Fit Gurus: Zipp Vuka Cockpit Fitting Challenges for Tall TP'ers
 

So...I've got the Zipp Vuka cockpit and am having trouble figuring out how to bring my hands into a more beneficial position for aero. I've got the bike measured up for the UCI jig nearly spot-on, and if I tilt the extensions up, I'll get outside of the 10cm vertical limit from center of armrests to top of aero extensions, so that won't work...Unless I figure out a way to get my armrests closer to the hands and move the contact point from elbow to forearm. And, in order to do this, I'd have to find spacers for underneath the armrests only...so they can stay within the 10cm vertical limit from tops of the extensions....and then I'm wondering how much better/higher the hand position will be, and if the aero benefit (if it's let's say, a couple of centimeters higher) outweighs the increase in stress in the arms and inefficiency that may result...

And, yes, I made the foolish error of buying the Zipp spacers, which I didn't realize raise both the armrests and the extensions together, accomplishing nothing productive (unless I chop off a couple of inches from my upper arms, which I may consider). I didn't add the spacers to the cockpit after realizing what a ding-dong I am, I should've looked more closely at the setup before thinking those would help. :D

This is a fun puzzle. I think. :)

I have a Vuka Evo 110 extensions with a Vuka base bar with this clip/armrest setup (above bar):
https://zipp.com/bars/vuka-clip/

And for current position, here is a recent side photo without aero helmet on, nor aero wheels on the bike:
https://cimg5.ibsrv.net/gimg/bikefor...cf759c004f.jpg

Loaded questions in here... I'll try to break it down

First the question of it being aero. The answer is... maybe. I've looked at a good number of guys lately who have jumped on the HUUB Wattbike train... and after some field testing, for most of them it's worse. Angling the arms is very hit or miss (you can read back 10-15 years John Cobb did a lot of testing mantis positions) the angle usually needs to be "right." What is right? No way to know but test... I have seen massive differences between a couple of degrees though. Also, in general (not always) going "mantis" is better at low yaw and worse at yaw. Inside a velodrome, that's usually a net positive as the angles are always very low. Outside, it can be pretty windy on the track. I say all that but at the end of the day... I can only tell you it can be a good amount faster, but when it's bad, it's often VERY bad. I would say the best "eyeball" judge is to see if it drops your shoulders (narrows them) and your head. At the end of the day for all aero fit, that's almost always the thing that will help. If your head pops up, it's no good. (again, broad strokes, not always)

As for the technical side of the question... you can raise just the pads with any spacers (so long as the bottom/top is flat - 3T spacers have little nibs on the bottom of them you'd have to grind off) ebay usually has some no-name carbon ones (search aero risers or aero stack spacers) or the old vision ones (they should work) In a pinch, you could just buy some aluminum pipe a little bigger than the bolt and cut it to size and use it to space it out(basically what the new Giant TT bikes use) Angling the pads will net you a small amount of room as well

Position overall - I'd move the saddle back a bit. Maybe a 10mm spacer under the stem.

Thank you, very much appreciate your feedback. I'll track down some spacers, looking for those you mentioned.

I believe there really is no way (for me with my long spider monkey arms) to get hands up very much, so it will be interesting to see if a small change makes any noticeable difference. And, if there is an aero difference, I'm wondering if the more forward armrest position (needed to keep pads within UCI vertical distance from extension tip/top), with cups under forearms instead of elbows, will engage arms, wasting energy, and the net will be zero. I'm skeptical.