equal number of units under tension old chain will be a little longer.
Pulling the chain occurs through wear axis units, and not because of the physical extension of its plates.In other words, the chain becomes loose.Thus, the distance between the links is changed, and there is a difference between the sprocket teeth and chain link length.
roulette or linear measure the distance between the center of coupling the first and 25th of the axes.The length of the new chain is 304.8 mm;in usable condition - 304,8-306,4 mm.With a length of 306,4-307,9 mm the chain is worn out.If the figure is even higher, so the chain is worn out very much.The replacement of worn parts is better to make a lump sum to avoid problems due to different steps cassette and chain.