I ask myself that question once in a while... These are my thoughts.
Really original bikes, nice original paint frames, bikes in nice complete shape missing only several minor or one or two major components (85- 90% complete) should probably be left original. They sure did a nice job designing and building them years back, and it is nice to preserve some as a record of their glory. Restored bikes are very nice, but I can't ride them without feeling bad about any little nick. I think patina and rust can be beautiful, and really original bikes, complete and with no or little paint left, can often be left as is and be enjoyed thoroughly. In this way they also stand as an example of what the bieks originally were. I think rat-rodding is a very nice way to recycle vintage frames and incomplete bicycles that would otherwise be donors or deteriorate elsewhere slowly due to fear of modifying them and having no current purpose. I mean which is worse- modifying an old cruiser skeleton, or leaving it to deteriorate because you are afraid of modifying it? The modified bicycles can eb beautfiul and are a form of art, and are more enjoyable to me than a show bike- it's nice to look at, but you know it hasn't touched the road usually in quite some time, and will probaably not for some time. (That's not always the case, I'm sure a good few of the restored bikes are ridden by their owners). I think that nothing lasts forever and that eventually (however soon) there will be considerably fewer bikes due to the natural cycle of things. Scrap prices go up and down, nice bikes and rougher bikes alike get scrapped or rot away on farms in woodlands, backyards, etc. To modify the bikes and make them enjoyable in a less traditional way does no disservice to the bike, you may have increased it's life by 50 years. :wink: Many of the changes are reversible anyway- if a bike is ratted then restored down the road, what's the difference? I say just keeping the bikes around, whatever changes done, is great- through the survivor bikes should stand as tributes to genuine styling and perfection and be left either cleaned, restored, or as is. Also, I see no problem with reversible changes like tires, grips, and add ons that make an old bike useable (again, to keep the bike running slightly modified is better than letting it sit in a barn or shed PERFECTLY stock to me)...Even the not-so-reversible changes can be undone by someone with skill and will to do it. I don't really like the idea of ratting cheap repro cruisers made here or in other countries, so if there is no more ratting, build and then rat custom, homebuilt frames.
There's truth to me in both "Bikes are only original once" and in "Bicycles were built for riding".
By the way, I love those Colson clone frames! Those are sweet! I need to start building frames.