I am looking at getting a HRM monitor, but I don't know which ones are good. I have seen some that use the chest strap and then some that have a place that you monitor by placing your finger on it. I can't imagin the latter being to pratical on a bike so is the chest strap what people think is the best option? I am a little tight on money right now so I would like to spend as little as possible on this, but at the same time I want to get something that I know I can count on (I know, I know this is what everyone wants, but any suggestions of specific models would be greatly appreciated. I thank you in advance.