What will drilling 2 holes on a pair of bullhorns do?
 

http://img132.imageshack.us/img132/1710/1234d.png
(*just a random picture, not my bike~)

Got a time trial lever~ want to be minimalist and have the luxury of not having to feel the cable under the bar tape, thinking of drilling one hole near the horn, and one near the stem area to guide the brake cable through.

How bad will this be for the bars? (structurally~ ;D)

You can find some old bars that have this drilling.

http://www.fiataccompli.com/bike/pho...le_routing.JPG

http://www.raydobbins.com/ebay/bike-masi/Photo_06.jpg


I wouldn't do it myself. You need a somewhat large oval hole for the cable to pass through and cutting a tube/bar designed to be solid is almost always a bad idea.

By drilling a hole near the stem you'd be creating a weak point at the area of the bar that comes under greatest stress and is most likely to break. I'd sooner find a set of bars meant to accomodate the cable internally than do something like this, but that's just me

some bullhorns have holes pre-drilled in them. profile airwing comes into mind?

I can't imagine a small hole causing a metal bar to fold under pressure. I bet it'd be fine.

i have the profile airwing and it's GREAT for this. The cable goes through the horns and then in a cutout on the back of the bars. Works great. Also, if you're looking for cheap, the Ben's Cycle Tranz-x horns have a indenture on the inside of the curve.

A scratch can cause a bar to fail... just some food for thought.

An oval hole for a cable is not "small".

cable under bar wrap is barely noticeable, if at all, when done correctly.

pulling cable and housing through holes in tubing is always a PITA.

dont bother.

...and, yes, it would be a bad idea to drill holes for a non-aero lever like your picture demonstrates. think about it.

alright thanks for the help guys i think i know what to do! ;D

cheers on getting a functional brake. :D

They would certainly make the bars lighter.

No.

On aluminum bars, any flaw can one day make them fail. Aluminum doesn't fail slowly like steel, it seems fine and then it's in half.
Steel on the other hand doesn't depend entirely on it's shape for structure and I'm sure you can drill at will. I'd keep it a decent distance from the stem though...

yes.

It's actually one of the most common failure modes for handlebars. That's why bar manufacturers started using grooves to route the cable.

No.

the shop that i worked at in the '80s did it.

the trick was to make a loop of cable housing from a non-aero lever and run it up, back to the bar plug that was drilled for the housing to run through. then out near the stem. We only did it to SLEAVED bars so tht they had extra metal to help prevent failure.

If I remember right only 1 failed! Would I do it today? Hell no.

how big of a scratch are we talkin here....

this thread has been interesting lol~

i certainly would not risk compromising stem/bar strength

Eddy Merckx used to drill out his bike components to shed weight; check out the handlebars on his bike he set the Hour Record on.

http://www.classicrendezvous.com/ima..._Hour-bike.jpg

LINK

Of course, he never rode that bike again.

LINK to useful info

I don't know, because I'm not the one who said that a "scratch" could make bars fail. As far as I'm concerned a scratch is just that and there really aren't too many varying degrees of such. Until of course its deep, but then thats a gouge which I think is something totally different and depending on the severity of said gouge, could at some cause the bars to fail.

RE: the drill bars on the hour record bike..
It looks like they're only drilled where you would put your hands, which is bar far, not the highest stress area of the bar ie. either side of the stem..

just my .02

edit: I didn't click the link below the pic, but there is still a sleeve over the center of the bars... but still making my point somewhat less valid. my b

We drill holes in our mallet heads for polo? Lol.

If I remember right, my old syntace stratos bars had holes in them for internal cable routing. Maybe check out a set of those, and see if you like them.