right i might be being a rit nood, but want to fit a power disc set up, to my redline crank arms , the redline chain ring has a little extra hole where the crank arm fits nicely instide the chainring, but on the power disc it sits outside the hole, trying to explain, or do i need a different power disc, cheers
![](http://www.radbmx.co.uk/archive/albums/aa143/bmx1973/DSCF0475.jpg)