Thats where the problem lies, if a specific structure is given and copied then that structure will become ineffective as well. Some things are better shared as concepts and then left for the individuals to work out the specifics.
Linkwheel is just a good term to use to describe a type of artificially interlinked system. Search the downloads section for an ebook called linkwheelexplained.pdf download it and read it. That explains the original linkwheel concept and the original spoked wheel closed link structure. Get an understanding of how the interlinking is funneling the most amount of pr to the hub site.
Once you have that understanding, map out your own structure. Make it an open link structure, simulate more randomness that a simple spoked wheel, and use the math to make the interlinking funnel as much as pr as possible to the hub site.
Even better than linking to your main site, your should create silo sites. Create several sites that are real sites that are not linked together at all, create original content relevant to your main site, basically jsut a few minisites that compliment your main site. They need to be on there own domains and preferably seperate ip.
Do your standard whitehat link building for each silo. Then create a seperate link wheel for each silo. Each of the linkwheels should be mapped out with a different structure. The idea is to create your own mini authority sites. Then each of those sites will link to your main site. While doing all of that also do regular whitehat seo backlinking to your main site so everything looks really natural. The regular backlinking, combined with your 4 or 5 silo backlinks, should give your main site some authority and really help move it up in the serps.
The concept is still great, you just can't copy each others linkwheel structures anymore. I think there are a few linkwheel services in the bst threads that are considered effective. I haven't checked them myself so I don't know for sure. I imagine if they are still selling the service they've adjusted their linking structures to stay effective. You'll need to ask them yourself before deciding to outsource it. It will be pretty difficult to do it right yourself if you don't have a pretty good understanding of the concept.
Thats the concept and the theory anyway. Now you have to map the specific structure yourself. The days of sharing a linkwheel structure are gone. Thats why you hear so many people saying linkwheels are dead.
Good luck :beerchug:
edit- Linkwheels are for advanced seo only. You don't want to start with them. If you make a mistake you can do more harm than good. If natural backlinking were happening to a site, the authority sites would be the later sites that would be linked to anyway. Start with the simple stuff like bookmarking and profile links, then move on to directory submissions, then on to article sites and blog submissions, and then start thinking about link wheels and link silos. That's much closer to how link growth would happen with a real site going viral on it's own. That's the kind of thing you're trying to simulate, you want the SE to think your site is truly getting popular on its own merit. If you succeed then you end up at the top of the SERP.
If you need a primer on basic seo, go read this thread. You want to be doing all the basic seo suggestions before you start using more advanced tactics.