9mm hub axles don't fit 9mm dropouts?

[DWF]

I'm having a small issue that I have not encountered before. On my '96 Bianchi with a Columbus Genius fork with 9mm dropouts, my two Campagnolo hubs from the same era fit and swap easily. In fact you can see clearance in the photos (first two hubs in photos). I wanted to drop in a different front wheel to experiment with tire clearance and ran into a problem fitting a White Industries Mi5 9mm front hub (last hub in photos) and a Campagnolo hub holding Zonda rims. Both axles got stuck less than 1/4 of the way into the dropout. I don't have a great caliper to measure the opening, but an eyeball on a mm ruler looks like 8.8mm

I've never had this issue before swapping out front rims on 9mm dropouts and wondered if this is a common occurrence, that not every front dropout and axle is exactly 9mm.

Of course, I also would like to know how to fix this issue. Would taking a fine tooth flat file carefully onto the inner dropout surface be OK? Or is it better left to a machine shop or framebuilder?

Any help with this is appreciated.

[robt57]

Been there, filed that... I've both filed dropouts, and made flats on the QR axle where I did not want to file thru chrome on fork.

[Gabe77]

Leave it! This is way better than lawyer lips. You can easily spread the fork to install wheels.

[oldpotatoe]

Originally Posted by Gabe77

Leave it! This is way better than lawyer lips. You can easily spread the fork to install wheels.

Not a fork dropout alignment issue/width/spacing but the chromed dropout at the entrance is a wee bit small for the WI hub..A few passes with a good file and the WI hub will drop right in..as has been mentioned above.

[DWF]

Thanks everyone! I’ll put a file to it this weekend.

[Broccoli Cog]

The WI hubs are notorious for doing this. I had the same experience. Shimano hub fit fine but the WI MI5 wouldn't go all the way in. This was on the rear dropout though for me. I took a file to the inside of the dropout and all is well.

[Peter P.]

Chrome is incredibly hard. You may find filing the dropout an exercise in futility.

Your best bet is to find hubs that fit and stick with them.