I want my cycle wings to be secure, to not have visible bolts, and to be detachable...

The plan is to get 4 x flat steel bar about as long as the wing is wide and (say) 10 mm wide, then weld some studs to them (say 2-3 per bar). Then bond the bar to the wing using sikaflex, and then simply bolt the wing onto the brackets.

In theory this should be just as secure as bonding them straight onto the brackets, but will mean they are easily removable without exposing the bolt heads. The twisting force of doing up / undoing the nuts won't damage the sikaflex because the studs will be located by the bracket they are bolted through so won't be able to turn, being all welded into a single piece.

Has anyone tried this?

I glassed 4 Bighead studs onto each cycle wing which is similar to what you are saying.
One thing I'd do different is to glass nuts next time.

Having the studs pointing towards each other slightly (because of the radius of the wing) means you have to bend the two arms of the stay together to get them off.

Maybe sikaflex would be easier as the bar you are talking about would flex and allow you to get the wing off. On the other hand it may break the PU after a number of removals.

I'd tap the bar or weld some nuts on, so you unbolt from the underneath...

Had my studs been PUd on, I'm sure they'd have come off by now, due to the frexing reason above.

Paul.

Just glue them on.

Just use sikaflex. Sticks like poo to a shovel

I araldited my wings on to the flat bar, and left them in position overnight to go off
Next day whipped the whole lot off the car and layed fiberglass sheet over the bar, thus sandwiching the metal bar between fiberglass

7500 miles later, there still attached, with no problems YET

Steve

Enough detail?

Cheers!