We have talked about URL length issues and SEO and if long URLs are spammy in the past. But now we have a Google Groups thread with a Googler, JounMu, actually commented on a specific URL as being a bit too long for comfort.
The example URL in question is:
http://www.gadgetguy.com.au/small-kitchen-appliances-toaster-kettle-coffee-machine-blender-juicer-channel7-sunrise-australia-42.html
John said "Now I'm all for having descriptive URLs, but .... this seems to be taking it a bit too far and I have a bit of trouble identifying anything that matches in the content of your page." Too far? Does that mean Google will penalize really long URLs? Or in this case, it just looks spammy to a manual review?
Digging in deeper, John noticed that you can find the same page as long as you include 42 at the end of the URL. Now, this is a common CMS issue with many sites. What should be done in this case, is a 301 redirect from the broken URL to the true URL.
I assume in this case, the CMS identifies the page by having the ID (i.e. 42) in the URL and then returns the dynamic content. The CMS should contain a real URL and then 301 redirect any other URLs that have id 42 in them to the real URL.
So, when building a CMS, you might want to do a couple things in terms of URLs:
(1) Restrict the length of the URL to something normal (2) 301 Redirect any duplicate URLs to the real URL
Now, I may have stretched John's words here but it does seem that he is pointing out the URL as being something that may raise a red flag in Google.
Forum discussion at Google Groups.