Hi all, recently just fixup my 415 kit on my D390 on this new year.
I bought if from feburstore.com cant find any other source than this online seller. btw im from asia and it came nicely packed. im very surprised with the rear sprocket weight freaking light and the front is slightly lighter than the stock. quality wise its very good visibly i guess they had some good QC or finishing process.
So for you all just wana try get the feeling i suggest to get front sprocket of 19 due to clearance for the rubber part on the swingarm. but say if anyone can find out what you can replace this rubber on the swingarm to the most thinnest material possible i guess 16 teeth would fit nicely with a 1/4"~1/2" clearance when the chain is on tension. this i just a guess as in asia we had alot of small bike that we can convert to 415 kit and i had done it a few times.
Chain wise i made an error where my local shop dont have any 140+ length with Oring so end up i just gamble with 132 and it was too short. bought a 120l 2 pack and cut the chain to the appropriate length. with my current setup i counted you will need a min of 140 length. i think standard is 144 or smth i quite dont remember.
TAKE NOTE its a gear ratio of 2.8 means 19 front rear 53. was using a 520 kit of 15 & 43
All i can say its a day and night feeling on the low down but i have not tested how fast can it go now. TBH i never really tried whats the max speed, i would always stop at 140~150km/h with 2k rpm to spare till 10k and i know this bike still makes more power till 10k rpm. quite a brutal machine i would say.
i will post a photo soon maybe in the coming weeks, sadly no before and after.
next update will be me changing it to an o'ring chain. as i heard you can get more miles out of it compared to a roller type