If it is rainy weather rust will occur in about half a year. It seems that we have to care for frequently because the backside welding part which is hard to see is especially rusty. The operation is fine without any problem.
Since the crank length of the current mamaari was 165 mm, I purchased it because I wanted to change it to 170 mm. However, although the number of teeth has been increased from 32 T to 36 T, I managed to never interfere with the full cover chain case. This is about 1000 yen is amazing Cospa.