Tri bike geometry vs road-bike clip-on saddle adjustment

Triathlon Forum
1

Hi everyone,
Was looking for hilly IM race next year (4000 meters elevation) and was thinking to use my road bike and not my tt bike next year (2kg difference, and better on descent).
I will use some clip-on tt extension with it and was wondering about geometry, especially the saddle adjustment forward / backward

On my tt bike, nose of saddle is at 1.5cm behind of bottom bracket, on my road bike i’m actually at 7.5 centimeters.

How much did you think i need to move forward my road bike saddle (or i dont move it and just reduce the read of my pads ?) ? It seems hard to replicate my saddle adjustment and maybe it will not help so much on climb ?

Any feedback appreciated !
Thanks a lot

2

Both! Move the saddle a few centimetres forward, and expect to have aerobars that rest on your forearms rather than near your elbows. Are there switchbacks on the descents? This is where a road bike really shines, regardless of how easy the pros make descending on TT bikes appear.

3

I am doing Nice, will use road bike, fast forward seatpost and clip-ons

the climbs are long enough to warrant it and I won’t be threatening the front of anything

4

There’s no IM race with 4000m of elevation. Where do you want to race?

5

So, I crunched the numbers really quick and if you actually found a race with 4,000 m (13,200 feet) of climbing, those two kilos would save you about 4 min 20 seconds over your trip bike while climbing. Depending how steep the climbs, that could mean between 50-80 kms of climbing. So then you would have 100-130 kms of descending where your TT bike will be faster (unless you don’t feel like your TT bike handles well enough to descend mountains).
As with most applications, unless your road bike is pretty aero, you will easily gain back the time you lose on the climbs when you start going downhill or on the flats.

I once used one of those high tech calculators to show a friend–who was deciding between a lighter bike and an aero bike that the aero bike was actually faster over a climb because it gained back the time on the descent that it lost on the uphill.

My climbing bike has a dual-position seatpost and aerobars because I mostly ride by myself and I obviously have to ride the flat areas between mountains. Aero is so much more important than weight that it does not take that long in the aero position to make up what you lose in extra weight.