Seat to aero bar drop

Triathlon Forum
1

I was reading Dan’s article on the Cervelo site about tri bike setup.

In it he gives a formula for calculating the desired drop from top of seat to aero bar pads.

For a seat height of 78cm (BB to ctr of top of seat) the drop works out to 14.8cm with a variance of 1.5cm up or down.

This seems really aggressive. Anyone riding with this much drop? If so how many IM’s have you done this low and how did the back, digestion etc work out.

2

Don’t forget that formula applies to steep bikes. It gets less with shallower angle bikes.

3

As Nickc said, I believe the original formula was for riding at a steep 80-degrees. Dan’s webpage offers a variance in the formula for those riding slacker angles (scroll down a bit):

http://www.slowtwitch.com/mainheadings/techctr/bikefit.html

This webpage will help you determine the angle you actually ride at:

http://www.slowtwitch.com/mainheadings/techctr/anglefinder.html

Keith

5

The drop I calculated was for a setup of 78.

This drop would be fairly aggressive for any cyclist including a roadie doing TT’s. They may go a few cm lower but don’t have to run afterwards or TT for 180km’s.

7

I’m riding with at least a 17cm drop. if anything it’s more than that now. I’m out of slowman’s stated zone. I ride at 81+ and am 5’11.

if you work at it slowly you can get there. granted I don’t have a power meter so I don’t know if I should be riding that aggressive or not.

8

I am about 5’10" and ride steep at about 81 degrees. My BB-saddle dimension is 71cm, so Dan’s formula give me a suggested drop of 9.5cm (plus or minus 1.5cm). I actually ride with a drop of 16cm. Seems to me that Dan’s formula is not that aggressive. I am with Francois on this one.

9

I was reading Dan’s article on the Cervelo site about tri bike setup.

In it he gives a formula for calculating the desired drop from top of seat to aero bar pads.

For a seat height of 78cm (BB to ctr of top of seat) the drop works out to 14.8cm with a variance of 1.5cm up or down.

This seems really aggressive. Anyone riding with this much drop? If so how many IM’s have you done this low and how did the back, digestion etc work out.
Andy, I think if you do your numbers again, 78cm will give you a suggested drop of 13.3cm (you appear to have not subtracted the 1.5cm) - Bill

10

My bike is 80 degrees, saddle at 80.5cm over bb. My drop is 17cm for long-distance riding, and 20cm for TTs, Olys or sprints. The reason I raise it for longer rides is that my neck gets too damned sore looking up at the road.