I happen to have some longer spokes from a 21 inch wheel, but need to replace a couple bad ones on the front wheel of the TT truck.
My weird question is, can the long ones be chucked up on a wood lathe and turned down so the rim ends fit? I know you can probably buy new ones, but I'm interested in experimenting. Are there original center points to be found on the base and taper end?
TT and T front wheels are the same wheels. No difference.
In the case of these spokes at least, the answer to your question is no.
"I happen to have some longer spokes from a 21 inch wheel"
If he means longer from a 23" wheel, Why couldn't he turn them down to fit a 21" wheel? He will have to hold them absolutely centered.
I should have said the answer to the second question is no. I haven't used a wood lathe, but I suspect the answer to the first may be yes.
Of course you can. Wood is wood and a spoke is a spoke. Dimensions are critical for a tight fit as is centering for a true wheel.
In and ideal world yes there might be centering points left indented in the wood. If you had a tenon cutter that would be easier then chucking up in a lathe.
Tenon cutters, I believe, do not leave a radius at the shoulder of the spoke, where it meets the tenon. This transition really should not be a sharp corner.
I did a search after I posted this and found some old discussions where one member chuck them up in a wood lathe using a 4 jaw chuck on the hub end and a tapered drill chuck on the tenon end. It looks like he did a great job!
If he's out there, do you have any others cut down for the TT front rim you want to sell?