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dcmsideshow
12-21-2011, 7:47 PM
Howdy all.

I currently have a 1980 Honda CB750K that I am hoping to make into a cafe racer. I am thinking about buying a seat from cb750cafe.com (here's a link to the seat I want: http://cb750cafe.com/parts.php?id=60), but I have a problem first.

Here is a picture of the frame:

http://www.flickr.com/photos/dcavallari/6516152913/in/photostream

If you look closely, you'll notice two things:

--first, the guy who owned it before me cut out a section of the frame that I will need to re-weld back into place.

--second, unlike older cb's, the frame isn't flat on the top, thereby accommodating a flat seat. It kind of curves upward at the rear.

My question is, will I need to chop this and flatten it all out to make the seat I want work?

LuckyJones
12-21-2011, 10:47 PM
It'd probably be simpler to just bend a new loop and weld it in so it's flat. Since part of the frame is already cut out, you might just want to build yourself the flat section to better match the frame in the pic from the cafe site.

hawtpocket
12-21-2011, 11:23 PM
the pictures on the side show it fitted to a DOHC like you have, so you might email and ask how he did it.

swinewerx
12-21-2011, 11:51 PM
What I see is, that you have a dual over head cam frame and motor, the ones on that guy's site are single over head cam frames and motors, way different altogether, unless he has a section for dual over head cam framed seats and such, if he does then you could go that way, otherwise, a whole make over of that frame you have would need to be done. I obviously have not owned a dohc 750 before, I only have sohc 750s, and have made everyone of them rigids! I have yet to see a rigid that is a cafe as well!! Maybe you will be the first to do this? If so, keep us updated with photos of this journey!!!Please!!!

Hooligan80
12-22-2011, 1:03 AM
What I see is, that you have a dual over head cam frame and motor, the ones on that guy's site are single over head cam frames and motors, way different altogether, unless he has a section for dual over head cam framed seats and such, if he does then you could go that way, otherwise, a whole make over of that frame you have would need to be done. I obviously have not owned a dohc 750 before, I only have sohc 750s, and have made everyone of them rigids! I have yet to see a rigid that is a cafe as well!! Maybe you will be the first to do this? If so, keep us updated with photos of this journey!!!Please!!!

I have seen plenty of DOHC CB750 rigids, as wells as a few cafes abnd brat style bikes.

HWC
12-22-2011, 7:50 AM
yep chris barber built a cool lookin rigid cafe awhile back....ill dig u up some pics

on your seat question ,,youll hav to make/adjust the mounts to make the seat fit flat an level an the rear part will cover the back part of your frame,,heres one i did a couple years ago, with one of carpys seat sections..

http://s135.photobucket.com/albums/q157/hillbilly750/750%20cafe%20tracker/


heres chris's cafe

http://crossbreedcycles.co.uk/CafeC.aspx

bparsel
12-22-2011, 8:09 AM
I did this same thing to a DOHC. I won a seat on ebay for a SOHC that Carpy had made. Instead of changing the frame etc I used the seatpan from the DOHC and modified it a bit. Took everything off the SOHC pan and made it fit the DOHC seatpan. Worked out great and solved all of my bolting issues.

dcmsideshow
12-22-2011, 8:30 AM
Cool, so it is possible to just gut the seat and take out the seat pan, then modify? If that works, I think that would probably be the easiest route. How much modification are we talking here? what came on the seat from Carpy? Did you have to tear much of that apart?

bparsel
12-22-2011, 8:42 AM
Cool, so it is possible to just gut the seat and take out the seat pan, then modify? If that works, I think that would probably be the easiest route. How much modification are we talking here? what came on the seat from Carpy? Did you have to tear much of that apart?

Really no modifications other than re-working some bracketry. HOWEVER, I just took a closer look and it appears he is doing something a little differently with his seatpans now......possibly molding them completely himself out of fiberglass. The seat I got from him was back in '06 and was based off a stock SOHC seat pan so it made the swap pretty easy to a DOHC pan. You need to find out if the pan and tail are all molded together into one piece or not.

I would say email him and ask first, you wont be the first person to ask how to make it work on a DOHC, the guy knows everything about 750's. Otherwise just order the seat and make it work. Once you have it in hand you'll be able to see how to make it work.

dcmsideshow
12-22-2011, 9:08 AM
Just sent him an e-mail. I'll see what he says before I go any further.

Thanks for all the help, folks.

HWC
12-22-2011, 9:37 AM
i used this one for a SOHC..

http://cb750cafe.com/parts.php?id=109

he has avail several different ones that will work for u

dcmsideshow
12-22-2011, 10:22 AM
Hey all, got the word from Carpy and he says the seat will work. Sent some cool pictures of the seat on a 79 and an 82 DOHC. He didn't say what kind of mods it would need, but at least I know if I get it I can make it work.

Thanks again. This was really helpful!