Installation of both Gen I Kool Caps, and Gen II Kool caps is very simple on 20 inch wheels.
Both generations of Kool Caps are completely plug and play now. They can be installed without any modifications to the 20 inch wheels.
With the current generations of Kool Caps,
Installation onto the wheels could not be simpler.
Simply use pure 100% silicone adhesive.
Choose whatever color you want. I prefer clear, as it can be used on just about anything else you might need it for, without worrying about color match. Available at local hardware stores everywhere.
Silicone absorbs shock. Remains flexible. And will never come loose under any riding conditions.
Shown below in clear. This was labeled as "Aquarium adhesive". It really is what they glue together glass aquariums with. And, if you can trust that your glass aquarium won't split open, and, spill 100's of gallons of water in your house (at 8 pounds per gallon). It will certainly hold Kool Caps in place.
You can also use other flexible adhesives. Such as, Silicone RTV (Which stands for; Room Temperature Vulcanization). However, most rubberized sealants are designed for very specific duties. Often with stuff you don't need, or want in them. If is says; "100% Pure Silicone Adhesive" on it. Use it.
It does not take much. Strategically placed to prevent as much unsightly squeeze out as possible. Just gently squeeze them into the silicone. Wipe off any excess with alcohol. Align them carefully. And, let them dry overnight.
And that is it. They are never coming back off. Unless you want them to. In which case, a fresh sharp razor blade. And, some time, care, and, patience, will allow you to remove them. Presumably, from a damaged wheel, to be reinstalled on another set of wheels. Frankly, I can't think of any other reasons to take them back off. To an "Old Schooler", what now lies happily hidden underneath, is like a gnarly bear trap pedal scar. It is just not something that we ever really want to think about. And, certainly not something we want to uncover, and re-expose! Although showing a friend for something to cringe at, is plausible. It is overwhelmingly best left hidden. And, forgotten!
And, Voila! Much Better!
Shown below is one of the very first original hand machined sets. With polished rivets. ...Polished, just because I can.
And, you can too, if you want to!
Original Gen I installation. And the not so simple adaptation to 24" inch wheels soon to come below.