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While carrying my road bike via plane one of my front dropouts has been bent slightly so I can't easily install or remove my front wheel. After I inspected the dropouts I found that one of them has closer tips compared to other, so the threaded axle of the front hub doesn't fit the entrance of the slot.

If I file my aluminum fork's dropout until it is the correct size, will that create another problems? If I remember correctly bending aluminum will create more damage than repairing.

Update

I've taken some pics to clarify my situation. In this picture you could see that axle of front hub has already started to abrade the dropout.

Bent fork dropout

Not sure maybe it's my misalignment but looks like the 2 fingers (ears) of the dropout do not looks perfectly parallel.

Bent fork dropout

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    Are you saying that the fingers of the drop out were pushed closer together, but not bent sideways? A photo would really help us understand what's going on here. Nov 5 '19 at 15:13
  • Do you have any claim on the airline for luggage damage ?
    – Criggie
    Nov 6 '19 at 8:29
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    @Criggie unfortunately no, because i have to report any damage or problem inside the area that you take the luggage.
    – Efe Can
    Nov 6 '19 at 10:14
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    @Torben the fingers got pinched together because the end of the drop out was hit, if the plastic spacer was in place it would have transferred the force to the top of the dropout which is designed for such forces. Crushing the fork as you describe would not produce the damage described in the question.
    – Rider_X
    Nov 8 '19 at 16:06
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    @Torben You suggested plastic spacer would be insufficient for this type of damage, but I disagree. The plastic is solid and sticks out well beyond the ends of the drop out fingers. You would need to crush back to, and beyond, the tip of the fingers to start bending the tips of the dropout as described in the question. Otherwise the impact force will be transferred to the portion of the dropout that supports the axle weight, thereby saving the tip of the dropout. The plastic spacer serves a dual role.
    – Rider_X
    Nov 8 '19 at 20:46
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It looks like the front finger of the dropout suffered an impact that pushed it backwards. Compare it to the undamaged dropout to see how much it was moved.

Impacts that bend metal tend to mess up the paint. Is there a big mark on the front surface?

You could widen the slot by carefully filing away a small amount of material. That is not going to weaken the dropout significantly. The question is whether the front finger is weakened by being bent.

My instinct is that it is OK, because the deformation is small, and the major forces on the front wheel are up and rearwards.

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If an aluminum fork dropout has been bent, it has already been compromised in strength. Bending it back will make matters worse. Filing it wider open will also make matters worse, even if it was not already bent: thinner metal can obviously carry less load.

I would say don't risk it and find a replacement fork instead. A fork failure when riding can cost you teeth or worse if you crash.

For the future, to prevent bending dropouts/forks/chainstays when transporting bicycle, it is recommended to insert "dummy" hubs when wheels are removed and to fasten them with your wheel axles. This way, any strike to the frame is more likely to be deflected and won't cause a permanent deformation. Of course, having a wheel axle in place would also help dropouts to survive as it will back them up.

A dummy hub can be just a piece of wood wide enough to fit between rear/front dropouts and with a hole big enough for the axle. Or it can be indeed an old hub without rim/spokes/etc.

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    There are also "dog bones" which are a plastic bit that comes in drop outs shipped from manufacturers on new bikes. Bike shops throw many of them away but usually keep quite a few laying around; I'd ask at your LBS for a set. In general there are a lot of cheap plastic pieces included in a shipped bike that get thrown away (hub end protectors, etc). Most shops are happy to hand them out to customers. Nov 5 '19 at 14:33
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    @DeletedUser Right, I just recently held one of those plastic bits in my hands. Even meant to mention them in the answer but got distracted and forgot… Those are a viable solution, although I would rather go with something else. These plastic spacers do not sit in the dropouts very tight compared to e.g. locked QR-skewers; still better than a thin air. Nov 5 '19 at 17:05
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    True, but also depends on the QR. Many of the ones I have do nothing because they are only meant for compression and have no means of decompressing (keeping the fork legs from being crushed closer together). I actually have and use a set of long threaded "bolts" (they have no heads) that have four wing nuts and washers each. The wing nuts lock against each other and support the fork against movement in either direction (crushing or pulling forces). They can created with parts from a hardware store inexpensively, but the free dogbones are usually good for a use or two, before they "wear out". Nov 6 '19 at 15:28
  • @DeletedUser The plastic dog bones do not protect from this kind of damage. They are way too flimsy to withstand the forces involved here and the fit isn't close enough to keep the dropout from bending. They only protect the fork legs from bending. A dummy hub or just an axle with nuts on both sides of the dropout with nuts tightened properly will help, though.
    – Torben
    Nov 8 '19 at 11:44
  • @Torben We'll just have to disagree. The manufacturers use them for a reason. While they vary in dimension, I've seen several varieties that fit so tight they need to be "popped" out with a rubber mallet upon arrival. Nov 11 '19 at 19:22

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