I have released a new version of my web site under /v2/ and now I want a .htaccess rule that redirects everyone from / to /v2/ except if the referrer is /v2/ (because I want to give a visitor of my new site the possibility to visit my old page but noone else). I tried this code but it doesn't work (infinite loop):

Code:
# Checks if the referrer from my new site is being sent
RewriteCond %{HTTP_REFERER}	^http://www\.domain\.tld/v2/ [NC]
# Allows access to my old page and skips the next rule (S=1)
RewriteRule (.*)	http://www\.domain\.tld/	[R,S=1]
# Redirects everyone else from the old to the new site
RewriteRule Redirect / domain\.tld/v2/
How can I get this to work?
Thanks