Hi Guys

Not an ideal situation to be in but due to a client having issues with a CMS they're using for their main domain, they're having to use a subdomain approach to house content so they can more readily update it.

I've made it clear this is not ideal and so we're going to 301 redirect key pages to the subdomain but also have a core overview page on the main domain so that we can get some links to the new site and benefit from the domain authority of the main site.

My question is - as these are 301s going to a subdomain that has no history and therefore no authority, how at risk are we of dropping considerable rankings? i.e. I know 301s don't retain all the value of the existing page's rank and that coupled with it driving to a site with zero authority....my concern is it will drop off a cliff.

Any thoughts welcome!