BigGear

I am 44, 160lbs. When I ride at 80% of my HR max, my power output is only 155 - 165 watts.

I guess it is low...

I wonder what other people of my age average at this HR percentage..

I did this test on a powemeter (CycloOps Electronics), on a road this HR gives me
15 - 16 mp/h

If riding 40km time trial at or near LT I can average 19 mp/h

I would guess switching to a road bike (I ride Trek 7.5FX hybrid) maybe give me something,
but I am not sure how much..

CdCf

Well, I'm 27 and you're way ahead of me. Over 40 km, I think I could only just average 17.5.

DannoXYZ 

That's pretty darn good really. Why 80% though? You might want to do the 2x20 AT test stickied above to determine your LT/VO2-max balancing point. That's where you'll make maximum continuous power. I suspect you'll be able to crank out a couple more extra watts for sure. Good job!

What you'll find with training is your muscles get more efficient; they'll be able to make more power for the same amount of oxygen consumed. So you'll find that VO2-max won't increase that much and your AT-HR won't increase very much, if at all. BUT, the power-generated at AT will increase tremendously, +25-50% isn't uncommon.

BigGear

It certainly does not feel that way .. In the last triathlon I averaged 18.9 mp/h and in the overall bike leg this was 76 out of 108 people. I would say the middle pack average 20-21 mph on 40km.

I am just wondering about people passing me..

Do I need a better bike or it is just traing?

DannoXYZ 

It's all in the training really, bike is worth maybe 1-2mph max. Actually less than that when I compared my road-bike vs. MTB on a recent 10-mile TT. Although once you put slicks, aero-bars and a straight-block on an MTB, it's pretty darn close to a road-bike. But a road-bike will allow you to train for more hours with more comfort in the long-run from having multiple hand-positions.

I went from 19mph in 40km-TTs to 24mph in less than a year with lots of optimized trainig. Getting above 25mph took another year. There are sacrifices however if you specialize in just one event. My sprints and hillclimbs suffered if I focused on just TT performance.

BigGear

That's what I thought too.. Why spent money on a new bike?

What's bad with hybrid (and mountain bike too) is upright position. It is really bad if there is headwind

Thank you very much for the thoughts

VosBike

So, at 80% of MHR you are putting out 2.2 w/kg.

If you are well trained, your LT HR is probably quite a bit higher, and that number could rise to 3.0 w/kg. That is quite good and puts you around the middle of the cat 4 pack (power wise).

Keep training and those numbers will keep going up. Much luck