FXR150: 428 vs 520 pitch chain/sprocket

[Flyingpony]

Stock they run 428 pitch chain/sprocket. Sprockets are front 14t and rear 49t. Sadly, the FXR doesn't have aftermarket (duplicate of genuine) sprockets made for it.

One bike shop said I could run a 520 pitch chain/sprocket. Apparently I'll then get a longer life out of the chain because with 250cc single they can get to 20-25k. ( My 428's reached 10k and died ).

Verified with other bike shops and they asked me "Why would you?"
To that I replied: "Got suggested it so I'm just wondering what you think about it".
Their reply: "A 428 is sufficent for a 150cc and has less drag (resistance), with a 520 there might not be enough clearance around front and rear chain guards etc".

So, are there any other FXR150's out there running 520 pitch?
And if so

1. number of tooth on front sprocket
2. number of tooth on rear sprocket
3. how did this impact on fuel economy
4. how did this impact on performance
5. how many k was it good for
6. other ...

This is just a question. Think I'll still put a 428 on, but then the rear sprocket will change to 47t. Not sure what impact dropping 2 teeth will be like. Know it'll be slightly higher geared but what kind of impact will it have?

What you other FXR's have running as number of teeth and what impact does this have on bike fuel consumption/performance?

Many thanks to you all!

[White trash]

I can get acc sprockets for an FXR150 so I'm not sure why the hell any other bike shop can't.

Go up a tooth on the front sprkt too, the engine will love you for it.

[DingDong]

most people try to light'n their drive... the 520 wont last any longer than the 428, It's your tension and alignment thats the problem.

Not that I know anything...

[erik]

The zeal runs a 428 chain. It seems it needs to be adjusted more often than my brother's zzr250 with a 520 chain, but it's not too bad. I don't know how a 520 chain would compare to a 428 in terms of service life or if they rob more power from the drivetrain.

Why would you want to go down 2 teeth on the rear (or up a tooth on the front for that matter, it'll have a similar effect)? Do you run out of revs before you run out of top speed?