Is it safe to drill cable routing holes into aluminum handlebars?
#1
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Thread Starter
Is it safe to drill cable routing holes into aluminum handlebars?
Hello all, I’m wondering whether it’s generally considered safe to drill holes (well sanded-off, of course) for cable housing through aluminum drop bars. I’d like to be able to route the cables from my bar end shifters—and maybe also my brake cables—through the bars so that my grip on the bars (as well as the look) is cleaner. It’s for a touring setup with disc brakes and with all the time my hands will spend on the bars, I’d love to have the feel be as comfortable as possible. If it’s safe to drill cable housing-sized holes into Salsa Cowchipper bars without compromising their structural integrity (or my shifting/braking/moral integrity), I’d be into it.
Thanks as ever for your help.
Thanks as ever for your help.
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Should be no problem at all. I drill large holes in my frame and bars all the time.
If you really want a clean comfortable grip though I would suggest eliminating brakes/cables altogether. This will also reduce the overall weight of the bicycle and make you much faster
If you really want a clean comfortable grip though I would suggest eliminating brakes/cables altogether. This will also reduce the overall weight of the bicycle and make you much faster

#5
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If you're really carefyul, it's safe to drill holes in aluminium handlebars. What's not safe is using that handlebar after it's been drilled. A handlebar that is factory made with holes in them are beefier than a handlebar not designed for a hole.
Cheers.
Cheers.
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People have been drilling aluminum bars since the advent of aero brake hoods. Some had good luck while others didn't. There is a reason you don't see manufactures sell aluminum bars with holes drilled in them for your purposes. This should be a good indication that it isn't the wisest thing to do at this point. Though, I can understand your reasoning, it would look cleaner but this may come at a cost.
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#8
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Should be no problem at all. I drill large holes in my frame and bars all the time.
If you really want a clean comfortable grip though I would suggest eliminating brakes/cables altogether. This will also reduce the overall weight of the bicycle and make you much faster
If you really want a clean comfortable grip though I would suggest eliminating brakes/cables altogether. This will also reduce the overall weight of the bicycle and make you much faster

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Don’t do it. Avert your gaze from the cables or seek out and order drilled handlebars.
Last edited by Ghazmh; 12-12-20 at 01:16 PM.
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#10
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Ok! Very strong responses here, point taken. I’ve seen other threads where people speak about drilling routing holes in bars for these purposes, but they must not be aluminum bars (steel I guess?). Thank you all for your help, I’ll stick with the bars such as they are.
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#11
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People have been drilling aluminum bars since the advent of aero brake hoods. Some had good luck while others didn't. There is a reason you don't see manufactures sell aluminum bars with holes drilled in them for your purposes. This should be a good indication that it isn't the wisest thing to do at this point. Though, I can understand your reasoning, it would look cleaner but this may come at a cost.
#12
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The BIG PROBLEM with drilling holes in an aluminium dropbar for brake cables is that you introduce to very large stress risers of which the one at the brake lever is most likely to cuase the handlebar to snap. The hole under the handlebar at the stem need to be in a strongly reinforced area and they must be oval to allow the cable housing to exit. There again a high risk stress riser is created. A snapped handlebar in traffic or at speed is no jopking matter and usually results in a crash.
DON'T DRILL HOLES In ALUMINIUM DROPBARS!
Cheers
DON'T DRILL HOLES In ALUMINIUM DROPBARS!
Cheers
#13
Stevoo
This topic comes up every once in a while.
DON'T DO IT!
I have personally seen bars break because of this.
The kicker is my buddy who had drilled bars and had them break asked me to drill his replacement bars. Yup, he really did and was serious. Showed up at my house, bars in hand and really pressed me to drill them. See, he is not one to use tools or do mechanical stuff so he was looking for someone to do the job. Wanted holes drilled right near where the stem clamps. Jeezo
I told him nope, it is not safe. They will break. I was blown away that he did not learn or understand that this was a really bad thing to do. I think he kept asking around until he found someone to drill the replacement
Maybe this was the thing to do in his cycling club. He had shared a story years later about a member decending Mt. Diablo that had her bars break. I never thought to ask if her bars were drilled.
DON'T DO IT!
I have personally seen bars break because of this.
The kicker is my buddy who had drilled bars and had them break asked me to drill his replacement bars. Yup, he really did and was serious. Showed up at my house, bars in hand and really pressed me to drill them. See, he is not one to use tools or do mechanical stuff so he was looking for someone to do the job. Wanted holes drilled right near where the stem clamps. Jeezo
I told him nope, it is not safe. They will break. I was blown away that he did not learn or understand that this was a really bad thing to do. I think he kept asking around until he found someone to drill the replacement
Maybe this was the thing to do in his cycling club. He had shared a story years later about a member decending Mt. Diablo that had her bars break. I never thought to ask if her bars were drilled.
#14
Senior Member
I've found that dragging my feet on the ground works much better. Granted my saddle height isn't ideal since I dropped it to make sure I could get my heels on the ground for full braking power, but since I make the change I haven't gone over my handlebars.
#15
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I love running the housings along the front of the tops,just far enough down that they lie under my second knuckle. Feels totally natural and better than simple round.
I reserve holes in the handlebars to outboard of the brake levers. (So far, I have never had a reason to add any out there. Maybe I went to bar end shifters.) I've broken (old and tired) bars at the edge of the stem butting. Drilling holes to speed the failure? Nah.
I consider everything in a line from the road under my front tire to my hands (front wheel, fork, steerer, headtube, stem and handlebars) something close to sacred. I know from first hand experience that failures in that line can be life and death.
I reserve holes in the handlebars to outboard of the brake levers. (So far, I have never had a reason to add any out there. Maybe I went to bar end shifters.) I've broken (old and tired) bars at the edge of the stem butting. Drilling holes to speed the failure? Nah.
I consider everything in a line from the road under my front tire to my hands (front wheel, fork, steerer, headtube, stem and handlebars) something close to sacred. I know from first hand experience that failures in that line can be life and death.
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#16
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#17
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I may as well start a new rumor. Will electronic braking be included in the 2022 Di2 groupset?
#18
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Thread Starter
Should be no problem at all. I drill large holes in my frame and bars all the time.
If you really want a clean comfortable grip though I would suggest eliminating brakes/cables altogether. This will also reduce the overall weight of the bicycle and make you much faster
If you really want a clean comfortable grip though I would suggest eliminating brakes/cables altogether. This will also reduce the overall weight of the bicycle and make you much faster


https://www.bikeforums.net/classic-v...e-routing.html
#19
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Could be the end results of your reference thread is why we all know now how bad an idea it is.

#21
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So it sounds like OP got the point but for future people reading the thread: If you are asking if something is safe, you probably shouldn't do it. Even if something might possibly turn out safe that doubt can lead to some dangerous situations. You could say what if that hole cracks and not pay attention to what is going on around you and boom you hit something or someone. If something wasn't designed with your use in mind, find something that is or just re-kajigger your expectations and use as intended. Be safe always, the won't look all that clean after a crash

#22
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So it sounds like OP got the point but for future people reading the thread: If you are asking if something is safe, you probably shouldn't do it. Even if something might possibly turn out safe that doubt can lead to some dangerous situations. You could say what if that hole cracks and not pay attention to what is going on around you and boom you hit something or someone. If something wasn't designed with your use in mind, find something that is or just re-kajigger your expectations and use as intended. Be safe always, the won't look all that clean after a crash

Cheers
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#23
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done it to drop bars. I kept the hole size within 1/32 of the cable housings used. Made them oblong holes, set on the left & then on the right that allowed for two cable housings each to pass thru. The holes face downward as much as possible.
If i could have bought bars with the holes already, I would have done so.
Going on 4 years in service.
If i could have bought bars with the holes already, I would have done so.
Going on 4 years in service.
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I’ve had it done but not to regular Aluminum bars.Had them custom made with double tubing.It was a real PITA.The holes are right after the bend but before the bar ends.Holes drilled in bars is suicidal.

Last edited by 7up; 12-17-20 at 11:13 PM.
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