This is a question for those who use Shimano bar end shifters on their aero bars. Did you mount the shifters with the shift cable on the top or the bottom of your aerobar? Why?
Thanks. David K
First a disclaimer – I haven’t done this yet, so I kind of have the same question, but as I’m just getting this (old, but newly a TT) bike set up, I’m going to experiment both ways. Years ago I used many, many set-ups, some of which utilized bar-end shifters. Don’t remember what I settled on then…
Just mentally going though it, it would depend on your style of how you grip your bars. If, like me, you tend to grip them hard and pull, you’d want the cable on the top so as not to irritate your fingers. If you keep your grip loose, I would think you’d want it on the bottom. Of course there’s always the option of running it INSIDE the bar… Of course all warranties would be void…
I like the cable on the top so you pull back to drop into a faster gear. I just like it set up this way better and have gotten used to it. I also have an easier time pushing the shifter forward to get to an easier gear than if I had the lever flipped and had to pull it back to get to an easier gear, as downshifting requires the most force as you are fighting the derailler spring.
I go the opposite. I have it so I push down to get in a smaller tooth gear. That way I can just keep my thumbs on the edge of the shifters and push as I pick up the pace.
The other way they look funny sticking up I think. Not as aero?
Of course there’s always the option of running it INSIDE the bar… Of course all warranties would be void…
Syntace C2 bars have a textured finish and I like that better than the feel of bar tape and cable. Thus I run the cables internally and leave the aero bars bare. It also makes for a much cleaner look. Not many people share my preference, though.
AFAIK, that doesn’t void any warranties. The shifters are made to accomodate internal or external cable use. The internal installation is a little trickier and indexed shifting won’t work. Neither Shimano or Syntace says anything about this voiding the warranty.
Profile is not drilled, as far as I know, to accept an internal routing. So to drill for said cable, it would void any warranty. I should have been more clear on that.
My cable is on the bottom of the aero-bar. I have set my shifter up this way for at least six years and it would be hard to change now. The cable bulge fits into the bend of my fingers when gripping the bar (sort of). I like pushing down with my thumb to get a higher gear.
Some Profile bars are drilled for internal cable routing, I know both my Split Seconds and Carbon Strykes are drilled.
If you mount the shifters with the cable running on the bottom/outside of the shift lever, you may see increased stress and fraying on the cables, especially for the front derailleur. I personally find it more comfortable with the levers curved toward me and the cable running underneath/outside. The curve of the shifters fits my thumbs better, but the trade-off is that I have to replace the front derailleur cable at least once a season.
If you run the cables underneath, be sure to examine at least once a week for any fraying. You’ll also notice some sloppy or missed shifting if the fraying is getting bad and you haven’t been paying attention to it.
Reminds me of a century I once did after the front derailleur cable snapped in half and changed my bike from a 16 speed to an 8 speed with 85 miles left to go in the thigh crushing big gear. Not a wise idea to be riding a hilly century into New Hampshire that day.
BrokenSpoke
Cable on top, push forward for bigger ring/cog. This is opposite of DT shifters on a road bike but it doesn’t mess me up - well OK maybe it did once 
The cables seem to loop around the base bar better when routed on top. I may switch the next time I retape the bars.