As an older rider (56 y.o. and only small framed @ 63 kilo) I am looking for a new bike which will not rattle the bones too much on the commute to work (16k).

My problem is I have a 25 y.o. steel frame road bike (English Raleigh Pro-am 12) and although quite heavy by today's standards, it is reasonably comfortable to ride.

How hard is the ride in these new $A2,500 to $A3,500 aluminium bikes? (e.g. Trek 1500, Trek 2300). Or should I stick to steel?

Mind you, I am determined to have the speed and thrill of a road bike or touring bike rather than a mountain bike, because I also ride in long cycling events (such as the 210k Round-the-bay-in-a-day ride).

Any advice from those that have made the decision before me?

Also, how effective are carbon forks and carbon seatposts to improve the ride? Or would a good gell seat and padded handlebars do a better job?

The bike sellers are trying to get me to have a steel frame made up with Integra gear, but the price is coming up closer to $A5,000 than $A3,000. Is it worth it?

Would appreciate any advice, especially from older riders who know what I mean by thin bones!