Cannondale Evo - Broken Fr brazeon tab

[Calnago]

Have any of you Cannondale experts replaced a broken front derailleur brazeon tab? I need to replace one on a 2012 Supersix Evo. Was wondering if anyone knows if there is a backing plate on the inside of the seattube where the 3 rivets will go. Suppose I'll find out later this week but thought maybe someone out there has done this repair and could advise of any tricks or pitfalls to be aware of. Thanks.

[BeeBee30]

Can't you just remove all of the tab and fit a clamp adapter or clamp on mech?

[Calnago]

The tube shape down there is anything but round, hence a clamp on adaptor wouldn't work. And I want a clean, as new, factory type install. I don't have a problem removing and riveting a new tab on, just wondering if there's any backing plate on the other side (inside the tube) that I need to be aware of. I suspect not, but just throwing it out here in case someone who's done it before has any words of wisdom.

[spud]

never done that repair, so I'll defer to those who have. At a minimum, I'd drill only the top of the rivet, I would not try to drill through the hole as you will only open it further, until I was sure I needed to do so.

Also, you might remove all but one of the pins by pushing them through, then start to rivet on the new mount. After setting the first one or two, then push through on the last pin in case there is a backing plate held on with the rivet pin.

[Calnago]

Yes, definitely will just remove enough of the rivet heads to be able to push it out, no intention of touching the hole itself. But you do need to remove all of the rivets first in order to remove the tab and fit the new one. Holes should line up just fine between the new tab and the existing holes. If not, then I'm calling Houston, cuz we have a problem. Also, I'll be doing the removal with the frame in a stand upside down to ensure that bits of the rivet that get popped out on the inside will fall out through the seat tube and not find their way into any chainstay or something. Also, the whole operation will give me a chance to fix his creaking bottom bracket. Frames these days! Sheesh!

[cerro]

There isn't a plate behind. The store I was working in changed 2 or 3 tabs. Possible to order from Cannondale

[Calnago]

Thanks Cerro. Already have the new tab and the three rivets. Doesn't appear too difficult a repair then? Just remove the old one and rivet the new one in its place.

[ProEvoSLTeamHighMod]

Remove the old one (pop heads off rivets), install new one... put some epoxy on there for good measure and stiffnesses. Very easy, no need to drill into frame, no backing plate...
have fun!

[Calnago]

Thanks, think I'll skip the epoxy... if the original was just held on with rivets don't see the need to use epoxy on the replacement (also, what if it were to break again... wouldn't want the broken one epoxied to the frame). Rivets hold it just fine. It broke at one end of the the slot where the derailleur attaches.
@ProEvoSLTeamHighMod: Have you actually done one of these repairs yourself, or seen someone do it first hand?
And yes, seems easy as long as you have the tools, which I do.

[Butcher]

In the process of building a few bikes with EPS [the frame was not made for EPS], I have drilled many rivets to get rid of the cable end stops. The trick is to use a slightly larger drill bit [than the rivet] and drill the head off. Once the head is off, the rest of the rivet gets pushed back into the frame. I'm certain you are aware of issues you will have if you use that same drill bit to go all the way through the frame.

Sometimes it's hard to center the drill bit cause the inside portion if the rivet is not recessed inside the rivet. That's the most frustrating part since, the drill bit is just walking all over the place. Using a dremel works when it gets real bad.

[goodboyr]

Yup. What I do is crater the head of the rivet with a tungsten carbide dremel bit. That way you minimize the drill bit walking first. And as butcher says, once you break through the rivet, its nothing to go right through the other side of the frame. Tape around the drill bit marks the depth you don't want to go past. Good luck!

[SLCBrandon]

I've done many of these repairs and I would recommend epoxy for sure. Eventually the rivets will "wallow" out either the frame holes or braze on or both. The epoxy does as much or more than the rivets to hold the piece flush to the frame.

[Calnago]

I've never seen a riveted brazeon come loose. And if it does, I can redo it. If I see there was epoxy used in the original factory install, I'll use it again (once I get it off). But if not, I'll do it the same as it was done at the factory.
What kinds of frames did the rivets wallow out on you?

[ibcyclist]

I had a brazeon tab actually crack. I got a Cannondale dealer to replace it without any trouble. $50 for the parts and whatever the dealer charge was. The dealer was a bit nervous about it at first, but said afterwards that it was simple. I was using Campy SR mechanical. Not sure if it was torque from the derailleur, over tightening at the brazen, or a combination of both.

[SLCBrandon]

You seem to know more than me. Carry on.