Originally Posted by fettsvenska

I believe that this is true which is why the road racers are always looking for the most rigid frame possible so that all of their pedaling energy goes into moving them forward. However, I don't know how significant or marginal that loss of energy is.

I'm not opposed to suspension (either front or rear) and I believe it has its place in cycling but I believe that there are many (maybe even most) cyclists who purchase suspension when they don't actually need it. I think that the terrain needs to be pretty rough and/or technical to warrant suspension. IMO there are 2 other disadvantages to suspension that are more significant than the loss in energy:

1. Cost. These days it seems like a suspension for of reasonable quality is going to cost at least $800 and maybe even more. So if you factor that into the cost of a complete bicycle, you're going to shell out quite a bit for your bike.
2. Maintenance. This is one of the reasons why I got rid of my full suspension mountain bike and now ride a rigid frame. It seemed like I was getting my suspension serviced at least once per year and sometimes more. The bike shops in my area are all always backed up at least 3 weeks and sometimes even longer. So if I had to get my suspension serviced twice a year, my bike would be sitting idle at the shop for a total of 6 to 8 weeks. This was a bitter pill to swallow for a bike that cost me $2,600 back in 2011.

Obviously just my opinion but after having owned both a full suspension mountain bike and a rigid frame mountain bike, I prefer the lower cost and lower maintenance of my rigid frame. Again, I'm not against suspension and if you already have a bike with suspension, you should keep riding it but I just think that suspension is over-sold by the bike industry.