LOL yes Nicko' I always have a plan
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I've always liked to take older bikes and "modernise them" (been doing it for 30 years now). Luckily, I started my adult life as a structural engineer, designing bridges and cranes, before I got side-tracked into other stuff, so I'm confident in tackling bike geometry.
But, it's pretty easy for the VF - swapping the front for a 17" and going for a lower profile "modern" radial tyre, makes a difference of about 1.5mm (larger) in the outside diameter of the tyre, but as I'm changing the forks and yokes, I can work with the position of the fork legs in the yokes to get the top of the steering head bearing at exactly the same height above ground as the original set up. I'll measure the fork offset from the stem when I'm choosing the right year of CBR 600 (or maybe VFR 750) forks. I'd be happy with a slightly lower offset distance to shorten the wheelbase a tad (there's a bit of room to work with before the wheel hits the radiator).
At the rear, switching to a 170/60 x 17 radial tyre will drop the tyre outside diameter by about 15mm, so I can change the new shock length, or adjust the top mount to compensate for that easily enough.
I'm planning on keeping the standard swinging arm and don't want to alter the overall "look" of the bike. I'm definitely with 'Trimmer as regards to modern "cafe racers" and "street fighters". My preference is to improve function over form and to leave bikes looking as though they'd come from the factory the way I build them.
It wasn't always the case though - back in the early '80's I also went for more radical, but still restrained, changes in appearance - take, for example this 1973 CB500F that was my first real "frame" job - I designed a monoshock conversion for it based around a Spax shocker for a 350 LC, using newer Honda "Reverse Comstar" wheels and a CX 500 twin disc front end. This helped us put on much wider tyres front and rear, which altogether got rid of the +100mph weave that had previously afflicted the bike from new. Adding in a 550F1 tank, a Kawasaki Z650 tailpiece and seat, CB 550 K 4 into 4 pipes, CB900 switchgear and throttle and lots of other changes with new paint resulted in this, when "sit up and beg" was the style (street-fighter, before street-fighter) to go for.
A couple of years later, we went for the sportier approach, put on CB650 carbs, a Yoshimura big bore kit, customer fabricated Kerker replica 4 into 1 exhaust and fitted the CB650 rearset footrest plates and some ace bars. That was a really sweet bike, will try and hunt out a photo.
I'm definitely a fan of the more "subtle" approach rather than the TAT that's spouted as Cafe/Fighter today.