Ok... lets say someone did decide to go with a spoke wheel instead of the stock comstar but also did a drilled dual disc conversion with steel braided lines. Wouldn't this set up be close to the performance of the stock F3?
For the record I am getting sick of this whole cafe argument. I say build what you want to build and call it whatever you want to call it. Its your money. You bought the bike hopefully with a vision in your head of what you wanted it to be. Go for it. Now I can get back to my "wannabe" cafe build.
No a cb750 spoke-d wheel with twin drilled discs and braided lines will closer to the f3 setup than stock but still not as good. Why?
well first of all, drilled holes in the disc do not increase performance, if anything it is a very slight almost negligible decrease because you are reducing surface area. What the holes actually do is keep the pads clean and help the disc cool. The thinner the disc the more cooling you need which is part of the reason you see a lot of modern sportbikes with them. However the earlier thick discs do not really have major heat issues because they are very thick....which brings me to my next point.
The things that will have a an effect on brakeing are the rotors, the calipers, and the wheel. Regarding the rotors it is their diameter, mass, and surface area that has the most effect. The earlier rotors are stainless steel, not the hardened steel like the f3 and more modern bikes use. You never see a 69-76 with a rusty front disc because of this. Stainless steel is traditionally a softer metal than ordinary steel and is more likely to change its shape when heated, which is also why the disc is so thick. Having such a thick disc gives the rotor a lot of mass, and one thing hopefully you remember about physics class is that the more mass something has the more effort it takes it change its direction. Overall the 77-78 rotors are a better material and lighter.
As for the calipers, well the f3 calipers were originally designed for the goldwing back when they were naked bikes as well as the upcoming redesigned cb750F which was delayed in making it to production, it is a caliper rated to stop a much heavier bike that it was placed into service on. It is still a single puck caliper so it has similar limitations as the 69-76 calipers, but it is a slightly more efficient design.
The braided lines are the only thing you mentioned that actually increases performance of a braking system. Under high pressure that comes with pulling the brake lever hard you get line flex from the rubber. The rubber actually stretches and gives up some of its pressure. A braided line does not flex nearly as much and maintains a more consistent pressure. this will help your dual disc setup and is highly recommended for any brake setup you use.
The diameter and mass of the wheel play an important role in braking as well. The smaller the diameter of the wheel the less effort it is going to take it to stop (provided mass does not increase the smaller you go). cb750F and K wheels are about the same size and use the same tire so this really isn't an issue, but while the comstar bare may weigh slightly more than a spoke-d wheel bare, the full setup of wheel and rotors is much heavier for the spoke-d rim than for the comstar. also where that mass is on the wheel has an effect, the closer it is to the center the less leverage it has to fight changing direction. Comstars have better weight distribution as the majority if its weight is closer in, whereas the spoke-d rims have a pretty even weight distribution.
the other factors which are in your control are tires, brake pad coumpund, etc....and these really have to be appropriately selected for their application. Run a modern spotrbike slice of rubber on the front and your braking will improve because traction is improved, but you give up all weather capibility and longevity. Same with race pads, build some heat and you can outstop a lot, but cold out of the gate and you may not be able to easily stop your bike.
HOnestly the best spoked wheel setup that is a pure bolt on for a cb750 is a 75-77 goldwing front end. You need everything from the trees to the tire to bolt it on a cb750, but you get better calipers, better rotors and a lighter front wheel (the gl1000 uses the same alloy rim that the hondamatics do). Yes the front end gets heavier because of the bigger forks, but overall your braking power is increased.
now about you sick of it bull....well that is tough. One of the ways in which I think the internet is diluting our hobby is it gives way too many people access to information that they don't respect. In the pre-internet days of bike building you had to hang around in shops and with people that lived that life, and they would impart the common philosophy of their aspect of the hobby. You don't philosophy with a couple of picture, money, and a burning desire to impress people with your custom bike. The old way, you learned why people did certain things to bikes and built it a certain way, you picked up what you felt you needed and left what you didn't but always you had an appreciation for what was going on because it was tangible and not pixel. The internet does not make you earn your stripes and develop a true appreciation for what is going on here, it just attracts snotty kids who say "I am going to do what I want" and ignore sage advice in a way that in the old system would have caused someone to knock yer block off.
When you use the term cafe racer it comes with expectations and a philosophy. When you talk about your bike and things that go against this philosophy and people point it out you seem to throw this little temper tantrum. In the old days this kind of $#!+ would cause whomever was helping you to walk away and let you figure it out on your own, which would be considered earning your stripes the hard way. Now with the internet you don't learn that lesson because there is no shortage of people to help you, so you loose the ability to really appreciate what is actually going on in the hobby.
A true cafe racer is built around one thing, riding experience. it is not the image crap they sell you in magazines, not the fashion of it, merely owning the bike that looks like maybe it belongs does not make you part of the hobby or culture, nor does it give you real appreciation of machinery. You want to be stubborn about it be stubborn about it but don't be surprised if people out there feel that you are pissing on their hobby. Don't be surprised if the people who know bikes get a chuckle from your cobbled together cafe pouser bike, after all you didn't build it to impress them, you built it to impress people like your self, people who don't appreciate bikes other than whether it looks really cool.
to be honest I have this conversation with local newbies in my neighborhood at least twice a week. you think you are sick of it.......
