Upgrade to Tri TT bike for first IM?

Don't get it because of that.

A TT bike may allow you to ride more aerodynamically.  If you can do so comfortably, then you will be faster.  If it doesn't allow you to do so (or you can't comfortably hold the position that it does allow), then it holds no special advantage over you current bike.  Most people (properly fit) can comfortably achieve better aerodynamics on the tri bike.

Not sure what you mean by "LT benefits of TT bike". Contrary to a commonly held belief, tri bikes are not designed to use different muscles or help you run better off the bike. Their design is all about maintaining a powerful and comfortable cycling position while also making the rider more aerodynamic.

If you want to go faster on the bike and can afford a tri bike, then go for it, but don't expect it to make you a better runner.

Thanks guys. LT = long term... I got caught up in my work abbrevs.

Heh...around here LT means Lactate Threshold, hence the confusion!

i've a lot to learn!

This user's post has been ignored.

Edited by newyorkfan21 2010-09-01 8:19 PM

x2

If the run is easier it's because:

a) you used less effort for the same speed
b) effort was the same but you were on the bike for a shorter period
c) you fit your tri bike better
d) placebo/mental effect

Tri bikes use the same leg muscles as road bikes. For the same effort and duration, your muscles will be equally tired.

I fully agree that the TT bike will be faster, but don't buy that the run is "easier".

I feel the need to chime in on this topic as I have just recently made the switch to a tri bike from a road bike. I can't argue about the leg muscles used as I agree they are the same betwen road or TT. The biggest difference that I noticed was in my lower back and hips. I suspect that this has to do with the muscles of the upper body supporting the weight of the torso on a road bike where a TT bike you have the aero bars supporting the torso via the skeletal structure. I find running off the tri bike to be easier as my lower back and hips are not as fatigued. So now the question is can you get the same benefit with aero bars on a road bike. I think you can, however this set up makes a road bike a little squirrely from a handling perspective. I am faster on my TT bike now, but I can't say for sure that it is the bike as I have been working pretty hard at riding faster so it could be a function of better fitness. 

Kevin