I agree. It does sound as though 180 is pretty close to roadie chick's max HR. But roadiechick, the thing for you to understand is that if you put in a block of base training - lots of kms in your E1 (65-75% of MHR), this will often make you able afterwards (say, in a few months time) to go on the same rides and do the same pace while working at a lower heart rate. This means that because your body is doing less work for the same results you should be able to maintain that pace for a longer period of time.

IMPORTANT - this is only what worked for me. The training that you need right now MAY be different. I did this over summer and it worked wonders for me, I am a stronger rider than ever before.

I advise talking to lots of other riders about it, but the problem with this is everyone has different ways of doing things, so you'll probably get 5 or 6 different answers and it can be confusing.