Originally Posted by genejockey

The answer to this question, like so many others, is 'It depends'. I wouldn't buy a bike just to use on the trainer, but if you have more than one already, you might set one up for it. I've been using one of my steel bikes on the trainer, because in Northern California, winter means wet, and I'd rather not expose 30 year old steel frames to that when I have CF bikes I can ride. And yes, I use both a sweat guard and a towel to keep the perspiration off it.

Another consideration is position. You might be more comfortable on the trainer with a higher bar than you ride on the road, especially if you go for a big saddle to handlebar drop.

Even if you don't have a dedicated bike, you might have a dedicated rear wheel, if you're using a wheel-on trainer. I have an old 32 spoke Ultegra/Open Pro wheel with an old Conti 'Ultra Race' tire that's worn flat in the middle, and a cassette I wasn't using, and I swap this onto the bike I use on the trainer to replace the much better wheel/tire I use on the road.