I've been putting in a little time on the bike trainer of late - something I basically despise - but I really need to get some exercise on a daily basis. We made the trainer at the high school several years back from a picture I saw in a book. I don't remember the book but it either had John Howard sitting on it or it was a picture of his personal trainer. The bottom bracket sits on an adjustable support so you can control the amount of weight you put on the rear wheel. The rear wheel turns the axle to drive the squirrel cage blower and there you go. Originally it was outfitted with two blowers but even in the lowest gear it was more resistance than I needed. Like many of the contraptions the boys and I have built at the schools, this one was put together from scrapped or salvaged materials so the cost was pretty much next to nothing. If you have a really sharp eye you'll notice the color is the same as the English wheel I posted previously - didn't even have to buy a can of paint. I've got this one set up so it works pretty well now but I wouldn't recommend trying to make one. It's kind of fussy trying to get the tension right and it's a little tough getting on and off the thing due to the height.
The bike is a cheapie road bike like those that were everywhere back in the 80's. It has a Brooks saddle but in name only. Like most of the cheap saddles it's uncomfortable as hell - no wonder people who bought these bikes never rode them. I've got a new Brooks B17 that I'm going to throw on the bike so I can actually stay on the thing for more than a few minutes at a time and turn the handlebars back down like they should be. I turned them around when I was having all that trouble with my chest so I could sit up straighter. I should be able to manage spinning for awhile with my hands on the hoods or in the drops now.