I'm putting 17mm hex adapters onto my Slash 4x4 should I change the gearing??
Is it advisable to change the gearing once I start using 1/8 buggy wheels? I am running stock at the moment with the Stock Velineon?
You should be fine running stock gearing. I have had no problems in the past.
Buggy wheels are pretty much the same size as SC wheels, in most cases.
I run them without issues, stock gearing.
You shouldnt have a problem with gearing, but that depends on the tires you get. If they are a lot larger in diamiter, it will affect your speed and the strain on the motor slightly since they have a larger rollout value. however, MOST buggy tires are pretty close to the same size of the SC tires so you shouldnt run into any problems heat wise just by switching them out