New folder structure

[AlanMosley]

"A 301 will pass 80% of the page authority over."

No a 301 will pass 85% of its incomming link juice, you are redireceting the inomming links not the page

A 301, passes 85% of its PR from the page to another page though a link from the page.
But if the page no longer exists it can not. Once you delete that page, it no longer has any page rank, but the pages that may link to the old page are still passing PR, so in that case you can redirect those links to the new page. But you cannot redirect the non existing page or any authority it had to the new page.
Read Google’s algorithm, I assure that is not how it works.
http://www.webworkshop.net/pagerank.html
By the way, all links pass 85% of link juice it has though its links, if the link hits a 301 redirect, it loses 15% again. This is so you don’t get infinite loops.
Imagine if you could move a page and somehow gets its PR by doing a 301 redirect. You could keep moving it and it would keep getting more PR.
If I could use an analogy
If you have a store and Bob has a store, and Bob closes down, but puts a sign on his door telling his customers to go to your store, you will get his customers, but you don’t get his stock. And if he had no customers you get nothing.
Anyhow if you read the link you will see that I am correct

[ASOS]

Ooops, should have said link juice.

As you can all see Alan and I have different views on this but at least you have a range of views Tommo!

Good luck - hope it all goes well.

[AlanMosley]

either way, it would not hurt to 301 all.

[NeilTompkins]

Hi ASR, can you advise more on how you moved to the new folder structure ?  Did you leave old pages in place, launch new site, then go through all old URLs and 301 them to the new URL ?

The problem I have is the new folder structure is not a standard pattern, so any 301 will need to be done manually.

[ASOS]

Hi Neil.

The sites we have done are all new but from experience dealing with moving to new urls the best thing to do is create a mapping document in excel. It'squite easy if you know that for example:

www.domain.com/berlin-hotel is moving to www.domain.com/de/berlin-hotel.

Then all you need to do is put in the 301s based on the mapping and monitor WMT for issues - you will always miss something.

From what you are saying however there is no logical structure to your site - which will make this harder. I have had to deal with this in the past too, you might just need to identify all of the more important pages and 301 these first and go via mechanical turk of get an intern in or something to just plough away and find all of your urls.

If you have an XML sitemap you should be able to get them all pretty quickly and map from here.

Hope this helps.