brokewheelspoke

Watched some videos on this, and they say to use aluminum rivnuts. Is there a reason you need those, or could you just use an m5 tap on holes direct into the frame?

alcjphil

The frame tubing is too thin for a tap to work properly

brokewheelspoke

Alright, makes sense.

Crankycrank

Also make sure where you're drilling the tubing is not beer can thin as some alu tubes can be. A rivnut can pull right through.

Iride01 

I was happy enough just holding the cages on with hose clamps. No one ever commented on them, so many probably never noticed them.

I put a strip cut from a old inner tube between the clamp and the frame. When I took the bottle cages off years later when I got rid of the bike, the paint was still in good condition.

Not all cages will work well with hose clamps.

If you do drill into the seat tube, make certain it will be below the seat post.

mpetry912 

the only thing I can think of is something like a drywall anchor that expands to fit the hole tightly as the bolt goes in.

and use some JB Weld to ensure it is locked in.

I am pretty sure I have seen hardware like that somewhere

Otherwise I don't know what to suggest

/markp

SurferRosa

Folks use rivnuts.

t2p

recommend first to consider other options including water bottle cage adapters

SKS ... Zefal ... Granite Design ... Velo Orange ... Topeak (?) ...

Steve B.

These Shimano cable housing stops are designed to screw onto a frame mounted bolt. There is nothing stopping you from drilling a hole on both sides of the downtube and using a long through bolt, thru the downtube plus nut on one side. I would not do this, but depends on age and value of frame. I drilled out/made larger the cable stop holes at the top of the downtube on my new Spec. Chisel so as to run the e-tube cable for a Di2 shifter system.

https://www.amazon.com/SHIMANO-Housi...19707293&psc=1

KerryIrons

Correction: The frame tubing is WAY, WAY, WAY too thin for a tap to work properly

brave17

I would suggest buying (or 3D printing) bottle cage adapters instead.

Schweinhund

Don't drill holes. don't use expansive type nut/drywall inserts. have it done right or don't do it.
Use whatever bottle cage kit is recommended above ^

bboy314

I would (and have plenty of times) use rivnuts.

WizardOfBoz

Arghhh! Please, no, no, no! The plastic anchors are weak and can wobble. You have a heavy load on the anchor. You have a sharp aluminum edge where you drilled and this can cut into plastic anchors. This arrangement is likely to pull out and ruin your frame. The proper built-in approach is a welded adapter. A rivnut can be servicable (it's metal, it won't be sliced by the sharp edge of the frame, and it clamps very strongly to the frame around the hole.) If the frame is thin, then using a wide hoseclamp with a rubber grommet (mentioned above) may be the best approach.

A key goal is to spread out the stress rather than concentrating it in one point on the frame.

Last, a point about metal screws in sheet metal. Don't do this in your frame - it's likely too thin. But for other applicatipons, drill way undersize, and use a sharp punch to dimple the metal inward. Then install the screw. This gives you more metal to grab the screw and spreads the stress out to a larger area.

By drilling undersize, and using a needle punch to push a bit of metal to the back of the sheet, you are forming a bit of a "nut" behind the sheet. The picture below shows a very specialized screw that targets the same goal but without a punch. For this specialized fastener, you drill undersize and the ramp and thread pattern swages a nice set of threads in the metal.

Trakhak

Use rivnuts. That's what they do at the factory for both aluminum and carbon frames.

How To Add Bottle Cage Mounts To A Bike Frame

mpetry912 

wow that is a very trick piece of hardware. Similar to the item I mentioned in my post.

/markp

WizardOfBoz

Mark,
Maybe I was thinking of the cheap plastic anchors and you are aware of and had in mind beefier ones?
I do think rivet nuts of some brand are the purpose-designed product in this case.
If I'm being overly confrontational, sorry. In my defense, I'm an engineer. And I read stuff like "Carroll Smith's Nuts Bolts Fasteners and Plumbing Handbook" in my spare time.
Best,
Jim

Paul_P

In addition to my two original bottle cage mounts used for water bottles, I use three additional SKS "Anywhere Adapter Bottle Cage Mounts ".

Two with regular metal bottle cages : one for a water bottle on rear of my seatpost and one for stove fuel under my down tube.
The third one mounts my Topeak Mountain Morph pump (and its holder) to the seat tube.

RCMoeur 

I have had M5x0.8 rivnuts on my Chicago Schwinn steel cruiser frame for over 30 years with no problems. They should work in thinner aluminum frames, although I have seen Al tubing wall failures where the rivnut had wobbled out or pulled through. But these are the exceptions and not the rule. And as noted above on the seat tube they will act as a bottom seat post stop, so plan accordingly.

mpetry912 

absolutely no worries buddy ! I'm a big "Prepare to Win" fan !

I have seen an aerospace type thing that goes thru a hole and then expands out like an umbrella, giving the thing a large surface area inside the tube.

like a drywall anchor. Blind riv-nut maybe ? this will get you started, something like this. Check out McMaster-Carr or Aircraft Spruce and Specialty.

Threaded Insert Jack Nut Riv Nut Blind Nut 25 Pack #10-24x0.91' Insert Nut Blind Nuts Threaded Rivets Nut inserts Steel Threaded Rivet Blind Fastener Threaded Insert For Metal Super-deals-shop (dtidyhere.shop)

And if it were me I'd dip the thing in JB Weld, and then put it in the hole and tighten it down with the bottle cage attached and let dry.

this is a tricky problem to solve.

/markp

spclark 

I just hung a CF bottle holder on my '72 Motobecane with zipties. With a piece of old inner tube between it and (what remains of the original frame) paint it's solid enough to hold a full bottle & stay in place when I put the bottle back.

Trakhak

Having installed rivnuts in my days working in bike shops, seems like a trivial problem to me. As I said earlier, anyone can buy simple rivnut sets and install them. And no complicated tool is required - just a drill and the appropriate drill bit, a 5-mm bolt, a 5-mm nut, and a washer. See the video I linked to a few posts above this.

By the way, if anyone encounters a loose rivnut in an aluminum or carbon frame, the same tools and technique used to install the rivnut can and should be used to snug it up again. Just last year I walked a friend of mine through a rivnut repair on his Trek Roubaix.

Edit: as always for a job like this, measure repeatedly to confirm the correct placement and orientation of the holes before you drill.

brokewheelspoke

Alright, 3 out of 4 rivnuts successfully installed. The question is will that be good enough. You can see in the photo (circled in red) the hole I couldn't get the 9/32" drill bit into, even with my right angle adapter. I did not want to try to drill at an angle. Unfortunately, the right angle adapter only takes the hex type drill bits, not standard ones, so I doubt I can find a shorter bit of the same size that would work. Don't think I'm going to go so far as buy a right angle drill.

I was able to get a smaller drill bit in that hole so that I could tap it directly for the m5 screw, and it seems to hold. I put a small washer behind the cage, just so it's somewhat matched in height and aesthetic to the rivnut.

This was a Trek FX frame that Trek deemed too small for two cages. The original downtube cage mounts were way too far down to allow for a seat tube cage, so I had to make 4 new holes altogether. But it works, holds two 20oz bottles without interference, can get them in and out without a problem. Overall, I'm pretty happy with it.

brokewheelspoke

Update: was able to get the 4th hole drilled out by using a stepped drill bit with a 9/32 step. Was just short enough to get in there with the right angle adapter.

sweeks

Oh, come on... all you really need is one thread!
(/s... just in case anyone thinks I'm serious!)