I work for an online cycle shop who keep all our discontinued product pages online, so that people can see the stats of their old bike, if they ever needed to go back view it again. This causes a problem on search engines because the web pages of the older ‘discontinued’ version of products generally ranks higher than the web pages of the newer versions of the same product, which we have in stock and want to sell.

For instance, lets say someone searches for “Kona Coiler”, our old “Kona Colier 2006” page appears on third on Google organic listing, when we really want the “Kona Coiler 2008” page to appear in its place. We have tried adding the web pages of the discontinued products to the robot.txt file, but the web pages of the newer version of the products haven’t reached the same high ranking positions of its predecessors. We have thought about redirect users clicking on the old pages to the new page of the product, however, this might confuse people.

Does anyone have any suggestions on how we can overcome this problem?

How about adding a 'related products' or 'you might be interested in' tab in a prominant position on the page? I generally use for products that are temporarily out of stock.

Why not put the new content on the old URL, and then install a link to the old content from that page?

JohnW has a great idea and you also might consider leaving up old pages like the 2006 example you included only marking them as sold out. Providing additional resources like product manuals and so on for older products works.

For example, the other day I was looking for a user manual for a year old printer discontinued by the manf. and couldn't find it on their site. I did find it on another site and while there ordered a new printer.

I have to deal with this on a daily basis, but I have a very persistent boss that likes it a "certain" way. For instance, she never wants to lose one iota of traffic for that page, which means a few things in my book.

1.) Don't mess with the page driving the traffic to your site (Assuming you ranked well in the first place)

2.) Remove the buy button or option to purchase and replace with some verbiage or image describing that this is no longer available (To avoid Customer service headaches)

3.) Outdo yourself on the last one with your new replacement.

Typically, we will toss in a large image at the top of the page that will coax them to the new model, after all, it's the sale you want, right? this leaves the actual content 99.9% in tact so you aren't messing with rank. It also converts people and the spiders to the new page.

Of course, all of this assumes that the product will never be sold again. All of the ideas posted above, I think, are great ideas, but I also think it really depends on what your end goal is. You may want to do a 301 redirect to the new page or you may want to rewrite the old page with new info. I guess, the best option (in my humble opinion) would be to create one great page with multiple variants (years) of the same model and you could do both in the same place...

If the product is permanently discontinued, I would 301 redirect it to a replacement product (or something similar). If you will be getting the product back in stock eventually, there is no point in redirecting or removing the page because it will be forced to start over again when you do get it in stock. I would just use a 'temporarily out of stock' button for users and leave the page as it is so that the page still ranks in the SERPs. Whether or not it is in stock matters little to Google. They just want to see that the page is live.