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Hi,

I'd value your opinion.

Picture is the drop out of a friend's Colnago EPS. It looks to me that there is damage to the frame beyond paint cracking. It could have been caused by having the bike on a stationary trainer.

Anyway, what's your view? The first, inside shot (if you can zoom in) appears to show deeper-than-paint cracking. If it is structural, can it be repaired? He'll take to to a bike store but wanted some other opinions to help with the diagnosis.


C Bicycle part Iron Metal Composite material Steel Bicycle part Spoke Bicycle drivetrain part Bicycle chain Gear Bicycle part Bicycle accessory White Black Carbon
 

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Looks like it's toast.

Generally speaking, frames are not designed to take the point loading experienced when the rear drop outs are forced to take the loads associated with being restricted/captured (on a trainer).

Using any high end frame on a trainer is a questionable practice. Better to use rollers or an indoor specific bike or buy disposable used bikes for trainers.
 

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Agree that is a former bike frame.I would email Colnago or Calfee, see if they could fix it.
 

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Picture is the drop out of a friend's Colnago EPS.
Roasted, toasted, and burnt to a crisp. A repair might be possible. Contact Calfee or other repair companies.

Whether this was due to being used in trainer is a very open question. A rider who really rocks the bike and has a very solid trainer might be the cause or it might just be coincidence. Many argue that trainers don't impose much of a burden on a frame while others (as evidenced here) say that trainers and lightweight frames don't mix. The jury appears to be out on that question.
 

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The dropout is definitely toast. As noted above, your best bet is to have the manufacturer repair or replace it. Its possible to repair weld the bracket but at a minimum you would need to identify the drop out material specification, the material specification for the chain stays and the material used to join the two together. This would allow a good welder to select the proper filler materials and weld process. Also you would assume all risks if everything went south. If the adjoining stays are carbon, its most likely a wall hanger.
 

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Is there a machine screw head buried under the paint on the outside of the dropout? Also, does it look like the hole on the inside of the dropout is threaded and can you see if there is a machine screw threaded in from the outside in?

It looks like the chainstay fixing point is fixed while the seatstay fixing point is adjustable, making it useable in different sized frames. A machine screw would hold it in position once adjusted to the frame size.

If there is no warranty on the frame and there is a screw in there and the frame is not rideable, you can try to clear the paint out of the screw head and tighten it down. If the screw is striped it can be removed and the dropout threads could be recut and a new bolt put in. If push came to shove the hole could probably be drilled up a size and threaded for a size larger bolt.

I had an unpainted dropout start to separate like this and tightened up the machine screw and all was good. I continued to ride the bike and the screw never loosened again.
 

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Yes, I think there's a machine screw through there, which is pretty common on rear dropouts. (The same dropout would work with different frame sizes that make different angles at the dropout.)

I'd strip the paint on the whole dropout, then see what it looks like. Perhaps it's repairable. Good luck!
 

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if steel, just take it to the most reputable frame builder near you.
 

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It could be fixed.

What's broken here is either the metal plug/connector in the seat stay or the drop out itself. Yes, it is screwed together. No, I'm willing to wager that none of those metal parts (drop out, plug) are steel. So put away your welding torches, folks.

It looks like it was bent from being put in a stationary trainer. No, that isn't the smartest thing to do with a high end bike with either alloy or carbon drop outs. Yes, it does happen. To me it looks like the bike was torqued over to one side, and the connection between the trainer and the bike put a sideways pressure on the dropout/seat stay that it was not designed for. It looks like the dropout torqued so the seat stay was pushed inward, toward the center of the bike.

If you are REALLY LUCKY all that has happened is that your friend bent the drop out tab and the screw. Show this to someone who can bump metal (professionally, not your brother-in-law who works on bikes as a hobby) and maybe they can tease it back into shape. Maybe. Chances are, however, is that even if it is just bent you still have a compromised piece; it may be an overstatement but generally aluminum castings (which is what this appears to be) don't like to be bent, even once.

Based on the picture, though, it looks to me like it fractured the tab on the drop out itself. You aren't going to be able to weld that tab back together if it has fractured - the drop out is bonded to the carbon chain stay and you will eff things up if you put heat on it. Plus who knows what kind of alloy that is made from.

Most likely scenario for getting this fixed is to call guys at either Calfee or Ruckus. Ruckus does exactly this kind of work.

Any Bike. Any Dropout. | News & Tech | Ruckus Composites
 

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I had a problem quite like this a few years ago on my Colnago EPS. I was able to get it fixed through Ruckus Composites in Oregon. They made a new dropout from carbon plate. The repair has been excellent!

Ron
 
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