Currently on my road bike, I have a Cateye Strada and a Polar HRM watch. That way I have speed, and my HR. I mainly use that bike for spinning. Works fine.

But on my tri bike, I have a Cateye computer on a little plug mount between my tribars, but there is not room to mount anything else. I could wear a HRM watch, but that would be hard to see without constantly flipping my wrist.

I want to try to keep my HR in Z1/Z2 on my upcoming Ironman. So I am looking at buying a new computer with an HRM. I have considered mounting my Garmin Forerunner 305 up there, but for regular use, it would be a pain to have to keep it charged, and taking off, and putting it back on.

A few computers I have been looking at:
Polar CS100b (I already have a Polar HRM strap)
Cateye V3
Garmin Edge 305.

The Polar CS100b is the cheapest at about $72. But some people have reported issues with the speed sensor not working. I am guessing they installed them incorrectly. The buttons are supposed stiff too.

The Cateye V3 I can get for about $123. It had cadence which would be nice. I like the display layout. It has calories, but supposedly the number is screwey.

The Garmin Edge 305 appears to be a bike version of my Forerunner 305. I can get a refurbished unit for $170. I like my 305. The unit would be easier to put on and take off the bike. But unlike a regular bike computer, I would have to make sure it is charged each ride. I would get data I can DL into the computer which would be cool. But other than an initial look, I don’t do much with it. I have read a bunch of reports of the unit shutting off when people hit bumps. That would not be cool.

The Garmin 705 would be cool, but much more expensive.

I am currently leaning towards the Cateye V3.

I would love to have a full blown power meter, but I can’t afford that.