CAAD10 TT dip?

[GuyGadois]

I noticed a slight dip in the TT of my CAAD10 a couple of weeks ago. Is this normal? Anyone confirm this is on their frame too? I always thought the TT of CAADs were straight with a slight taper, not a dip.

GG

http://farm9.staticflickr.com/8549/8848698410_cb3cc21433_c.jpg

[Louis]

Does the bottom do the same thing? What about the sides of the TT?

[bikinchris]

Years ago, all of their heat treated Aluminum frames had a dip. Some worse than others. Of course, this is a very different bike. Maybe they designed it that way to pay homage to the old frames?

[Chris]

Years ago, all of their heat treated Aluminum frames had a dip. Some worse than others. Of course, this is a very different bike. Maybe they designed it that way to pay homage to the old frames?

I remember that too. Old guy at the shop who didnt sell Cannondale always said..."show me one with a straight tube and I will be surprised"

[mike p]

I've had a couple few caad's and never noticed any bow in the TT but then again I never put a straight edge on them either. If you stand back and look at it without the straight edge is it noticeable? Could it be from sitting on the TT?

Mike

[fatallightning]

It's a byproduct of the hydroforming of the top tube. It significantly flares and changes shape as it meets the seat cluster. If you look from the side, down the length of the tube, you can see where the kink starts. Look where the tube starts from being round to a squished oval.

http://2.bp.blogspot.com/_5YE7GSZGhGE/TJkDdJca7WI/AAAAAAAABn4/7egb15ciUjc/s1600/caad10_4.JPG

[bluesea]

My 54 arcs, not dips.

[JEMM]

does it affect the bike performance wise?

[Louis]

does it affect the bike performance wise?

I'm sure it does.

Given that a straight line is the shortest distance between two points, that TT is too long. It therefore uses too much material (added weight) and has too much side area (too much drag in a cross-wind). I'd say that over a typical 1 hr moderately hilly ITT course it will cost the rider at least 0.000498 seconds.

[Bruce K]

Pretty sure mine is straight - at least visually it is

BK

[mike p]

Louis, you had me going there for a second!

Mike


I'm sure it does.

Given that a straight line is the shortest distance between two points, that TT is too long. It therefore uses too much material (added weight) and has too much side area (too much drag in a cross-wind). I'd say that over a typical 1 hr moderately hilly ITT course it will cost the rider at least 0.000498 seconds.

[Ardan MacNessa]

Louis, you had me going there for a second!

Mike

I just ran Louis's numbers and ...he's correct.

L = (1/2) d v2 s CL

[dancinkozmo]

..mine dips.
though only about 1/2 as much as yours...never noticed til now

[Ardan MacNessa]

http://2.bp.blogspot.com/_5YE7GSZGhGE/TJkDdJca7WI/AAAAAAAABn4/7egb15ciUjc/s1600/caad10_4.JPG
I really like that flat black colour scheme on the Cannondale, and ...that is a great photo of some of the best qualities of that frame.