cmr 61mm user here, 1 month old, 2 torture long rides, no issues
for longevity and durability, go for vixion kit
consider the following:
cmr - 61mm (approx 180cc)
- steel
- price is affordable
- taiwan made
vxion - 57mm (approx 150cc)
- diasil
- price around 10k
- yamaha oem
just trying to compare hehehe, all will depends on your mechanic