# Advice on repairing a Miami dropout



## Nickinator (Aug 2, 2019)

Cracked drop out with braize  on it, removed it and this is the damage,  anyone have any good suggestions on fixing this? Local welder thought the frame should be uncrimped and a new section fit in LOL I don’t think so.

I don’t think this little section can be reinforced enough, I do have another Miami drop out off another frame, wondering if I should cut that section out in a C and have it sandwiched welded on top?

Guessing somebody else has fixed a similar drop out, especially Miami...

TIA.
Nick


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## Craig Allen (Aug 3, 2019)

Trying to uncrimp the lower stay maybe more trouble than it's worth as there is one or two pins through the crimped section which ties the dropout to the frame. They would need to be drilled out. Plus the inside of the crimped section is likely filled with brazing which requires a torch to allow it to melt and flow out. Trying to work out the dropout while it is heated up would only result in the stay cracking. 
The bike requires a little surgery but here is how I would fix it.
Take a hacksaw and cut the dropout right down the middle lengthwise where the top and lower stays come together. Cut off the lower stay about 5"-6" from the end. You can get mild steel flat stock at stores like Home Depot to make a new section of dropout. Get or machine a replacement section of steel tubing to match what you have and crimp the end. The new dropout piece can be inserted, brazed with two pins about 2" apart. 1/8" diameter welding rod will make good pins. Make sure your new dropout fits far enough inside the tubing for the pins. Turn down on a lathe a hollowed out bushing about 4" long which should be press fitted into the new tubing. A 3/32" or thereabouts wall thickness should be enough. A press fit is size to size. About 2" of the bushing doesn't need to be press fitted for the lower stay but very snug to allow it to be pushed in. After installing the repaired stay, the dropout can be tig welded at the joint which should be ground to a V angle to maximize the weld. Use four 1/8" diameter pins, two on either side of the lower stay joint and appropriately spaced. The pin holes can be slightly countersunk, brazed on both sides of the tubing and filled down smooth.


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## locomotion (Aug 3, 2019)

there is no easy way to do this correctly/properly to keep the originality and the structural integrity of the frame.
personally, I would first try to uncrimp the lower stay and drill the two pins and melt the brazing, duplicate the broken dropout and do the reverse process to re-install it .... definitely not easy to do, but with careful work, it can be done ... i have done it in the past
then if that doesn't work, I would do exactly what Craig suggested .... also a lot of work and not easy to do perfectly


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## hoofhearted (Aug 3, 2019)

*Finally … re-establish flats … and heat-bend where *
*necessary … placing a resistance beam between*
*same-side dropout legs (where the axel-end would be).*

*….. patric*


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## Nickinator (Aug 3, 2019)

Thank you patric- just what we really wanted to hear! Now, to find a good TIG welder- anyone got a good bicycle savvy person? Got some cool TOC parts/frames to trade! (or cash lol)
Darcie


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## 49autocycledeluxe (Aug 3, 2019)

uncrimping the frame and making a new piece would be the best way. 

other than that cut the bottom part off where the crack is and make a new piece and replace it. no sense in repairing the damaged part


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## Archie Sturmer (Aug 3, 2019)

Maybe also use some wide and strong or thick 3/8" fender washers.


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## Freqman1 (Aug 3, 2019)

So what model Miami you building this time? V/r Shawn


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## Nickinator (Aug 3, 2019)

Another green/black Black Beauty


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## Freqman1 (Aug 4, 2019)

Nickinator said:


> Another green/black Black Beauty



Did you sell the original paint bike? V/r Shawn


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## Nickinator (Aug 4, 2019)

Yes the pristine one went to live in a museum. But, I now have another original paint bike, and not as nice so I can RIDE IT


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## mikey-motorbikey (Aug 4, 2019)

Gday Nick ,I would repair exactly as Patric has described ,trust the Tig cheers Mikey


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## Huguenot (Aug 10, 2019)

A couple of points- first, why repair only the bottom section? The whole dropout looks pretty sketchy, as does the left side one. If it were my bike and intended to be ridden regularly I'd consider replacing both, or at least a complete new right one. Second, a repair (as detailed in the above pics) is almost certainly going to fail. Generally, once a joint has been brazed or soldered a TIG repair becomes problematic. The much softer metals previously used have a lower melting point and will boil, resulting in a weak and usually ugly part. It is almost impossible to remove all the previously deposited material as it will have worked it's way into the pores and pits of the original steel, and the last place you want voids or other weaknesses is in a dropout.
While drilling a "stop hole" at the end of a crack is usually good practice, this is only true if there is enough meat in the part, here it will just add to the problem. 
The heat affected zone (HAZ), while smaller with TIG than other processes, will still encompass that entire section of the dropout. 
In my view the original weld shop you contacted was correct, and most reputable shops would refuse to do the repair as described. 
FWIW, I do both types of repair (welding and brazing) on a regular basis. BTW, "TIG" is nowadays more correctly called GTAW (Gas Tungsten Arc Welding). Guys even older than me still call it Heli-arc, but the gas used most often now is actually Argon, with Helium generally reserved for welding aluminum.
Just my .02, and yes I realize that this may make it cost prohibitive, but those dropouts are pretty basic and should not be too hard to whittle out of a piece of plate with even only a hacksaw and files.


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