After trying moving the Alt bearing in its adjuster, and the old boat anchor solution to adding weight to the back of my 12" GSO dob (I wasn't happy with what the chain was doing to the base), I opted to try the Farpoint counterweights (which they make for the Lightbridge 12"). The newer GSOs come with three additional holes in the rear mirror mount ring that are tapped for M8 bolts, and are not used for anything else (all the Spring knobs and push or locking knobs already have holes, so nothing needs to be changed to use these countweights. The Lightbridge kit comes with three counterweights and three 6mm cap screws, the weights are therefore drilled for 6mm bolts. To use them on the GSO, just run a 8mm drill bit through the weight hole to open them up for 8mm bolts. You'll need three 8mm bolts at least 50mm long to secure the weights to the ring. The weights do not foul against anything when the dob is vertical. Looks much better than that boat chain, and no noise.
This is what they look like:
http://www.farpointastro.com/lightbridge.php
I got mine from Bintel here in Oz. Yes I know they are more expensive than boat chain but it's a nicer solution, and you can just put on as many as you need for your setup.
Finally, ignore the instructions that come with the kit as you don't need to replace the push knobs or upgrade springs and knobs etc to put them on a GSO dob. Just make sure you check your particular GSO dob to check on the holes and thread before you start as I kow the older ones maybe different (as might the smaller or larger sizes).
