Although it looks good enough to me, I have exactly zero experience in this! The tool maker at work (where I am doing the work) would be more than happy to use something this close but I am not sure if I am.

Gap can get paper through, I would say its no more than 0.2mm at most but can’t seem to find anywhere to suggest what the tolerances are supposed to be.

Any help and advice would be appreciated.

P.s. I know the work bench is a mess, and that is a rear wheel knuckle for a old shape focus – nothing to do with bikes I am afraid.

How are you making the joints?

Fillet brazed, not confident with TIG.

paging Ben Cooper….Ben Cooper to the forum please.

Ideally it should be a perfect fit, obviously.

How much of the diameter of the tube end is in contact with the dropout?

Obviously, hard to tell if I am honest.

If you can get a piece of paper, or feeler tip etc, in then rotate it fully around the joint to see if it closes up anywhere.

Or shine a torch up the other end of the tube with the lights off.

Even if you are not confident with TIG, could you get two or three small tacks on to make sure the position is maintained and then braze over the top?

It definitely closes up using a piece of paper, its a perfect mitre, just not in perfect alignment I think. Yes the TIG TAC seems like the best idea I’ve heard so far..

The minimum number of tacks that will resist shrinkage/distortion. You will also need to ensure the gaps are then clean of welding gas residue to ensure flow into the void.

That’s fine – especially if you’re fillet brazing. Dropouts like that are usually sold as TIG dropouts, but as long as you can lay a decent fillet you’ll still get a plenty strong enough joint.

And a clean workbench is the sign of a dangerously organised mind 😉

There you go, decision made.

What are you building?

Not my work bench is the issue here ben, honest!

Neil, the build is a hopefully time proof steel (obviously) XL 29er. 44mm diameter 120mm long head tube, 3 sets of bottle bosses, 142×12 rear drop out, rear triangle geometry as such; 450 chain stay w/ 73.5deg seat angle, 55mm BB drop. 70 deg head angle with a 490ATC measurement (for rigid forks with a external Hope H cup), will also run a 100mm fork up there at some point. Will also have a 630mm ETT with ~540mm seat tube. I could link you to previous posts or to blog spam but I’ll save you the boredom 😆

edit: and a standard threaded BB shell, none of this press fit rubbish.

Sounds good, hope it all comes together nicely.
I’ll do a search and be keen to see the end results.