Low Back Pain/Shorter Cockpit (Rappstar Tweet)

Triathlon Forum
1

I saw this exchange on Rappstar’s twitter feed and was a bit confused.

@rappstar if u were to lower your front end 2cm, would u be taking pressure off the lower back by being less upright? Impossible to answer?

@slowswimmer In theory, primary way to alleviate low back pressure is SHORTER cockpit, which lower front SORT OF does (among other things)

I thought lowering your front end would lead to a longer cockpit due to the angle of the steerer tube. What am I missing here?

And how would be less upright take pressure of the lower back? Wouldn’t it increase the pressure?

2

Wouldn’t lowering the cockpit put more weight on the front end since you are shifting more weight towards the front of the bike?

3

Wouldn’t lowering the cockpit put more weight on the front end since you are shifting more weight towards the front of the bike?

I think yes, it would put more weight on the front, but might also take some of that “weight bearing” off the lower back in the process.

4

If you only move your bars down in the Y-plane, then as you lower your bars, your back gets flatter, which means your back gets “longer.”

On most bikes, lower the bars by removing spacers also lengthens the cockpit, so it probably stays neutral as your back gets flatter and “longer.” But on many newer bikes you can lower your cockpit without making it longer (by design; such as on the Shiv). And, on any bike, you can lower your cockpit without making it longer depending on how you get lower.

Like, if you have Vision aerobars with 2.5cm spacers under the pads, and you take those pads out, then you only have gone down, not out.

Make sense?

5

Makes sense, I was thinking of sliding a stem dow,n a steerer tube, not removing aerobar spacers.

However, I don’t understand how removing spacers keeps it the same with regards to the difference between flatter and longer. If I remove a spacer or two on my Roubaix I think I am lower and longer. But you are saying the length is neutralized by the flatness of being lower?

6

But you are saying the length is neutralized by the flatness of being lower?

Correct.