do they really give a power increase? i'm due for a cambelt change soon so i was wondering if its worth changing the pulley?

 

No they don't, the reciprocating mass is reduced though which theoreticaly should improve engine response.

bob

 

theres one on mine, looks nice, that much i am 100% on
the rest.......

i have no idea, but what bob says is sound
should help heel and toe?

the GGR website claims you gain power, tho i belive this is for under driven pulleys?
not sure if mine is underdriven TBH

 

found this page

maybe worth a read
http://www.unorthodoxracing.com/faq_pulleys.html

 

As Bob say's, just like a flywheel, it doesn't give you more power, just let's the engine rev easier.

 

<pedant mode>
I'm sure Bob means rotating, not reciprocating.
</pedant mode>

The pulleys are much smaller in diameter than the flywheel so weight for weight they have much less rotating inertia than the flywheel.

They look pretty though.