I'm trying to get an idea of how much i can improve when i get my own bike (i plan on buying one soon). I've down a couple of sprint tri's on a borrowed cannondale road bike, it's old and has no areobars, but is a good bike. for the competionions I averaged just over 19mph, and most of my training rides are in the mid to high 18 mph range. So my quesiton is, how much faster could i go with a good new bike, and what do i need to make sure i get with it? are areobars and clip-in pedal essential, or just a personal choice thing? and how much of a difference will I feel with a bike that is fitted for me? how much time can i drop over a standard distance tri race? thanks for any help.
your own bike will feel like a warm apple pie
Well if you get a bike that fits you like a glove then there will be a big benefit, fit is the most important part of buying a bike. Clip on aerobars and clipin pedals would make a huge difference especially the pedals. Its really hard to say how much time you will gain but you should notice a difference.
How comfortable are you on the road bike? If you feel you have the handling down (it sounds like it if you are racing at 19 MPH), you might consider a triathlon bike, you'll notice an improvement based on the aerodynamics and newer equipment. I rode on a borrowed bike for a year or two and then went directly to a tri bike.
On a new bike you can probably expect SLIGHT improvement
(this assumes that the bike you have is functioning properly and fits you)
Just read Lance Armstrong's book - [I]It's NOT the Bike[/I]
Your fitness is the main the factor in determining how fast you'll go. However, there is a slight advantage when considering the aerodynamics of a bike. For example, I've noticed the ability to gain on other riders on down hill segments. I ride a P3, even on 650s and freewheeling, the bike will gain on most tri frames. That means on a flat portion you'll save on output cutting wind resistance. Proper bike fit is critical to benefit from aero advantages. But don't expect to jump to a 22-23 mph avg. by just switching to a tri-bike.
Aero position will make the biggest difference. Aerobars should be worth 1-2mph, or 2-3 minutes in a 40k (of course this depends on how aero you are now on the road bike and how aero you'll be on your new bike) Next biggest difference is wheels. Disc rear wheel, and a trispoke front wheel is worth about 1/2 to 1 mph, or a minute or so over 40k. A moderately aero, low spoke count wheel, compared to the 36 spoke wheels you probably have on your cannondale is worth a fraction of the above, maybe 30 seconds on a 40 k.
Aero time trial bike frame. Harder to quantify. The Aerodynamic drag of the bike itself might make a 30 second difference in a 40 k, due to more aero forks, aero tubes, internal cable routing etc. but the biggest difference is the TT frame will allow you to get in a good aero position easier, thus getting back to the the 1-2 mph alluded to above from the more aero position with aero bars.
I'm a relative newbie so my advice can be taken with a grain of salt. I have a roda bike, no modifications to it except for the clipless pedals. I live in a relatively hilly area and was riding with sneakers and the regular strappy foot pedals (sorry, i'm at work and that is my technical terminology. :D). Anyway, I have been able to notice a difference in my efficiency since adding the clipless pedals and a cheap pair of bike shoes that fit me correctly. I don't know what it has given me as far as speed gains or energy savings while riding but it doesn't feel like i have the same amount of struggle.
Here are some links to find out more about the benefits of clipless pedals.
[url]http://www.trifuel.com/forums/showthread.php?t=802[/url]
[url]http://www.trifuel.com/forums/showthread.php?t=526[/url]
[url]http://www.active.com/story.cfm?story_id=12309&category=Cycling&num=2[/url]
[url]http://outside.away.com/outside/gear/gearguy/200412/20041227.html[/url]
Good luck.
Getting your own bike will make a big difference.
Whether a road bike converted for Tri's or a Tri specific bike - either way you should see an improvement.
Simply for getting a bike that is fitted properly to you is the number one benefit - With a good comfortable fit - should have increased power and endurance.
Then with all the extras, areobars, pedals, etc. you can continue to increase your performance.