Advantages：

1.Surface treatment: using parkerizing  processing can not be rusty  and  long-term preservation
2.Material：20crmnti ，wear resistant  durable  and easy-processing  .Its carbon content is higher
3.R angle：Its can be perfectly moving well between the driving sprocket  and transmission chain .
4.Tolerance coefficient is small, less than the national standard.   Spline error is small, very good protection to protect shaft.
5.Improved bulge  three times, makes its no different sound, reasonable and beautifulappearance , to make the driving sprocket and rear sprocket   match in a line correctly  .
6.drill down at the same time ，makes it good look and High concentricity .
7.Using NC machine , the surface is flat and level .durable and movement more smoothly .
8.Using the  advanced imported gear hobbing machine,  make the gear groove more smooth .
9.Using  nitro-carbon titanizing and 0.8cm  to 1.2cm depth of surface hardening is great ，wear-resisting and durable .

Plate:45mn  pin:30crmnti  roller:20#   bushing:20mn   Rear Sprocket:45# steel ;                Front sprocket :20Crmo