Which model to choose and does it matter? Please HELP

[PhilipKattrup]

Hi fellow Honda CB750 enthusiasts

Help!!

I am thinking about buying a Honda CB750 as a cafe racer project. However as i started to do some research i quickly found out that there exists many different models, both SOHC (1969.1978) and DOHC (1979-2003). My question is:
- What model should i choose if a want to build a nice cafe racer?
- Can all the models be turned into the same identical cafe racer, meaning that it does not matter which model to choose?
- And lastly how many KM is acceptable for an second-hand CB750?

I hope you can help me with some good answers

I found a picture of a model from 1969 which i really like but, this model is over my budget, maybe i can make some of the other cb750 models look like the same:



 

[shinyribs]

SOHC frames are much easier to cafe. DOHC tanks , side panels and frame rail shapes are difficult to modify without  somewhat extensive metalwork.

Mileage on a CB is sort of a moot point. There are 100k mile bikes still running strong and 5k mile bikes that are seized solid. It really all depends on how responsibly they were stored.

SOHC bikes all pretty much share the same frame. The K is the standard and the F is the SuperSport. The F will have a mount for the rear disc brake master cylinder and a swingarm to accommodate the rear disc brake. Everything else is the same. The standard rear drum is a much better brake IMO. There are slight differences yet, but that's pretty much the gist of it. 77-78 F's are rumored to have valve guide wear issues, but otherwise all of the SOHC engines are basically the same. F's have a slightly hotter cam profile, but the hp ratings of all years and models are within a few numbers of each other. SOHC bikes are nearly bullet proof in every area, especially the charging system.

DOHC K's and F's are basically that same story as the SOHC's. Slight differences to accommodate the F having a rear disc. The DOHC C-model however is an animal all it's own. Shaft drive rear wheel and a 10 speed transmission ( standard 5 spd gearbox with a HI-LO range splitter). They have their own unique, and totally oddball, frame and tinwork. DOHC engines have pretty darn good bottom end power compared to SOHC bikes. They also have the reputation of a slightly more fragile charging system that isn't exactly cheap to replace.

You also have a much better chance of finding a bike with spoked rims if it's a SOHC. But stock SOHC brakes kinda suck and the front disc squeals no matter what you ever do with it. The SOHC rear drum is fantastic though. I mean, really a great brake. And SOHC carbs are much easier and MUCH cheaper to rebuild. Front and rear suspension bits between all models ( SOHC & DOHC) are pretty much equal, other than the C model having air-assisted forks. Which can be defeated and returned to ''normal''.

That's all I can think of off the top of my head...

[TOOLS1]

shinyribs wrote

 The DOHC C-model however is an animal all it's own. Shaft drive rear wheel and a 10 speed transmission ( standard 5 spd gearbox with a HI-LO range splitter). They have their own unique, and totally oddball, frame and tinwork.

That is just the 900. The 750 uses the same engine, trans, frame, and hub as the "K" and "F" model.
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[PhilipKattrup]

Thank you for your answer! Helps a lot

[Truck]

The 900C transmission is a huge waist, I've shifted maybe twice with the hi-low. If you want the power of the 900 go with an F.

[Re-run]

I would ass that the basic shape of the sohc lends itself to cafe looks better than the dohc does. However, the 77/78 have different tanks, so take that into consideration.

I do have to say I like the sohc rear drum. It works very well with good feel. I do not have issues with the front squealing though. I used a few tricks that work for me. Slotted the pad, chamferred the sides of the pad, make sure the plastic ring is between the piston and pad. I rarely have any squeal now. On a rare occasion, but I get it with my 06 yamaha every so often too. A very high temp grease can be used on the sides of the metal part of the pad, that slides between the rubber seal. High temp as in it keeps its shape at like 500+ F, so it does not run. Pad composition makes a difference, too.

Mileage, as Shiny says, it depends. However, a maintained CB can hit 100,000 miles(160,000K) before major work. However, you are also looking at age. Age makes gaskets and seals fail. So, if the engine has never had those replaced, good chance you will be doing it in the near future. Doesn't mean there is a problem though.