Anyone know if the captive nuts, similar to the above are available separately? They are similar, but don't have the spikes on them.
I have contacted the UK distributor, but no luck.
Seems crazy that a £250 pair of shoes are deemed useless because the threads are not replaceable.
Sidi sells a slight variant on them that works fine and most substantial Sidi dealers have them. If they don't, they can get them for you.
The ones with the prongs are really only for when you're doing a major repositioning of your cleats and your original holes simply are in the wrong place. They need a lot of midsole to hook into, and your midsole is usually cut out where your current cleat mounting holes are located -- all you have there is the carbon fiber of the sole, which doesn't take much to sharp prongs. Those are actually hardware made for woodworking projects. The correct ones are the ones with the flat lands, not the prongs.
The bolts are really spread out for Look-pattern cleats. For SPD and for SPDR cleats, it's one stamped plate with both holes on the one plate. You don't use the individual threaded studs for anything but Look, and even for Look there are some shoe manufacturers who make a larger plate that holds everyone together. They aren't better -- probably faster when someone is building the shoe but after that, use the studs.
When you install them, you may have to trim around them a little with a knife so they fit neatly in the midsole. Be sure they sit square and don't project up into the foot compartment at all, nor project past the bottom surface of the carbon fiber sole. (Shoe makers made these fittings originally when you had deep fiber or leather soles and they still haven't figured out that better fittings are needed.) I use some marine epoxy caulk around the stud to hold it in place.