zensuit

I am having a dog of a time getting one bolt to take in my down tube bottle cage braze on...the brze on itself is spinning. I don't have the right brain for solving stuff, so before I superglue it down...tell me real mechanics...what should I try first?

Thanks in advance,

Z

RegularGuy

You have a loose rivnut. A competent bike shop can replace it. I know, because I've been there myself.

zensuit

Thank you, any reason why I can't take it out and replace it myself??

RegularGuy

You'll need better advice than I can give you on this BUT...

I think that it takes a measure of brute force to remove the bad rivnut, and a special tool to install a new one.

Rev.Chuck

A quick and dirty trick for the loose rivnut:

Get a capscrew(bolt), nut and washer of a size to fit your rivnut. Make sure the capscrew is long enough to thread fully into the rivnut with the nut and washer already on it.

Thread the nut onto the capscrew all the way and then put the washer on.

Now thread your "tool" into the rivnut.

While holding the capscrew steady, turn the nut down tight onto the rivnut. Don't wring it off but get it pretty tight.

Back off the nut, remove your "tool" and install your bottle cage.

A rivnut works like a rivet, what you have just done is grabbed the part of the rivnut the expands by putting your capscrew in it and expanded it(more) by tightening the nut. Works pretty good. I have the tool for this but still use this trick to snug them up because it is easier and often the frame is to small to get the tool, which looks like a rivet gun, into the frame.

By the way removing them can be a real pain, once they have been expanded even a little they won't fit back through the hole.

RegularGuy

Slick!

zensuit

That is sick. Thanks. See what I mean? Some people just get it. I'll try it.

Z

PriO

LOL zen at the superglue thing
i use to be like that

MudPie

So they're not actually brazed on?

Astra

MudPie, If it's a riveted boss, chances are it's an aluminium frame. Try brazing it and it might just set the frame on fire .

zensuit

Well, duh. I wasn't even thinking about the frame material...guess I won't mess around with the torch, lol.

rykoala

So does this mean that if I wanted another bottle cage on my bike (a 3rd) that I could just just buy a couple of rivnuts, very carefully drill the holes, and install the rivnuts using Rev.chuck's advice? Sounds too easy....

Of course, screwing up could ruin the frame, and all that jazz, but is that how framebuilders do it w/o brazing? Or is this on aluminum only bikes where you obviously can't braze?

I've tossed around the idea of adding a 3rd cage to my steel framed bike...

Astra

With aluminium (or is that aluminum..?) I guess 'braze ons' are either welded on whilst frame is being made or riveted on afterwards.

Owning a proper steel bike, I guess I wouldn't know .

ComPH

This link: https://www.biketoolsetc.com/index.cg...ame%20Building offers all sorts of rivnut as well as mounting tool, the right drilbits, etc.

WonkerJaw

What if you can't get the bolt out of the rivnut? The rivnut just spins inside the frame.

Rev.Chuck

First, while you can install a rivnut with the quick and dirty tightening method, it is a pain in the butt. Much easier to use the rivnut tool for that. I am not a big fan of drilling more holes in a light alloy frame. Probably you would not cause any harm as long as you keep the hole smooth (no stress risers) But it would be simpler to just buy a seat mount cage holder if you need more water bottles, you can take it on and off pretty easy. I use one for my long fixed gear rides.


WonkerJaw, you have a bigger problem. I have managed to get the screw out by grabbing the lip of the rivnut with a good pair of needle nose pliers and then unscrewing the screw. i have also had to strip the frame to find the biggest interior vent hole, then carefully grind the lip off the rivnut dropping it into the frame and then shake it out and once or twice I have used weatherstrip adhesive to glue the remains of the rivnut to the BB shell because I could not get it out. Now install new rivnut

zensuit

You know your shiznit. I am impressed.

WonkerJaw

You know your shiznit. I am impressed as well... thanks

Rev.Chuck

What can I say, I used to work at a C-dale dealer and went thru this a BUNCH of times. Thanks

WonkerJaw

Rev.Chuck,
I have an old C-dale F5 with a 60mc(?) Head Shok. I use it for commuting only. I was wondering if there is a cheep way to lock out the suspension for a more efficient road bike... or should I not even mess with it and find a good used road bike?

Thanks,
WonkerJaw

Rev.Chuck

F5 was after my cannondale days. The best thing is a road bike. But, I have, for years, used pvc pipe to adjust my non adjustable springs preload. This was on motorcycles. If you can figure outthe right length to get the top cap tight on a piece of pvc you could insert in place of the spring or even in the air chamber. I have never tried it in place of a spring but for a couple of bucks you might give it a try.

WonkerJaw

A piece of PVC... is your real name MacGyver? Thanks for the tip

ultra-g

This seems pretty common. My brand new LeMond is suffering from a loose braze-on (or rivet?) on the down tube water bottle mount.

I tried unscrewing it by holding onto the rivnut with needle nose pliers like Rev.Chuck mentioned, but I only ended up scratching the paint off, so I stopped as soon as I knew I was getting into deeper mud with it.

I'm just taking it back to the bike shop Friday for them to fix.

henrys

I was about to buy some Rivnuts (aka Nutserts) to do this job, but I have found a simpler way using Nylon nail anchors that works for me.

For a 5mm Rivnut you need to drill a 7mm hole in the frame tube, but I used a 5mm Nylon nail anchor so I only drilled 5mm holes in the frame tube. I also felt happier about using a plastic insert than a steel one, which as this thread shows can get loose. And the 5mm hole only removes half the metal of a 7mm hole. BTW Park Tools has a brilliant way of using an axle and QR skewer to re-tighten a Rivnut, see https://www.parktool.com/repair/printhowto.asp?id=147

Anyway, the "nylon anchor" or "nail anchor" looks like this, see:
https://www.plastic-anchors.com/nylon..._lengthend.htm

Don't worry I didn't use nails to hold the bottle cage on, I'm not quite that rough .

I pushed a short nylon anchor into the hole. Then I used a small gauge (#2 or #4) pan (cheese) head self-tapping screw about 12mm long with a washer under the head, and it was enough to expand the nylon anchor into the hole for a firm grip. It's easily strong enough to hold a large bottle. I also found that trying a larger screw made the anchor rotate, the small one went in easily with just the screwdriver force being enough to prevent rotation. And there won't be any seizing up problems with this.

IMHO the biggest risk is in drilling the holes, to get the locations right, the separation (64mm) right, and preventing the drill bit from punching through to hit the opposite side of the tube causing a dimple. That requires careful control of the drill and ensuring the bit is made too short to reach the other side.

I've done it on a steel frame, next I'll do my Alan.

So what do you reckon?

Henry
Western Oz

jsharr

I know there is a method where you use a hub and a quick release skewer to install riv nuts. Might work to tighten a riv nut., but I cannot recall exactly how it works.