Drilling frames for internal wiring. Yes or No?

[AndyZ]

Guys I want to clean up the wiring on my 2018 Townie. It is already factory drilled for internal wiring, but I can't fit the main BBSHD harness inside there. I haven't measured yet but I would have to drill two holes approximately 3/8". One near the bottom of the front tube and one near the top. The debate seems to rage on both sides. Some say it is crazy and others say go for it they have done it with no issue.

Has anyone here seen or heard of a frame actually failing in a similar situation? It seems every time anyone wants to modify anything on a bike, people are there to say it will be a catastrophic failure (my LBS told me my bbshd could/would destroy the Townie frame).

I don't want to die, or even get hurt, but if these are unwarranted fears then I DO want internal bbshd wiring :).

[pure_mahem]

Well people put holes in frames all the time to add those nut certs to mount water bottles on. 3/8 isnt really that big of a hole. But Im not looking at your bike to see the proportion it is to the tubing used in your frame. You then though have the counter argument that the nut cert adds support to the hole that has been drilled and reinforces it and the hole is often not in a high stress area of the bike comparatively. I suppose you could drill the hole and have a welder tig a bead of weld around the hole for added strength but then your gonna mess up you paint job and potentially weaken your frame in that area by the application of heat to it. Half dozen of one 6 of the other... not the answer your looking for Im sure. If it were me Id just run all the cords through a long length of heat shrink tubing and secure it to the exterior of the frame as if the bbshd does tear the bike apart its gonna be a little quicker to swap it to another one. But...that clean looking install would look pretty trick! Guess you got a decision to make based on the information at hand as long as your prepared to deal with worst case scenario which id say is replacing the frame or having it welded. I would test it out a bit after I did it and keep an eye on it. Make a point to check it out before and after every ride for stress fractures around the location and dont get complacent about it. Of course this is in my mind anyway more of an issue if its an aluminum frame bike. This is probably non issue with a steal frame. Id say run with it and do it up never gonna know unless you try it. Can you tell I would be indecisive about doing it as well. Sorry all that probably wasnt much help. lol

[AndyZ]

You were the defence AND prosecuter on this one.Thanks for nothing... Just kidding I appreciate the response, but I am no closer to having the confidence to drill a few holes :).

[xcnick]

I am worse than AZguy. I have a Townie, thought many times about it, and haven't done it. I was ridding the Townie on advanced downhill trails when my wife wasn't looking. I couldn't break the thing by trying.

When you put a hole for a bottle cage, it is filled up by the nutsert so the strength comes back. Our holes do weaken things. However they have a hole there already so the math is just how much do we loose by making it bigger. Let us see which one of us succumbs first to the allure of integrating the wires. I will post if I do it.

[AndyZ]

I am worse than AZguy. I have a Townie, thought many times about it, and haven't done it. I was ridding the Townie on advanced downhill trails when my wife wasn't looking. I couldn't break the thing by trying.

Wow that's good to hear. I didn't know they were so tough. Compared to my downhill bike the Townie feels like a match stick, and to be honest I was afraid to even jump curbs with it lol, but maybe my fear is unwarranted.

I am playing with the wiring at the moment to see how much I can clean it up without drilling. I will add pics later when I get something meaningful accomplished.

As for drilling, the factory holes have a reinforcing ring around the hole. Maybe leaving that in tact and drilling right next to it would lend some of the reinforcing ring's strength to the new hole. Hmmm.... Does anyone know how large of a rivnut is available? If there is a big enough one, we could drill a hole, put the rivnut, then drill the threads out of the rivnut and stick our wires through. Although, the rivnut hole may be too round to get the cable through flush. We need an angled or elongated hole.

What do you think?

[xcnick]

Girls townie. Build is on this website. 2.8 WTB Ranger and Dirty Dan up front. I am 150lb and, well, older. Didn't jump off a picnic table, but bounced around at speeds a bit more than one would like with a hard tail.

[AndyZ]

OK I think I found a passable solution. I put some nylon cable mesh over the wires and it looks not bad. The zap strap above and below the battery still drive me nuts a little, but I probably just need to lay down my OCD a little....

[tommie]

That nylon cable mesh looks a lot better than the bare cables, as regards the zap straps get them to match the frame color, not nearly as noticeable.

Also as you`ve a HD there you really need Discs !

[AndyZ]

That nylon cable mesh looks a lot better than the bare cables, as regards the zap straps get them to match the frame color, not nearly as noticeable.

Also as you`ve a HD there you really need Discs !

I just thought of a way to eliminate the zap straps. I can put a regular threaded water bottle insert and then use a cable fastener (see pic). Which would bring me back to the debate.... To drill for a threaded inserts or not :).

As for the brakes... Yeah I would love some 203mm hydraulic train stoppers on there, but it's just too much effort and $ to be worth it to me. I upgraded the stock calipers to Shimano XT mountain bike ones, and upgraded he stock pads too. It stops not too shabby

[commuter ebikes]

I have thought about doing this too, but I won’t because I don’t want any more opportunities for water to get in to the frame.

[AndyZ]

I have thought about doing this too, but I won’t because I don’t want any more opportunities for water to get in to the frame.

Just drill a few more holes to let the water out ;). I'm kidding I'm kidding :)

[JPLabs]

AndyZ, you have a Townie 7D, right? I just looked that up, frame is steel, per what I saw on REI listing. Steel won't have the fatigue sensitivity or heat treat difficulties you get with aluminum. And it's easier to braze or weld a bung on a steel frame to reinforce a larger hole, as well, if you want it strong as new-ish. In case you change your mind....

[AndyZ]

AndyZ, you have a Townie 7D, right? I just looked that up, frame is steel, per what I saw on REI listing. Steel won't have the fatigue sensitivity or heat treat difficulties you get with aluminum. And it's easier to braze or weld a bung on a steel frame to reinforce a larger hole, as well, if you want it strong as new-ish. In case you change your mind....

Thanks very much for looking into that JPL. I'm not sure about USA but our Canadian Townies are aluminum. Mine is 6061-T6.

[JPLabs]

Ok, understood. They seem to offer both materials here, I saw both listed on different models. I'd not make big holes in my aluminum frame, myself. Already crossed that bridge, so i agree with your solution, too.

Thanks for the info.

[AndyZ]

JPL would you have the confidence to drill and tap a few #10 holes in the frame? No insert (which equates to a much smaller hole). This is how I installed my battery on the underside of my Devinci downhill frame (4 tapped holes w/screws plus a velcro strap for extra insurance). The Devinci is built like a tank so I'm not really concerned about it, but the Townie has a much lighter frame. Anyhow, if I could drill/tap 3 tiny holes safely then I can do away with my zap straps and use cable loop holders. It would be such a clean install if it were safe.

[JPLabs]

JPL would you have the confidence to drill and tap a few #10 holes in the frame? No insert (which equates to a much smaller hole). This is how I installed my battery on the underside of my Devinci downhill frame (4 tapped holes w/screws plus a velcro strap for extra insurance). The Devinci is built like a tank so I'm not really concerned about it, but the Townie has a much lighter frame. Anyhow, if I could drill/tap 3 tiny holes safely then I can do away with my zap straps and use cable loop holders. It would be such a clean install if it were safe.

I would not, no, especially not for a battery. I do use the inserts when I do threads into thin material.

A small hole sounds good, sure, but you will have real high local stress, all that battery mass acting on a tiny circle of threads, that's it. I never saw a bike frame thick enough to give even a half diameter's worth of thread engagement for an M6 or even M5. Those tapped threads will be highly stressed, especially if they are all in a straight line - side loads will have huge leverage on that 5mm or 6mm ring of threads. An insert spreads that load over more frame area, it has a flange to resist bending loads better, the diameter is larger (a benefit in this case) and if it does flex, at least the threads have enough support and engagement to be OK.

You don't need the special tool to install inserts. You can do it with nuts and bolts. Youtube knows how.

[AndyZ]

Thanks for that insight. I hadn't thought of the smaller hole being a higher stress point. The bike is not here for another week but when it gets back I will check how many threads are cut into the frame tube. If I remember right I think there are two threads per screw, but I will check. The frame is highly reinforced so if it ends up cracking from either the taps or inserts, hopefully it will give gentle warning signs first before imploding (I feel like it will). See pic for how reinforced it is. Sorry I can't take a close up as the bike isn't here, but there is a thick bar of aluminum on the top side of the front tube running the entire length. I could swap the velcro strap out for some big, tight zap straps. That would at least take essentially the whole weight of the battery.

[AndyZ]