I am thinking about getting the Zwift ride. But, I need the handlebars set pretty high due to neck arthritis issues. Does the default setup allow the bars to be cranked way up or will I need to add spacers (and can you even add spacers)
based on the specs, they can be raised about 8 inches
The relative height of the bars compared to the saddle will depend on how far the seat post is raised. A relatively short rider will find the bars can be raised to a very high height. A tall rider, not so much. Adding spacers is not an option but the stem has considerable height adjustment built in.
There are also third party handlebars that have additional built-in rise but installing them is a bit of work so it may be something you prefer to have a bike shop do for you if you don’t fancy that effort. There is a GPLama video on YouTube that offers a guide to handlebar replacement.