Tapping Bottle Cage mount
 

Have any of you tried taping the frame to add a bottle cage? I've read mostly MTB folks saying not to. I'm trying to avoid zip ties or those clamp mounts. If it's not safe I'll just go another route. The LBS says I'd have to get it done at a machine shop but I'm confident I could do it.

Ultimately, it depends upon the bike, and where you plan to drill. You haven't provided that information. So I'll say there is a 95% probability that the answer is NO, unless your frame is carbon, in which case the answer is 100% NO.

Nearly every bike that has bottle cage mounts uses reinforced bosses brazed, welded or molded into the frame. This provides reinforcement to compensate for the increased stress around the holes. And it provides enough material thickness to have enough threads to avoid stripping them when tightening the cage bolts. If you just drill and tap into the frame, there is a good chance the threads won't hold, and the possibility that your frame will develop fatigue cracks at some point, especially if it is aluminum or titanium.

Tapping Bottle Cage mount
 

It's steel and I was thinking about tapping in the typical area on the seat tube.

I reused an old reflector mount but the bottle shakes a lot.

If you drill a bigger hole , then you can expand a Riv-Nut in the hole, its threaded . (a common way of doing such fittings in Aluminum)

+ there are several ways to temporarily strap on a bottle cage, two Fish uses a velcro strap and a half round rubber block.

Bottle cage installation with riv nuts

If it's steel, and you use Rivnuts or similar threaded fasteners, you've improved your chances of success. Not having threads cut directly into the frame reduces the stress concentration considerably, though the enlarged hole offsets that to some degree. I'm no expert on the stress distribution in a bicycle frame, but I'd imagine the seat tube is a better place to experiment than the down tube. Two things to watch out for when using Rivnuts: choose the same material for the Rivnut as the frame to avoid galvanic corrosion; and avoid drilling the hole oversize to avoid having the Rivnut work loose and spin in the hole.

EDIT: I watched the video. The use of JB Weld Epoxy on the Rivnut is probably good insurance to keep moisture out of the frame and reduce the risk of the insert working loose. Thanks for posting that.

Tapping Bottle Cage mount
 

Pretty cool thanks for the video!

I'm sure the Riv Nuts would work, but........ something in my head says that stressed bike frame tubes aint the place for drilling and crimping. I could be wrong, and it could last safely for years, but um.....

Riv nuts... I did one bike about 20 years ago and it is still chugging along. Steel frame.

Aaron :)

the crimping, shortening, in length is making it do an expansion in diameter.. pushes out into the hole.

Tapping Bottle Cage mount
 

So is the rivnut threaded?

Yes. Rivnuts work somewhat like pop rivets. The installation tool has a threaded mandrel that the Rivnut is threaded onto. Once the Rivnut is inserted and compressed, the part of the Rivnut on the "back" side of the hole flares to lock it in place. Then, the mandrel is unthreaded from the installed Rivnut. Unlike pop rivets, the OD of the Rivnut typically does not expand to fill the hole. If it did, the threaded ID would also grow, which would make for very loose threads. This is why the hole needs to be drilled accurately. In a former career, I used quite a lot of Rivnuts on steel sheetmetal work. The best we could achieve was about a 90% success rate of having them installed without spinning in the hole. Odds on a round-section bike tube may be higher, as the shape of the tube might act as a key to keep them from working loose. The epoxy idea might help there, as well.

Bikes have had seat and down rubes drilled and tapped for bottle cages or other applications for eons. Assuming one uses good practice, any frame can be safely drilled for a riv-nut, or a bonded thread insert. Tapping the tube directly usually isn't an option because there's not enough wall thickness.

Builders don't have any magic formulas,or secret methods for drilling holes, and you can do the same as them --- if you do it right.

Weird. I didn't know there were power tools a billion years ago. :p

Yes...

I also like the idea of setting them in epoxy (JB Weld). I did not do that with mine, but they grabbed hold and held tight. I don't own that bike any more but I still see it occasionally.

Aaron :)

If the application ever comes up again, coat the back of the sheet stock with coarse lapping compound. When the riv-nut begins to compress it presses the grit into the rim and sheet stock, forming a mechanical lock which will keep it from spinning.

HERE IS A GREAT SOLUTION THAT INVOLVES NO DRILLING AND THIS BOTTLE CAGE WILL REMAIN SECURE AS LONG AS YOU use "Super Weatherstripping Adhesive" (comes in small tube, available at auto parts stores such as Auto Zone, O'Reilly's, NAPA, Advance, and others.....specific brand names will be 3M -or- Permatex..., possibly others....YOU DEFINITELY DO WANT THE PRODUCT THAT SPECIFICALLY STATES "super weatherstripping adhesive" !! )


This is the Specific Bottle Cage that you want to buy, it is inexpensive and Walmart & Target have been known to carry it. I have installed this exact particular Zefal pulse UNIVERSAL Mount BOTTLE CAGE With VELCRO STRAP upc code 7 68661 55039 4
on to more than twenty bicycles using "SUPER WEATHERSTRIPPING ADHESIVE" applied to the thick rubber universal mounting block that is part of this Zefal cage.
It is my opinion that if you simply try to use and install this Zefal cage with only the velcro straps tightened & WITHOUT ANY SUPER WEATHERSTRIP ADHESIVE, you will get generally poor results as the cage will move & slide under most riding conditions!!
IF YOU APPLY "super weatherstripping adhesive" before you attach it to the bike and then pull the velcro straps tight......the cage mount WILL NOT MOVE!
You can also choose if you wish to use a different cage than the black zefal one that is supplied. On several KOOL LEMON colored early seventies Women's step through COLLEGIATES, I obtained matching yellow colored cages frrom various web sources, and the appearance result was fantastic. This Zefal product has two 3mm Allen key headed screws that you can unscrew to remove the supplied black cage, and then probably swap many other cages.
The thick rubber universal mounting block is very well made and looks great when installed and the excess velcro strap is cut down such that only enough remains to secure it without any excess overhang. NOW ON THIS zefal PRODUCT'S CARBOARD PACKAGING it says "FITS MOST BIKE FRAMES".............my guess is that it might do fine or okay as supplied WITHOUT "super weatherstripping adhesive" on possibly bicycles with fat diameter tubing, but it is my experience that for classic old steel bikes with narrower diameter tubing, YOU WILL DEFINITELY NEED TO BUY "super weather adhesive" and APPLY THAT TO THE RUBBER UNIVERSAL MOUNTING BLOCK before cinching tight the velcro straps.
You can probably find this Zefal pulse Universal Mount Bottle Cage with Velcro Strap on Amazon too. I bought all of the ones that I installed from my local Target & Walmart stores. Three different people asked me recently about what & how I attached the bottle cages to some of my vintage bicycles. I thought I would mention this solution again here on bikeforums. You do need the small tube of "super weatherstripping adhesive" from one of your local auto parts stores!!!

It seems much easier to go with something like a fidlock and just epoxy the bracket to the frame. No drilling necessary.

https://www.walmart.com/ip/Zefal-Pul...lack/239504228

https://www.3m.com/3M/en_US/p/d/b40069430/

Bottles & Cages ? Zéfal USA


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