Weight distribution on tri bike

Technical

2 messages
29/04/2018 at 12:26
Hi everyone, quick question for you all. I have just set up some clip on aero bars and changed the seat post to a profile design fast forward to assist with getting in an aero position, but I feel like a LOT of weight is now in the bars, where before most of my weight was on the saddle. Is this normal for a tri bike? I only have it set up on the turbo trainer at the minute, and am worried about the affect in the handling with all the weight over the front wheel. Advice greatly appreciated!
30/04/2018 at 10:58
Damon, sounds like you've gone too aero. Your arms should simply rest on the bars rather than support weight.

Apart from handling this is a significant issue relating to performance. The more weight going through your bars means more work for the postural muscles located above your hips to hold that position stable. Your body will always prioritise stability. This means blood is diverted away from the working muscles below your hips. Reduce your above hips work on the bike to breathing and pumping blood. Oh, and steering, changing gear etc.

These hard working postural muscles may well compromise your ability to breath as freely as you would like. Again reducing performance.

You may be crunching your hips so cycling with shortened hip flexors and none/under functioning glutes and hamstrings. This is you will find out when you get onto the run.

The position you describe may not be sustainable. How long can you hold it without having to move and so loose that aero position? Sprint (+30min), Standard (+60min), Ironman (all day apparently).

A good aero position is one where the above compromises are outweighed by the aero gains. That calculation must also take into account the effect on the run split. Consider doing some longish repeatable race pace reps on a quiet and flatish road trying different seat positions each time. Record times, power (if you have), heart rates and how you felt. The optimum position should become obvious.

Reducing the frontal area is not just about going lower. Think about being as narrow as is safe by bringing in the arm rests to the centre. Look to use your hands and arms to divert the airflow around your body. This may require some flexibility work. Also consider using the tortoise position for your head rather than keeping the neck neutral.

Hope this helps
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