Changing url patterns (many pages involved)

Hello All,

Having to change the URL patterns of my 20k pages already indexed by Google, would the setup below be the optimal way of doing things? Will I lose some Google traffic initially when I implement the changes (most of the current URLs have a non-zero PR)?

Thanks!
James

Current setup:

www.example.org/articlelist and www.example.org/articlelist/id/<articleid>
RewriteRule ^articlelist$ /view-articles.php?id=all [L,NC]
RewriteRule ^articlelist/id/([0-9]+)$ /view-articles.php?id=$1[L,NC]

Proposed setup:

www.example.org/articles and www.example.org/articles/<articleid>/Learn-About-Blue-Widgets
RewriteRule ^articlelist$ /articles[R=301,PT]
RewriteRule ^articles$ /view-articles.php?id=all [L,NC]

RewriteRule ^articlelist/id/([0-9]+)$ /articles/$1 [R=301,PT]
RewriteRule ^articles/([0-9]+) /view-articles.php?id=$1 [L,NC]

 

I think doing a 301 redirect from the old URLs to the new ones will make Google update its listings. Or you can make both old URLs and new URLs work and change the links to the new URLs and once Google updates the listings to show the new URLs, delete the mod_rewrite code for the old URLs.

 

If the content is identical Google could penalise you for having both sets.

 

Thanks for the feedback guys

blacknight, I am afraid of the same as well. I described the problem in more detail in the SEO->Google forum. Hope to get some feedback or hear alternatives on that as well. http://forums.digitalpoint.com/showthread.php?t=23168