Drops too narrow to fit axle

Vintage Carlton frame VS. lovely new Zenith hubs.

As the picture hopefully shows I've just found out that the axle of my new hubs cannot be easily fitted into the drops of my vintage frame. Same problem on the rear. I presume the workaround is to use some sort of tool and widen the drops. However, if I go ahead just trying to widen them without seeking advice I will almost certainly fuck things up by failing to make the drops exactly equal on each side hence making the wheel position slightly out of line. I haven't at this point tried to force them in, if I do they might just fit but the thread will be ruined for sure.

So dear experienced forum members, is there a know and valued work around for this? Searching the forum I found no direct information but some reference to drilling (?) out drops on vintage bikes to make them deeper. How? With what tools? How to avoid fucking it up?

Search coldset.

How much are they too small by?

I'd just (if it is not much) slot the axle in, steel is quite a tolerant material.

Surely it's made for a 9mm axle track hub? File it anyway.

thanks, but it's not about coldsetting the thing. it's definitely the right width that way.

yeah measured it just now. it's pretty much 9mm or perhaps only a minuscule amount less. I tried with a bit of force and the threading just started getting damaged. using force is bad no?

yeah, file it a bit perhaps? just thinking I could make matters worse....

Sorry reading fail on my part.

And mine! Just assumed that it was the distance between the two dropouts that was the issue.

You can either a) swap to a 9mm axle if it is a 10mm, or b) file the dropout.

I'd go with b personally- you will be able to do it very accurately if you are carefull.

Just file one side of each dropout, checking against a known reference point (i.e. axle) as you go.

file the axle not the dropout!

Which would be cheaper here- wheel/hub or fork?

I've filed both before.
The axle is quicker, if you do it right there's no issue whatsoever.
In fact it's standard keirin proceedure. (at least thats what the bloke at Kalavinka said)
The dropouts can be a right arse to do.

however when filing the axle you must make sure both sides are equally filed.
(i.e. flat on two sides at each end)

file the axle not the dropout!

Listen to eyebrows !

File two flats on the axle - don't touch the drop outs.

Out of interest, why?

I'd lay into the dropouts with a 10mm round file, as it'd more or less be self-centreing.

Saying that you'll have your work cut out if it is chromed, which is what it looks like.

I'd use a flat file to take off as little material from the inside rear of both dropouts until the axle just goes in. This way there'll be no alignment problems. Chrome poses no problem, a sharp file will go through in one pass. I'd use a round file to finish the curve nicely.

Although.. If you file the axle you can swap front wheels back to a smaller axle with no problems.

file whichever you think will not last the longest, good luck!

I'd have guessed filing axle was easiest?

Easy to replace, and the threads will work with flats on them, same as threaded steerer with a slot in it.
Also much easier to hold an axle still in a vice, than whole bike or forks.

I'd go with what Richard Cheese said about filing with a round file, will make sure you get it even on both sides of the dropout then.
If you dont have a file you could drill the dropouts, as this would also be self centreing. Just have to be careful not to drill too far up and take out more of the frame then you intended to.

NO!
File the axle.
Its simple.
Dropout steel is fucking hard stuff.
Axle metal is not.
Get a flat file, file two flat sections onto the axle, and it will go in just perfectly.

Basically, you are not going to damage either the dropout or the axle.
The point is, you will get pissed off when filing the dropout as it takes you an 1/2 hour to get through .5mm of material.

Listen to the brows.
Some Suzue hubs come with axles with flats.
Save the frame!

if u file the drops you could cause misalignment. Not an issue on a swivel fork but, the drops are not made to be smaller either, so u cold cause a weakness, and u dont want that.

some track axles come with flat sides for this exact problem.

File the axel.

My choice would be to file the axel. If you do this, it is a good idea to screw a bolt back and forth over the patch that you are filling, occasionally. This prevents too much metal building up in the threads either side of the filed patch.

Yeah - I had the same issue (and possibly the same forks by the look of it)

Just took a file to the drops - a long one so that I could file both sides at the same time thus keeping the drops symmetrical. Took about 30mins or so - most of that was offering up the axle to see if I had gone far enough.

My thoughts being that the forks that came with my frame aren't original and aren't as nice as my campy hub :)