Gramlight 57DR Hub bore
 

I wanted to know what is the hub bore oh the Gramlight 57DR. I wanted to order some hub centric ring.

I've search on the net and found some saying the hub bore for those wheels are 73.1mm and some others says it is 65mm... Wich one is the real size?

Hub bore isn't determined by wheel model. It's determined by who ordered it and requested the hub bore diameter.

Best bet is to get the wheels first, measure the hub bore diameter of the wheel, then the hub bore diameter of the...hub... then order the right size ring. Or take a risk and mount the wheels without the ring since the wheels will self-center with the lug nuts anyways.

^ This

for what it's worth, my 57DR's are 73.1 and i got aluminum hubcentric rings from mackin.

Mine are 65, I would just measure...