Do you need a tri-specifik bike, if you go to do a tri-race ???
I write this, as this is a big step when most people start on triathlon, and because we will have a full Ironman in Copenhagen next year, Challenge Copenhagen.
I will not tell you yes or no, but let me give an overlook of the things you get, or will miss.
The Frame: a tri-bike normally has som shapes, that makes it more aerodynamic, which on the other hand also adds about 1/2 a kilo.
It also has a more forward angel on the saddelslope (= 76 to 78 degree, against normally 73 on a normal bike).
This gives you the possibility to move more forward – get more aero position – and at the same time NOT to become too closed in the hiparea. Hope you understand.
By not closing your hip, you save your body for the run a bit, and also the strain on your muscles (specially the big gluteus = your behind).
The handelbar: on a tri-bike you will have the possibility to lay on the handelbar, this you can get also for your racebike, by getting some clip-on aerobars.
These are important !!!! Because it saves energy, and because it lets you put your arms together, in front of your body = making your frontal area against the wind much smaller.
The one thing you also get on a tri-bike, is the gear shifting, at the end of the aerobars, where you must open and reach out your arms to shift on your race bike, again taking wind.
The saddle: on a tri-bike, you normally get a saddle, that is soft in the nose. This is good, when you need to lay very low for a long time. Again, this is something that you can just change on your normal bike, and the effect is just as good.
The rest is just add-on I think, works the same for tri or race bike:
wheels, if you can afford, get some Zipp 404 or 808, they are just best in rolling, aero and weight (and they last) and yes, there are many good wheels out there.
Drinking bottle: very popular is the bottle that is mounted between the aerobars, this lets you drink and keep the aeropositon at the same time, very good.
Ceramic beeraings: in the wheels, in the crank and the 2 pullys on you backshifter. It costs, but is just rolling better.
Last i must remember to say, that on a race like Monaco 70.3 and even on Ironman nice, you see many using racebike, because there is so much climbing, and pure downhill riding.
So if a mountain area is the place you go to race, maybe you dont need a second bike, check out the profile of the rute, and good luck.
See you out there, Kaisa.