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Discussion Starter #1
I've been looking for something to occupy my spare time this winter and have talked the wife into letting me take up some more garage space.

I've taken an intrest in the Cafe Racer style of bikes and have been shopping for a mid 70's CB750 since that seems to be a popular option and fairly easy to find. Today I came across an 81 CB750F Supersport running w/ title at an excelent price. I haven't seen much mention of any CB750 outside of the 70's being used aside from one on this site which was an 1980.

My question is this. Is this bike a good starting platform? From what I'm finding not much changed over the years with the CBs so I'm assuming I'm good to go.

Any input would be great. Anything special I need to look out for?
 

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The 1970's CB750's have a single overhead cam engine(SOHC). The 1980's on have a dual overhead cam engine. The 1969-1978 CB750's represent a motorcycle that many say killed the British cycle industry -- it was an amazing production bike for its day "so amazing it was... almost boring." The later DOHC CB750's are just as good (probably even better) as the early bikes, but not even 1/2 as popular.

If you have what it takes, almost any bike can be built into a cool cafe bike. The question is not, "would such or such a bike bake a good platform for a cafe....?" The right question is "do I have what it takes to build a unique bike that does not follow the popular mold?"

However, the 1980's CB750s are great bikes. They are fast, reliable, safe and relatively fun to ride, and I've see a good handful of both cool and crappy cafe racers out of them. When it boils down to it, it is all about you.

In my humble opinion most of the best cafe bikes are built from older bikes -- 1979 and older bikes generally are out of the club.

peace and grease
-fang

'70 Suzuki T350
Download The Fang.mp3 HERE
 

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Hi Brian,
Welcome to the board. It is very helpful if you FILL OUT YOUR BIO!!!!
That way we may know a little more about your interests, current bikes and abilities. That way we an more fully answer your questions.

That being said I will assume that you know which end of a wrench o use and can do minor modifications. The DOHC Honda 750F is a good bike, but the aftermarket for cafe is more limited than for the SOHC.

What do you want the end product to look like? Old school cafe, i.e. clip-ons, alloy or glass tank, bumstop seat, megaphone exhaust. Can be done but you will need to make everything fit. 80's period superbike; 18" wheels, 4-1 exhaust, clip-ons, oil cooler, cut down seat, rearsets and individual air filters. Most parts are more available.

Are you sure you want a 750? It is easier and sometimes more practical to go with a smaller bike for a first cafe effort. Honda 125, 350, 450. Yamaha RD 125, 250,350 or 400. XS 400 or 650. Kawasaki KZ400 KZ650. Lots of really good choices depending on what you want to do.

We really need more info from you and about you if you want more than just general answers.

Ken

P.S. Have you filled out your Bio yet?

AHRMA 412
Vintage racing - old guys on old bikes
 

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Hi Brian,
Welcome to the board. It is very helpful if you FILL OUT YOUR BIO!!!!
That way we may know a little more about your interests, current bikes and abilities. That way we an more fully answer your questions.

That being said I will assume that you know which end of a wrench o use and can do minor modifications. The DOHC Honda 750F is a good bike, but the aftermarket for cafe is more limited than for the SOHC.

What do you want the end product to look like? Old school cafe, i.e. clip-ons, alloy or glass tank, bumstop seat, megaphone exhaust. Can be done but you will need to make everything fit. 80's period superbike; 18" wheels, 4-1 exhaust, clip-ons, oil cooler, cut down seat, rearsets and individual air filters. Most parts are more available.

Are you sure you want a 750? It is easier and sometimes more practical to go with a smaller bike for a first cafe effort. Honda 125, 350, 450. Yamaha RD 125, 250,350 or 400. XS 400 or 650. Kawasaki KZ400 KZ650. Lots of really good choices depending on what you want to do.

We really need more info from you and about you if you want more than just general answers.

Ken

P.S. Have you filled out your Bio yet?

AHRMA 412
Vintage racing - old guys on old bikes
 

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hi, and welcome to the forum. i figured i'd add a little of my own experience to help; or prevent u from making any of my own mistakes. i purchased the same bike u are looking at for far less than what u'd get any old sportbike or japanese cruiser. it ran, but had little issues and seemed like i could turn it into a nice honda gb500/ average cafe bike look a like. boy after seeing and researching what i would need to buy and fabricate myself i could have bought a nice slightly used gb500 or very similar bike.... and that was w/ out paint, tires, and other items. i went the o.g route and had it built and painted like the normal 750ss dohc. it seemed like the wise thing to do to the bike considering that to cafe it would have been almost double the freshened up price. (and parts are all over, if all u do is "freshen up" a bike). so my honest opinion would follow many of the other members here. get something that u like the way it is and would like if u customized it on a small budget. that bike will make u happier than trying to turn "chicken shit into chicken salad" (exact quote from bike builder when i said i'd like to turn my 750ss into a gb500 look a like!!!!)kinda like the chopper to cafe mistake my bud has!
p.s. my rule of thumb is only customize to the same price a nice original version would bring. has saved me on quite a few "barn fresh" money pits! but if u really want to go w/ the 750ss i have a complete set of plastics and tank if u want them.

03 rsv Tuono (STARF8R)
75 cl360 ("Chupa"thingy)
2000 Ninja 250r ("chibi")
 

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Discussion Starter #6
Ok profile filled in some.

I'm fairly decent with a wrench and have access to those who are even better. I also have some experience laying glass and have access to a fairly complete machine shop when needed. I can weld if my life doesn't depend on the finished product but again plenty of resources who can get the job done a lot better when needed.

I was thinking of heading in the direction of one of the following two but of course with my own twist.

http://www.caferacer.net/hwoldhuis_cb750.html
http://www.caferacer.net/anacondahonda.html

Working towards these examples gives me a target. I can get more creative as I go finding out what works and what doesn't.

To answer so of your other questions about the bike...

I think I'm definitely headed for a bump stop seat. If I go with the 81 I'd have to lose the rear tail section and fab up a seat and bump which I was either planning on doing in fiberglass or carbon.

Up front I'm still undecided on using either clip ons or clubmans I like the look both ways and would have to sit on it to decide what I thought felt better.

My questions where more frame related. Will the '81 frame give me the same lines that I'm looking for? Close to the two links above. For some reason the 81 looks quite a bit taller than the photos above but it could all be a matter of perspective. That and the fact that the 81 I'm looking at has a full front fairing. Do you guys normally lower the bikes in the process of Cafe'n them out? Or is this just "camera magic".

The exhaust currently on the bike is 2-1 on each side I think I’d like to take that to a 4-1 if possible but that’s not really a big deal for me.

Basically the mechanical I can deal with the fab I can deal with but I want to make sure I'm not fighting an uphill battle from the get go. If the attitude of an 81 frame is gonna fight me the whole way I'll keep looking but for the price of this bike if I can make it work I need to get on it.







Edited by - Brian on Nov 24 2007 6:04:27 PM
 

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Brian,
Based what you have given as examples, I think you can do it on the 81 frame. The bad news is you ill need to get a different tank to go with the kind of seat you are going to make. You should check on the stuff from Glass from the Past. Brett can probably tell you what can be made to fit the DOHC frame.
Here are the important parts to me.
1. I think the stock headlight can work and look very good
2. The stock guages need to be replaced with some more traditional looking ones.
3. Clipons
4. Alloy front fender and 18" front wheel
5. Good rear shocks
6. some sort of rear fender nd license plate bracket.

Good luck and have fun

Ken

AHRMA 412
Vintage racing - old guys on old bikes
 

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Discussion Starter #8
Thanks. I'm a little worried since I got conflicting posts there but since the guy is almost paying me to get the bike out of his garage, A running bike w/ clear title for $250, I think I'm gonna go ahead and pick it up tomorrow afternoon. I'll get it going and post up a thread in the projects forum. Even if I get into it and decide it’s not the best bike to start with I should be able to get more than my money back out of it.

I was already planning to hammer out a custom tank so that’s not a big deal. Granted this will be my first foray into sheet metal so I may check out the company you mentioned just to see. I just don't know how I feel about fiberglass tanks on the street. Shit happens and I'd rather not be on fire when it does. I'll have to do a little research there. Everything else you mentioned I think I can grab from the local scrap yards and the internet.

Having fun is what I'm after. Even if it is a complete bust it will keep me busy for a while and I'm sure I'll learn a lot.

quote:
Brian,
Based what you have given as examples, I think you can do it on the 81 frame. The bad news is you ill need to get a different tank to go with the kind of seat you are going to make. You should check on the stuff from Glass from the Past. Brett can probably tell you what can be made to fit the DOHC frame.
Here are the important parts to me.
1. I think the stock headlight can work and look very good
2. The stock guages need to be replaced with some more traditional looking ones.
3. Clipons
4. Alloy front fender and 18" front wheel
5. Good rear shocks
6. some sort of rear fender nd license plate bracket.

Good luck and have fun

Ken

AHRMA 412
Vintage racing - old guys on old bikes
 

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Good luck with the tank. It is Pretty ambitious, but if you want a project this should keep you busy. $250 is too good of a price to pass up.

Ken

AHRMA 412
Vintage racing - old guys on old bikes
 

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brian,

you realize that in both of the pictures you posted that was a CB750 sohc, right? frame is different, engine is obviously different......

look at catboy's build closely, cause that is where you will be heading.

b-t-w, $250 is a STEAL. worse case is that you flip it and buy a CB750sohc!

texy

p.s.- if you want to list your town in missouri on your profile, i promise not to come there and kill you. oh yeah and welcome to the board!

http://groups.google.com/group/PhillyVinMoto
 

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Discussion Starter #13
Yes I realized this I was just giving those examples as the direciton I wanted to head in. I wanted to make sure the 81 frame had the same flat backbone.

After doing a bit more research I think I can make this happen. Picking the bike up tomarrow night after work. And like you said if all else fails I can flip it and get an mid 70's like I started out looking for.

-Brian

quote:
brian,

you realize that in both of the pictures you posted that was a CB750 sohc, right? frame is different, engine is obviously different......

look at catboy's build closely, cause that is where you will be heading.

b-t-w, $250 is a STEAL. worse case is that you flip it and buy a CB750sohc!

texy

p.s.- if you want to list your town in missouri on your profile, i promise not to come there and kill you. oh yeah and welcome to the board!

http://groups.google.com/group/PhillyVinMoto
 

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Discussion Starter #14
Ok so I picked the bike up last night and got it moved to it's new home. With much delight my wife exclaimed "What the fuck is that ugly ass piece of shit." So it has begun. I now own what my wife considers an eyesore, no forward thinking from that woman.

I'm gonna start tearing her, the bike not the wife, down this week and clean her up as I go. I'm not sure if any one here is interested but I'll be putting some stuff up on ebay including the front fairing, rear tail section, sissy bar and a few other stock parts that I don't think I'll be needing.

Also as a bonus I got a spare motor for free that the previous owners mechanic purchased for parts last summer. I haven't seen it yet but from what I hear it’s mostly complete and has compression.

I think I made out pretty good on my $250 investment. Hopefully here in a couple of weeks I'll have some amount of real progress to show and will start a thread in the project build forums.

Thanks for all the input so far I plan to become fairly active here and hope to make some good acquaintances. And on a side note I can already see what the general ambiance is here. I've got some thick skin so say what you want. If I don't like it I'll tell ya to kiss my ass after I shit and we can move on.

-Brian


Edited by - brian on Nov 27 2007 08:48:53 AM
 

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Please post pics of the bike as is so we can see the dramatic changes you do. It's really cool to see the transformation(and hard work) people do to their bikes.

I know we here and on other similar boards know what goes into building projects like this. Some folks just don't understand the passion,sweat and yes BLOOD that goes into a bike that may even be worth LESS than a restored original. That of course isn't why we build these and other projects that are uh..lets just say different from the norm.
 

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Brian,

if you have the sidecovers with all the tabs I can save you the ebay fee.

Since the big differences between the SOHC and DOHCs have been discussed I am just going to thow my 2 cents into it:

here is a great resource for DOHC cb750s: www.cb1100f.net

download your honda factory manual from there.

honda made a 900f and an 1100f variant, and may big bore kits are still available for the 750s, 900s, and 1100s. An 1100 motor will not fit easily into a 750 frame but a 900 kinda does (as long as you use either the 750 or 900 mounts).

by now you probably have figured out that the DOHC do not have that straight across backbone you were looking for. The DOHC F bike frames are not the same as any of the other cb750 frames. For starters they are thicker tubing than a K or C. Also they have a lot of different mounts for stuff that the Ks and Cs don't have like rear disc brakes.

Those bikes are part of what I call factory cafe racer styling. The bodywork on the DOHC was modeled after tracy offerings and HRC race bike bodywork for the SOHC bikes. The bodywork on the bike is meant to look one piece but is actually 4 pieces (by now I hope you have figured out that only the 1100Fs came from honda with a fairing although there was an option for one). These bikes are the link in the evolutionary chain to factories building race replicas.

There are actually two different versions of cafe styling: the 1950's to the late 1970s, which is more that small humpty back seat, big tank, british look, and the late 70's early eighties cafe racer look of square fairings, whale tails, underbelly pans, and 4 into 1 exhausts. This DOHC 750 fits more into that later category, as does the gpz900, the gs1100es and early katana, and the yamaha FZs. IT is kinda hard to make the later bikes look like the erlier style but that is ok, I think you can embrace the later style and still have something cool.

If you want to see what a difference a year makes, consider these two cafe racers from my stable. The first is a 1978 SOHC 750F, the second is a 1979 DOHC 750F:





huge evolutionary jump there isn't it.

By now you have probably figured out that aside from tires you can't use SOHC parts on a DOHC. This is important because there are way more speed parts and way fewer body parts for the DOHC and vice versa. In Japan there is a retardedly big following for both bikes and there will be stuff for both that you absolutley can't get here. Surf around the DOHC cb site I posted above there is a primer on how to get cool parts out of japan when you don't know anybody.

one trick I have seen is some guys used to shave the whale tail off and fiberglass the rear section into a squareback tail, looks really unique and somewhat older. Also another advantage you have is that you bike can use the gold boomerang comstar wheels off the canadian cb1100F (the front is the same as a cx500 turbo also) which is probably the best comstar made. You may also be able to use the cb1100F wheels which are an improvement over the stock comstars. However, spoke wheels are going to be a big problem for you so I hope you are not considering it. Also another good upgrade is the 1982 cb750F/900F brakes which were converted to twin piston calipers. They are a bolt on deal, work much better than the single pucks, and are still used today on other bikes.

anyway, good luck and post some pics.
 

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i think Geeto is sick today. that post lacked any sign of sarcasm. i know i learned a lot though!
say, what is the skinny on that fuel tank you got on that F model? its the bees knees!

'72 cb750
'75 cb750
'76 cb750
 

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Discussion Starter #18
Yeah tell me about it. I haven't been around here that long but I've read enough to know how it is. I really expected alot more out of everyone.

It is good information however and appreciated.

-Brian

quote:
i think Geeto is sick today. that post lacked any sign of sarcasm. i know i learned a lot though!
say, what is the skinny on that fuel tank you got on that F model? its the bees knees!

'72 cb750
'75 cb750
'76 cb750
 

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been busy with....life, sarcasm put on hold.

The tank on the 78F is a dunstall fiberglass tank. It came from Huey at 6th street specials. I didn't built the '78, I bought it like that from a regular at bar matchless. However because he parked it outside all the time it had corrosion and some of the seals were on the verge of going bad. Next time I take a pic of it she will look a little different (if I ever get around to putting her back together). I actually have another dunstall tank and plan on using that on another project, thanks to the internet they are not hard to find anymore and they are even being repoped in aussie land. However, Brian forget about putting it on your bike, she doesn't fit without looking goofy.

Brian...."expected more out of everyone"? not exactly the thing to say. There are enough great motorcycle minds here that if you have a specific question you can ask it. We are not going to build your bike for you, but we can help as much as possible. If you use the search function you will find that DOHC bikes have been discussed as cafe fodder before and there is plenty of info.

Personally, it sounds like you just went with what was cheap and not really what you wanted. If it were me I would clean up the DOHC to the point where it was running well and halfway presentible, then sell it to finance you buying a SOHC.

BTW, the first things you should check on any DOHC are the starter clutch (the come loose all the time), the timing chain, and the valve adjustments (it is bucket and shim). without a sound engine you don't have a sound cafe racer.

troll around the cb1100f.net site for a while. There is some amazing stuff there.
 

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geets
i too am missing your sarcasm. i like your sohc rig...has the cafe look i understand (through my old eyes). spoked wheels would finish off the package nicely...not there is any thing wrong with mag wheels. "wheels make the bike" that's what i say. high-flage alloy a personal fav. that being said, long tank/short seat combo is also a pre-requisite. hand beat aluminium tanks (no paint) (with dents for the clubmans) (ha) have most cred but there are tons of super fibreglass tanks out there that are great and some really cool shapes and paint-jobs become possible with that option.
-parks
ps sick chopper
 
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