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Old 08-25-2019, 08:19 PM
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itsid itsid is offline
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I'd swap to the much stiffer and sturdier aluminium cast backplate IIWY..
I'm not too confident that pressed sheet metal thingy is going to like a high weight/torque application too much..
It'll eventually fail IYAM.. and I'd swap it before it does

Anywhoo
yeah if the cam need 6500 to get into it's comfort zone.. you are pretty much screwed as of now.
that'd be ~82 mph on the current setup
and to reach such you'll need upwards of 21 horses.. which you certainly do NOT have
(and unlikely will be able to squeeze out of that engine)

So.. lowering the gear ratio according to your applied weight is the single option you are having
I suggest a lower than 6:1 ratio to be honest since you are not exactly skinny
nine tooth up front and 55 tooth on the wheel would make it a 6.11:1 ratio
and with 6500 rpms that would give you ~66mph
(IF you have upwards of 12 horses in that setup)
if you don't then your speed limitation will drop of course
exact same setup with just 10 horses might not allow you to reach more than 62mph
etc...
Oh forgot.. you loose 20% in the Tavkit
(Id say maybe even closer to 25%) so your overall power needs to compensate for that.
so ~16 horses for 66 mph and 13.5 ish for 62 mph etc...
[max speed is estimated and NOT based on gear ratio but on air drag at speeds alike!]

Sorry, that's not too good news is it?
And it get's worse.. if 6.5k is the minimum rpm for the cam to be of use..
that's not even going to cut it really.. is it?
you want 7000 rpm max at least to even see the cam doing anything.
and with that you need to gear even lower..
like 6.6:1 (9T tavkit-> 59T wheel) for a 16horse
and 7:1 (9T -> 63T) for the 13.5 horse

frankly.. what a stupid cam for a bike like that!

ah well...
I would swap to a much milder cam tbh and gear accordingly.


'sid
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