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Discussion Starter · #1 ·
New member, first cafe racer build.

I've been build bikes, painting, fabricating and other bike related stuff for a long time. I've ALWAYS wanted to build one of these but never pulled the trigger. I got my paws on a 73 CB750 and it's a peach! Rough but fairly solid. I'm missing some parts here and I'm excited to start hunting. For the most part, I plan to keep it stock but will lose the stock fenders, signals and seat. Plan on making my own duck tail and seat and massaging the tank to the infamous cafe style. Then paint of course. Here is a link to the closest thing I can find to what it will look like:

http://silodrome.com/wp-content/uploads/2012/10/honda-cb750-cafe-racer.jpg

1. I'm looking for what tires everyone is running on these (matched size for front and back would be great - pick looks like avons)
2. Any leads on a better front caliper setup (prefer using stock spoke wheels)
3. Good service manual.

The engine had some water mixed with the oil so I need to crack the case and see what's going on in there. Any suggestions are welcome - this will be fun and will make this Michigan winter a little more fun!

Thanks everyone!

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does the bike turn over? cb750s are psuedo dry sump and air cooled so you are likely looking at condensation in the pan (unless you fished it out of a lake). If it spins free, don't bother "cracking" the cases, just *** the block and try to get it to run. CB750s make oil pressure like a car so usually the guts are pretty good.

the most expensive part of any cb750 is an engine rebuild.

metzler lazertech me33. Love them. Avon roadriders are also good. I have both and I love them.

1975-76 GL1000 gold wing front end uses the same steering stem as a SOHC cb750 and is a direct bolt on at the triple trees. You get dual single puck calipers, an alloy DID 19" front spoke rim, and 37mm forks and a wider stance. The forks are slightly taller so you will need to address that. it's the best brake upgrade you are going to get, there is literally no other brake upgrade for sock fours unless you are willing to machine a bracket to use an airheart/grimeca
 

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Discussion Starter · #3 ·
Thanks for the great info. I'll start poking around for the front end. Really wanted to keep stock but braking is important and a single piston just won't do.

About the engine...it doesn't kick over. The kicker will move to the point of addressing the internals but then hits a wall. I don't want to have to crack the case so I can pull the side covers to see what the hold up is. The bike is now broken down completely and the engine is on my workbench waiting for me to start on it. Blasting and powercoating will fill the tie gaps for now. The carbs need rebuilt kits and I've got crud in the intake passages - so the top end is coming off for sure. Rings (maybe), gaskets and a head cleaning is in order. I'd prefer the lower end stay intact but we'll see what I find. A good service manual would be great so if you know of one - that'd be great!

Again, appreciate the feedback. Keep it coming :)
 

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either stuck valve or rust in the cylinders. poking your pecker at the bottom end isn't going to tell you much. Pull the valve cover and pull the head first. If you really feel you need to have a look at the bottom you can turn the mill upside down and remove the bottom case have.

you can convert the stock forks to dual disc but let me tell you, 35mm forks holding up 500lbs of motorcycle isn't that great. You could spend for cartridge emulators and new springs but for $200-$300 more you could have thicker fork tubes and a wider stance.

only use honda factory parts for the carbs. hondaparts-direct.com is your friend. Usually you only need the gaskets, o-rings, and maybe the float needle.
 

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GL front end swap is the way to go.
join the sohc4 forum and poke around for some writing of "Hondaman". Has a great list of simple upgrades that actually make a positive difference.
thinking about paint and seats with a none functioning bike is stupid at best.

- - - Updated - - -

Running no fenders is also stupid.
tearing a bike apart right off the back is....yup....stupid.
 

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Have fun with the build, enjoy the process, don't get frustrated, take advice but in the end build what makes you happy. I'm on my third build with another one in the wings that is going to require major surgery. I'm in Michigan as well so if you need an extra hand sometime more the happy to help. I'm working on a stock CB750 K0 and a CB350 for my wife that is going to be really sweet.
 

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Discussion Starter · #9 ·
either stuck valve or rust in the cylinders. poking your pecker at the bottom end isn't going to tell you much. Pull the valve cover and pull the head first. If you really feel you need to have a look at the bottom you can turn the mill upside down and remove the bottom case have.
Noted...I think your theory of a stuck valve is right on. The bike sat outside leaned up against a barn for many year and some Einstein left the oil lines unhooked and out as rain-catchers (hence the water in crankcase). I'm very anxious to pull the top end off and get it cleaned up!

you can convert the stock forks to dual disc but let me tell you, 35mm forks holding up 500lbs of motorcycle isn't that great. You could spend for cartridge emulators and new springs but for $200-$300 more you could have thicker fork tubes and a wider stance.
Even though I'd like to stay with the original parts as much as possible - I can't ignore the technology and safety advances. I will be looking at your suggestion.

only use honda factory parts for the carbs. hondaparts-direct.com is your friend. Usually you only need the gaskets, o-rings, and maybe the float needle.
Agreed!
 

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Discussion Starter · #10 ·
Have fun with the build, enjoy the process, don't get frustrated, take advice but in the end build what makes you happy. I'm on my third build with another one in the wings that is going to require major surgery. I'm in Michigan as well so if you need an extra hand sometime more the happy to help. I'm working on a stock CB750 K0 and a CB350 for my wife that is going to be really sweet.
Will do. I may just contact you over the winter! I've got a ton of little stuff to do which will keep me busy. Getting the frame powder coated is going to be the big leap toward the finish. Everything else falls after that :)
 

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Discussion Starter · #11 ·
You must like going to the gas station often. :p
Ha! Not to worry - I won't be taking this on long trips. I'm sure it's not going to fun on the back. This will be the 'nice weather' bike. I've been a bit spoiled with a full dresser ;)
 

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Discussion Starter · #13 ·
still Please don't bang any dents on the tank.
Ah, the second to comment. It kind of goes with that retro cafe racer look. Granted, there is not real benefit except the obvious look and the challenge of my fabrication skills.

Why is that :) Is there a reason not to?
 

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It serves no real purpose for a street bike other than cosmetics and negatively affects fuel quantity.
 

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Discussion Starter · #15 ·
Any of you guys that have been commenting have pics of your bike(s)? I'd like to see some of the suggestions in action (er in color atleast).
 

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Ah, the second to comment. It kind of goes with that retro cafe racer look. Granted, there is not real benefit except the obvious look and the challenge of my fabrication skills.

Why is that :) Is there a reason not to?

a) you ruin a perfectly good meal cb750 tank. Go price out an undented replacement and tell me if you think it is a wise idea.
b) you add weight. nobody is that good that a little body filler isn't required.
c) you reduce your capacity by a gallon or more.
d) you don't get any extra room for your knees, you just change the place where your leg squeezes the bike.

The reason for knee dents in the old days was so that a 5 gal fuel tank could be fitted, and when you go bigger you need to make room. Why 5 gal? at one point it was necessary for for bigger bikes to carry that much fuel to complete their circuits around the isle of man.

the tank you like is available here, and I believe it is 5 gallons:
Cafe Racer Gas Tanks, Motorcycle Gas tank

STOP talking about style. These aren't choppers, style doesn't dictate the bike. Functionality does. If you build the bike with function in mind it will come outlooking the way you want it to anyway, if you try to force yourself upon it you will have a bike that only you like the look of and even you don't like riding.

Stupid cafe kids with no concept of motorcycles except that they want them to look old started this trend of bashing knee dents into stock tanks. At this point it has become a pretty clear indicator that the person building the bike has no fucking clue what they are doing and the bike is probably built poorly. Same with clubman bars on a cb750 with stock pegs, It indicates a lack of real thought. What's even dumber is the look they are trying to emulate are really brit bikes where the rubber knee pads fell out due to poor build quality.
 

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usually banging dents in a tank ends up shit.

as for cosmetics. there s google. that DCC cb 750 look you going after uses a custom tank. but you already knew that.

anyway :) good luck with it and welcome aboard.
 

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this is what a real cb750 race bike looks like:




this is what a Rickman Cr750 looks like:


this is the best resource for cb750 performance stuff you will ever find:

Satanic Mechanic

these are all better inspirations for you than that medicore DCC bike. That was a bike built to sell newbies shitty parts they don't know better not to buy.
The bikes above were built to run

since you keep talking about keeping it "stock", I suggest you look at this:
Classic Cycle City Gallery - Honda CB750 SOHC K1 (1971)

it's a nice stocker with some period style updates using new parts (seat, repop bar end signals, superbike bar, cut down mirrors).
 

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Rickman CR750 is the sex.
 

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Discussion Starter · #20 ·
You guys are great. I see nothing but passion and lack of toleration for the group of cake decorators that plague most forums about bikes. I get that more than most but really, it's about what people want and riding is riding. I'm hope that hasn't changed - however, having said that, my purpose in posting was to hear all the comments so I take no offense to any of it and bring it on so long as your tasteful and creative.

I have never had one of these and always thought they'd be a blast to ride! I'm not the biggest fan of crotch rockets and maybe that's from the idiots I see riding them. These cafe racer bikes have balls, history and raw style. Not something I'd take on long trips but riding around the area, riding to work, small day trips with friends...bam, it's the ticket.

What I envision is a bike that looks like the era-specific bike that it is. I prefer to use era-specific parts (as much as possible) but I had though about using some of the technology enhancements (maybe better pipes, brakes and lighting). All of you have enough background to help me to determine what's shit and what's THE shit.

I wanted the knee dents because I though it was done to squeeze the tank more for control (like motocross) and now that I know the real reason - that seems like a crock of shit. You saved me a ton of work there!

You also touched on bars...I had thought the clubman style bars were what everyone used to use back then. What is the era-specific choice for that?

I'm going with the stripped down look of no fenders and I'd like to stabilize the front forks. Any thoughts on what was used for that back then?

Look forward to hearing back!
 
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