Aluminium steerer bonded insert for carbon forks

This is aluminium steerer insert for carbon forks. It can be used for repair of lightly damaged fork steerer or increasing safety on a new fork. Do not even think about using it printed, even from PEEK. You have to have it machined. I do however recommend printing a test piece to check if you can insert it all the way into your fork. There is step file for CNC programming and drawing for machinist in the files.

Editing you own

You will probably need an edit to get correct diameter for your fork to get ~0.2mm side clearance or whatever your epoxy recommends. You also might need different length. Even if you don't know or have any CAD, it is easy in this case. Onshape runs in browser and only needs registration to work with and you will only need to edit sketch 1 dimensions and export the step file and pdf drawing from tabs at the bottom.

Design notes

You can have it made from 6061, it's good enough for this purpose. 7075 is much stronger, costs about the same in the end but is less corrosion resistant, so you should have it anodised. Galvanic corrosion is no joke. Anodising is better in any case and 6061 takes anodising better.

Dimensional accuracy needed for this is relatively low, anybody half competent with a lathe can sucessfully make it to specification.

Having bonding surface Ra12.5 roughness done on a lathe is not ideal but is good enough. Better would be to roughen the surface by hand and then anodise.

Sourcing

Check local machine shops, whenever you are, there are likely few, but are used to dealing with businesses, so you might have to pick up a phone and call. Same with anodising. Or you might use services like pcbway or sendcutsend, which can do both.

Onshape source

Cycling collection

If you are interested in other cycling related items that I have made, have a look at my cycling collection here on Printables.

Support

All my work is free and in the public domain when possible. If you find it valuable, you can support me on Ko-fi.