Will a rivnut replacement work?

smead · #1 07-09-2020, 01:52 PM

Hi folks. I've had an '03 Allez Pro for years, great training frame, but the rivnuts became looser and looser to the point now where I could not get the bottle cage bolt out, had to hack it out and remove the rivnut from the BB. I see M5x12 rivnuts on Ebay for cheap, but I'm wondering if they will work. For years of spinning the old rivnut in the frame hole trying to get it to bite when replacing cages, I'm thinking the hole in the frame is now going to be too big for a new rivnut to expand and clamp in. Time for yard art? Curious what others think who have done rivnut replacements. Oh and I assume I don't need the rivnut install tool, just a nut to fit any long cage bolt and hold the nut and screw the bolt in to pull up on the rivnut to expand it.

ultraman6970 · #2 07-09-2020, 02:40 PM

If the hole is tad larger, just get a larger diameter rivnut.

This is one of the repairs never done but from the videos doesnt look like super hard, Drill the old ones from the top and good to go. Plenty of videos moving around, did you check them?

Measure the hole and look for the rivnut that fits better. Worse can happen is that you will be running that with a 1 mm bigger nut. Doubt will be a problem.

smead · #3 07-09-2020, 03:39 PM

Yes I did and agree it looks pretty easy, was just concerned the hole would be too big for what appears to be the 7.25mm OD size that I'm seeing for bike rivnuts. If you can point me to a link that has other sizes (slightly bigger OD) that'd be great. Thanks!

prototoast · #4 07-09-2020, 03:46 PM

Can you measure the hole in the frame? As long as the hole is less than the head diameter, if you use a little epoxy with the rivnut, it'll hold well.

polyhistoric · #5 07-09-2020, 03:51 PM

Check with a local shop - there is a Riv-nut tool and maybe it can get the rivet tighter. I had a couple seatstay riv-nuts replaced on a Specialized frame at a shop a couple weeks ago. $30 and no sweat on my part.

smead · #6 07-09-2020, 04:08 PM

The rivnut has been removed (cut out), so it is trashed. Not sure what the orig hole size was, but it is now around 8.25-8.5mm, I suspect somewhat bigger than when new. Not sure if a new 7.25OD will expand enough to fill it. If anyone can point me to a source where I could find something with a 7.75OD that'd be great. There's rivetsonline, but it's all in standard size and am not sure what I'd end up with would work. I suppose I could just order the 7.25 ones off ebay for $9 which isn't a big deal if they don't work ...

prototoast · #7 07-09-2020, 04:28 PM

Quote:

Originally Posted by smead

The rivnut has been removed (cut out), so it is trashed. Not sure what the orig hole size was, but it is now around 8.25-8.5mm, I suspect somewhat bigger than when new. Not sure if a new 7.25OD will expand enough to fill it. If anyone can point me to a source where I could find something with a 7.75OD that'd be great. There's rivetsonline, but it's all in standard size and am not sure what I'd end up with would work. I suppose I could just order the 7.25 ones off ebay for $9 which isn't a big deal if they don't work ...

Yeah. 8.5 isn't too large for a standard bike rivnut. They expand. If you're anywhere near where I am, DM me and I can help you out with this.

bikinchris · #8 07-09-2020, 05:36 PM

You might have been able to retighten the old rivnut in the frame if you had done it early enough.

Peter P. · #9 07-09-2020, 07:31 PM

See McMaster-Carr for all your rivnut needs!

If you're not sure what size will work in the hole, why not experiment with a piece of sheet stock from your local hardware store?

Of course, you'll have to buy the appropriate drill bit, but it seems McMaster-Carr must have some style of rivnut to meet your needs

You could always drill out the already oversized hole to accept a 6mm bolt instead of the nominal 5mm. It won't be a deal breaker for the frame and will work just fine.

smead · #10 07-09-2020, 10:13 PM

Quote:

Originally Posted by Peter P.

See McMaster-Carr for all your rivnut needs!

If you're not sure what size will work in the hole, why not experiment with a piece of sheet stock from your local hardware store?

Of course, you'll have to buy the appropriate drill bit, but it seems McMaster-Carr must have some style of rivnut to meet your needs

You could always drill out the already oversized hole to accept a 6mm bolt instead of the nominal 5mm. It won't be a deal breaker for the frame and will work just fine.

That's a great source for rivnuts - thanks! Not sure I can make the hole bigger due to the non-round aero shaped DT. We'll see ..

bigbill · #11 07-09-2020, 10:50 PM

Quote:

Originally Posted by bikinchris

You might have been able to retighten the old rivnut in the frame if you had done it early enough.

I did that on my Ti Serotta. I was able to clamp one edge, chase the threads with a tap, and used a bolt with washers to pull it tight. The previous owner had cross threaded a cage bolt and broke it loose.

matthewhelmuth · #12 07-10-2020, 10:07 AM

If you anticipate any more rivnut replacements in your future, the astro pneumatic 1442 kit on Amazon is a handy tool and comes with a bunch of different sized rivnuts. Makes the process quite easy.