I have just done a 520 conversion and a - 1 and + 2 sprocket change or so i thought. i ordered a driven conversion kit 15t and 48t with chain.
The original rear is 45t ( must be a uk thing) so i have gone up 3 on the rear.

My question is this. i feel a lot of resistance from the bike when off the throttle.
Like something is pulling me back.
Is that normal with this sprocket combination??

 

I would check your rear wheel alignment and your chain tension as I would assume it would be one of those.

 

by the end of the week i'll give you my input, i have a 15t and a 48t en route from 16t/46t stock.
you are saying if feels like you have more engine brake? because this is true and will happen.
you just went up about +6 in the rear from what you are used to, and if you don't mind, how is the acceleration? does the front wheel get light?

 

The acceleration is better and the front does feel lighter.
Still getting used to the change but is definitely getting resistance when
the throttle is off.
so chain tension and wheel alignment woud cause this issue.

 

It could, also make sure you have 520 sprockets.

 

Shorter gear ratio means harder accel and decel.
Letting off the gas in higher rpms should throw you forward in the seat anyways.

Make sure your wheels spin freely while lifted off the ground.

 

i have 15/48 on mine and the decel is very different from stock as well as accel.

 

just curious why you would say that. yes it is rarer to find those sprockets in 525 so one might make a mistake and mix match, but are you saying the heavier chain is an issue?
i've ordered 525 front and rear because i plan on using my existing 525 chain.

 

I was just mentioning that because if he has a 520 chain and 525 sprockets then the chain wont seat properly in the sprockets.

 

so i went -1 +2 (15,48) and i can't say that i feel much of a difference on engine braking at mid-low rpms if i chop it at high rpms im using the brakes too.
but i have noticed 1st gear will now power wheelie, and i dont think second gear will which is super awesome, it feels at the threshold, just have to stay out of trouble testing.