Why is it that cafe racer builders typically seem to prefer to use SOHC engines as opposed to DOHC...I am referring basically to Honda CB750's here.?
gls1320
A couple of reasons. The SOHC4 is a pretty iconic bike to begin with, plus it was an exceedlingly popular bike with a very long production run and a tremendous aftermarket in the 70s which was the hey day of cafe racer bikes in america.
Also size plays an important role, a sock four is physically closer in size to other big bikes of the era like the triumph bonneville and harly sportster. There were a lot of parts that could be easily modified to fit the cb750 sohc from a triumph or the like (bodywork mostly). Where as the dohc bike is a physically larger bike with a huge tank, massive seat, and just supersized all around. They also had a short production run of 4 years (9 for the sohc). Also the f models were the real performance dohc bikes and were already styled after cafe racer trends of the 70s (the bodywork looks like a tracy body).
Also size plays an important role, a sock four is physically closer in size to other big bikes of the era like the triumph bonneville and harly sportster. There were a lot of parts that could be easily modified to fit the cb750 sohc from a triumph or the like (bodywork mostly). Where as the dohc bike is a physically larger bike with a huge tank, massive seat, and just supersized all around. They also had a short production run of 4 years (9 for the sohc). Also the f models were the real performance dohc bikes and were already styled after cafe racer trends of the 70s (the bodywork looks like a tracy body).
Good question and you will get a varity of answers. My position on it is that most people that want to be "Cafe Racers" are ignorant, fashionista, poseurs who don't have a clue about why cafe bikes exist, where they came from and that form follows function. Therefore, they believe that in order to be cool they have to start with a CB750 SOHC, so they can buy all the requisite bits from Carby, Benji, et. al. That along with clubmans, bum stop seat, checkers and an Ace decal are what make you a true cafe racer. Then if you have to live the cafe lifestyle, you can pop for some engineer boots, rocker jacket and a Davida helmet. Then you have it all.
The DOHC Honda does not lend itself as well to the traditional cafe look due to the frame/ seat shape and wheel selection. Many will suggest that it is difficult if not impossible and prohibitively expensive and machine shop intensive to put spoke wheels on a DOHC. (They are very wrong, by the way.) However, the DOHC CB does make a very nice 70's Superbike, which is the way I would go anyway. I think it could be the new cafe look and carries the same exact principles into a new decade.
Ken
The DOHC Honda does not lend itself as well to the traditional cafe look due to the frame/ seat shape and wheel selection. Many will suggest that it is difficult if not impossible and prohibitively expensive and machine shop intensive to put spoke wheels on a DOHC. (They are very wrong, by the way.) However, the DOHC CB does make a very nice 70's Superbike, which is the way I would go anyway. I think it could be the new cafe look and carries the same exact principles into a new decade.
Ken
I like the DOHC motors - they make more HP and you can make'em into something nice. The real nice thing is you can pick up a really nice bike for cheap money. I wouldn't mind having one in my garage but I'd lean to the 1100f but the 750 would also be nice. I agree with the above - you could make a real nice 70's superbike out of the 750. I'll still will have my SOHC bikes in the garage but will be looking for a DOHC sometime in the future.
Justin,
Thanks for filling out your bio. Is this English? 4 doesn't = for, etc. This is a forum, not a text. I would suggest if you don;y have the time and patience to type out a full word, you might not have the time or patience to work on a bike.
Tracy has been out of business for a while and I don't think they made a body for the DOHC 750.
Ken
Sorry for text typing I was in a rush plus I'm using my iPod touch to send this out.
I figured as long as it could be understood then it would be fine but I was wrong.
I noticed your signature says newbies hate you, why do you take pride in this?
Unless u were born with a bike your where once a "newbie". So why is it that now that your a veteran you seem proud of the fact that you can be a jerk persay
I figured as long as it could be understood then it would be fine but I was wrong.
I noticed your signature says newbies hate you, why do you take pride in this?
Unless u were born with a bike your where once a "newbie". So why is it that now that your a veteran you seem proud of the fact that you can be a jerk persay
easy does it Justin, you had it right the first time. Ken is no jerk and he will assist you in any way he can, but he places a premium on clear and concise communication. He does not suffer fools and will not waste time with people who are inconsiderate or lazy. More often than not, the stuff in peoples' tag lines are inside jokes so don't get all worked. check out the search function as you begin to formalize your project ideas, tons of info in there. good luck. cheers, bcr
From another perspective, the SOHC 4's came along at the end of the Cafe era in the UK. They almost fitted because they were styled in the same way as Brit bikes. DOHC, as Ken suggested, were in the US Superbike era which interestingly enough is a more popular look in the UK.
That 80's era of Freddie Spencer, Wes Cooley, Steady Eddie etc was all about a muscle bike look that many people today like - it's sort of like muscle cars. You could build a nice fast freddie replica from a DOHC quite cost effectively or go mad and add modern suspension and still have a sweet ride that looks good.
That 80's era of Freddie Spencer, Wes Cooley, Steady Eddie etc was all about a muscle bike look that many people today like - it's sort of like muscle cars. You could build a nice fast freddie replica from a DOHC quite cost effectively or go mad and add modern suspension and still have a sweet ride that looks good.
Justin,
The first thing I do when starting a project is to figure out what the bike wants to be and then take it from there and make a plan. Since you are starting with a DOHC K, there are going to be some limits on what you can do as far as bolt up pieces go and what is going to require modification. Since you are asking about Tracy bodies, is that the look you are going for? If so you can probably make a Tracy body from some other model fit, with some work. I suspect Geeto67 has some knowledge in that area, maybe even a body. What do you want to do for wheels, brakes and suspension? Are you more interested in a 70's cafe or an 80's superbike? What are you planning on using the bike for, every day commuter, fun around ton bike or sport riding in the mountains of Indianapolis?
Make a plan and go from there. If you ask specific questions you will get specific answers.Just about anything can be done, it just a question as to whether it is going to be easy, hard, expensive or a combination. Does the bike run well now? What does it need?
It doesn't matter to me much one way or the other how newbies feel about me, it isn't a point of pride, just a statement of fact. Once they start liking me, they're not newbies anymore. Texy only hates me when I drink his last beer or take his last smoke!
Ken
The first thing I do when starting a project is to figure out what the bike wants to be and then take it from there and make a plan. Since you are starting with a DOHC K, there are going to be some limits on what you can do as far as bolt up pieces go and what is going to require modification. Since you are asking about Tracy bodies, is that the look you are going for? If so you can probably make a Tracy body from some other model fit, with some work. I suspect Geeto67 has some knowledge in that area, maybe even a body. What do you want to do for wheels, brakes and suspension? Are you more interested in a 70's cafe or an 80's superbike? What are you planning on using the bike for, every day commuter, fun around ton bike or sport riding in the mountains of Indianapolis?
Make a plan and go from there. If you ask specific questions you will get specific answers.Just about anything can be done, it just a question as to whether it is going to be easy, hard, expensive or a combination. Does the bike run well now? What does it need?
It doesn't matter to me much one way or the other how newbies feel about me, it isn't a point of pride, just a statement of fact. Once they start liking me, they're not newbies anymore. Texy only hates me when I drink his last beer or take his last smoke!
Ken
Many years ago I had a tracy body and ended up selling it. I should have kept it but I really didn't like the way it sat on my bike (SOHC). It didn't hold much gas and really didn't fit the bike very good without some modification - ok that was then and now they are cool to have - go figure. (I knew I should have kept the one I had...)
I guess my point - figure out how your going to ride your bike (trips or just bar hopping) and build from that perspective. I don't see any reason why you couldn't have a nice bike using a DOHC bike - certainly the price is right on them right now...
I guess my point - figure out how your going to ride your bike (trips or just bar hopping) and build from that perspective. I don't see any reason why you couldn't have a nice bike using a DOHC bike - certainly the price is right on them right now...
Ken is a school teacher (principal actually). He places a value on grammur and spellink. Me thinks.
If you are handy with fiberglass and making giant molds, the DOHC cb750Fs were designed to look like a tracy body. I imagine someone could make a full size mold of all the bodywork mounted on the bike and then using the mold lay up a handlaid version of a one piece body.
Tracy (I forget the guy's first name) also went by the Fiberglass works and did make one piece bodies for the DOHC cb750F bikes. I have never seen one for a K bike but they are pretty universal in mounting. They are exceedingly rare, and really the only place I have ever seen them is on drag bikes (which still use one piece bodies).
this place could probably make you one as they have the molds for most of the cb750F stuff:
http://www.beasleycomposites.com
you could also adapt a ZRX drag body (airtech and a few others make them).
If you are handy with fiberglass and making giant molds, the DOHC cb750Fs were designed to look like a tracy body. I imagine someone could make a full size mold of all the bodywork mounted on the bike and then using the mold lay up a handlaid version of a one piece body.
Tracy (I forget the guy's first name) also went by the Fiberglass works and did make one piece bodies for the DOHC cb750F bikes. I have never seen one for a K bike but they are pretty universal in mounting. They are exceedingly rare, and really the only place I have ever seen them is on drag bikes (which still use one piece bodies).
this place could probably make you one as they have the molds for most of the cb750F stuff:
http://www.beasleycomposites.com
you could also adapt a ZRX drag body (airtech and a few others make them).
The performance mod I made to mine was to replace the motor with a CB900 donk and fit CBX pistons to that, but that was a long time ago and the old memory is getting vague.
This was my CB900 which came with a CB750 motor in it - just before I sold it.
http://pinkpossum.com/cb900/cb900a.jpg
This one I "borrowed" http://pinkpossum.com/cb900/streetfighter.jpg
This one I just googled
http://2.bp.blogspot.com/_o_oFOw6JO..._oFOw6JOHo/SuRSb4OYF5I/AAAAAAAABNA/Y19is4__9iQ/s1600-h/HONDA+CB750F+SPENCER.jpg
How much performance are you looking for? IS a pipe and jet kit enough or do you want larger bores, big cams porting, Titanium valves etc. It helps to develop a clear vision of where you want to go. It makes it much easier to work out teh directions.
This was my CB900 which came with a CB750 motor in it - just before I sold it.
http://pinkpossum.com/cb900/cb900a.jpg
This one I "borrowed" http://pinkpossum.com/cb900/streetfighter.jpg
This one I just googled
http://2.bp.blogspot.com/_o_oFOw6JO..._oFOw6JOHo/SuRSb4OYF5I/AAAAAAAABNA/Y19is4__9iQ/s1600-h/HONDA+CB750F+SPENCER.jpg
How much performance are you looking for? IS a pipe and jet kit enough or do you want larger bores, big cams porting, Titanium valves etc. It helps to develop a clear vision of where you want to go. It makes it much easier to work out teh directions.
First of all, you want to start with a better motor. GS1150 motor in a (pre 85) Katana chassis will give you more performance in stock trim than emptying your wallet trying to blow up a DOHC CB.
Seriously - go to a drag strip and look at what they're running. I'll buy you a beer if you can see a competitive DOHC CB there.....
Oh dear. I'm not sure I'd go that far with one of those motors unless you go the rest of the way with Carillo rods as well. As Hillsy mentioned there are better places to start if you want the absolute max HP out of it. Mildly tuned, no worries, but balls to the wall could end in pain (to the wallet).
Certainly the 16 valve Suzie can make a truck load of HP. I'm not sure either goes around corners though....
Certainly the 16 valve Suzie can make a truck load of HP. I'm not sure either goes around corners though....
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