Modify by replacing parts was one huge reason to buy a CB750 back in the days.
These days seems to be here again. Chopper, racer with complete fairing, half or 1/4, café whatever the parts could make. Dunstall, Rickman, Bimota, Dresda and various tank-sidecover-body makers. Back then people left the stock 4-4 with center stand and stock tank with side covers and lost it, or repainted it with back then funky design. I had to find new 4-4, tank, side stand, all from Yamiya to my avatar bike.
Save the OEM parts so you can turn it back to a stock CB750 which is the condition many want to buy and pay for.
I cut my frame after some thinking.... Frank's frame kit for better service. I have had great help of it. Same bike has now 1005cc, nothing for CB750 purists anyway
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I should not cut the frame on a really good stock bike as delivered from Japan with all small details stock, even all nasty X-screws and no plans at all making more power.
I sometimes see horrible looking CB750 for sale the owner believe is a Café or whatever it can be called. The only one that like it is the builder/owner. Like an ugly child that only the mother like
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Completely different to build a bike with parts from scrapyards only. This is the way to give the parts a second chance. Here no restrictions in my mind since all is scrap metal.
I also understand street fighters. Owning a from the beginning expensive racer, drop the bike so the fairings will be damaged beyond repair. Fairings that cost a huge amount of money. Only thing left is to run the bike naked, modify the bike so it will match like other handle bar, headlights, exhaust etc.
I guess this has made the bike producers to build bikes with that look and the old style bike back again.