Ok what do I need to know about why I would want to look at SRM’s over a powertap? Seems the PT is more accurate unless you have the scientific version. I’m aware you can use any wheel with the SRM’s. I have a rear disc anyway so was looking at using the power just for training and going by feel for racing. What else am I missing. Seems most have PT’s. Is it just the cost?
There’s lots of info on the Internet comparing/contrasting powermeters (http://www.midweekclub.ca/articles/ and http://mywebpage.netscape.com/rechung/wattage/ come to mind).
I think you have the basic idea of trading off cost versus wheel choice versus crank choice. My feeling is that accuracy is less important than reproducability. I also have the feeling that there isn’t a “perfect” powermeter yet. I’ve heard good and bad things about them all (some of which might be true; some false).
My choice was the Ergomo (www.ergomo-usa.com) which replaces the bottom bracket. Overall I’m happy with it and, on balance, it suits my needs better than the other powermeters available. I have no personal experience with SRM or PT.
As for racing, check out Richard Strauss’ article at http://www.cruciblefitness.com/etips/IMPower.htm. If you can, it doesn’t really hurt to race with a power meter.
Rob
I have both. They both have their pluses and minuses. You have to decide for yourself which is more important to you in your situation. There are some situations where the SRM mounts inconveniently, the computer mount is very big, and the crank sensor has to be placed just right which is hard with some carbon frames. The PowerTap forces you to give up the real disk wheel.
I’ve had to send my PowerTap wheels in about once every year or two for service - there’s an internal non user servicable part that wears out. This has been free so far. The SRM requires that the crank and CPU be sent in for service for a few hundred bucks every two or three years. SRM also recommends replacing the crankarms every year, non DuraAce arms cost 200 per pair ( they are hot forged and machined out to lighten them, the arm just screws on the base of the crank on the right.).