Author Topic: DThree's 1975 cb750f cafe' build (Read 16128 times)

d3buttz · « **on:** December 02, 2010, 07:12:37 PM »

Ive come to the conclusion that ive squeezed as much power out of my cb550 as i can without throwing crazy amounts of money at it,
so ive decided to make the leap to a cb750 for the extra 200cc and also the aftermarket/OEM part availibility is much more plentiful. So lets all say goodby to the 550......

and say hello to the F! before i stripped it down i made sure it ran well, as it was parked since 1986, and it went into all gears. purrs like a kitten and doesnt smoke. sweet.

So far i have mounted the tank, transfered the seat and its mounts, clipons, started the dual disc conversion(i need to order new piston seals)

I machined out new headlight brackets and mounted them to modified tripletree clamps,

I also made a single tach mount out of a cb350 twin coil mount, i still have to clean it up and polish it, but i mounted it to make sure it worked out.

I took the day off tomorrow to take advantage of 60 degree weather and i plan to finish welding a rear loop for the frame.

Here we GO!

Rocker · « **Reply #1 on:** December 02, 2010, 07:23:17 PM »

What part did you use for the dual disc conversion and where did you get them from?

d3buttz · « **Reply #2 on:** December 02, 2010, 07:30:51 PM »

all you need is a brake line splitter from a goldwing or gl ,modify the speedo drive, another rotor, brakeline and caliper, and a bigger master cylinder/lever and longer bolts for the new rotor. the only thing you really need to be careful doing is filing down the new caliper mount onn the fork leg for proper alignment.

immortal · « **Reply #3 on:** December 02, 2010, 09:47:34 PM »

As far as the conversion to dual front rotors a lot of people are saying you need a larger master cylinder.
Im doing the same conversion myself and was in the market for the larger GL master cylinder but got talking to Carpy and Hondaman about it and both were very positive that a larger master is not needed. There will be ever so slightly more travel in the brake lever to push the fluid but the improved reaction from the dual brakes over compensates for it so you really do not need a larger master.

After speaking with those guys im going to take their advise and polish out and rebuild my standard CB750 Master and proceed that way.

Rocker · « **Reply #4 on:** December 03, 2010, 06:01:57 AM »

Quote from: d3buttz on December 02, 2010, 07:30:51 PM

modify the speedo drive

Is this because of the disc added on right interfers with the path of the speedo cable to the hub? How to you modify it?

d3buttz · « **Reply #5 on:** December 03, 2010, 04:39:14 PM »

I finished the rear frame brace today, i was going to do a loop but decided this is easier and will also aid in mounting my seat.
All i have is a 110v wire feed welder, welds are ugly, but eh, its what i got.

Hey rocker, path is unharmed-the speedo drive sits over the hub where the new rotor sits. so you must cut the bell of the speedo off untill it sits flush, and leave a 1/8 inch of material opposite eachother to bend down so they sit into the recesses of the hub(so the drive stays put while the wheel turns the speedo gear housing) Ill take some pics if youd like.

cafe550 · « **Reply #6 on:** December 03, 2010, 04:56:13 PM »

looks great!

Rocker · « **Reply #7 on:** December 05, 2010, 07:54:22 PM »

Quote from: d3buttz on December 03, 2010, 04:39:14 PM

Hey rocker, path is unharmed-the speedo drive sits over the hub where the new rotor sits. so you must cut the bell of the speedo off untill it sits flush, and leave a 1/8 inch of material opposite eachother to bend down so they sit into the recesses of the hub(so the drive stays put while the wheel turns the speedo gear housing) Ill take some pics if youd like.

A pic would be great. I was checking out my 550 front disc mounts earlier. Seems you can take a front brake assembly from another 550 and mount it on the right side of the wheel. Has identical mounting points.

Imjustanumber11 · « **Reply #8 on:** December 06, 2010, 08:02:21 PM »

Lookin good, glad i stopped to check this out, turns out you live about a 1-2miles from me, im at 42nd and Kalamath. We should get together and ride sometime.

GaJet · « **Reply #9 on:** December 07, 2010, 08:27:06 AM »

What tank and seat combo do you have? I like it.

d3buttz · « **Reply #10 on:** December 07, 2010, 04:22:56 PM »

Tank is as original Dunstall, seat is a made from an Elsinoire dirtbike tank, welcome to the forum Gajet!

Imajusta#, sure thing man! I had to tear my 550 down for this build, so no bikes are runninfg right now, but if your ever free on the weekend, drop by- were always wrenching!

d3buttz · « **Reply #11 on:** January 25, 2011, 10:41:48 AM »

I received my rear-sets from Fast from the past. great quality. I mounted them over the weekend and i have been waiting on all the many parts that i have ordered. so far the bt45's i ordered came in along with the chain. I was worried about ordering a slightly wider tire for the rear, but i think the 120/90-18 will be perfect, its not too wide to throw the handling off and from behind it doesnt look like im on a pogo stick

. I really want to mount them, but i just had 4 wisdom teeth pulled yesterday morning and im high as a kite on oxycodone on the couch. oh well...., when i feel better ill get in the garage and mount em'.

project cb750f is getting there!

seanbarney41 · « **Reply #12 on:** January 25, 2011, 04:29:39 PM »

I appreciate the crude functionality of your mods. Looks to be a cool bike.

johndregg · « **Reply #13 on:** January 26, 2011, 04:36:22 AM »

Loving this! plenty of inspiration here for me to finish my project.

Imjustanumber11 · « **Reply #14 on:** January 28, 2011, 09:10:05 AM »

Quote from: d3buttz on December 07, 2010, 04:22:56 PM

Tank is as original Dunstall, seat is a made from an Elsinoire dirtbike tank, welcome to the forum Gajet!

Imajusta#, sure thing man! I had to tear my 550 down for this build, so no bikes are runninfg right now, but if your ever free on the weekend, drop by- were always wrenching!

id be glad to come by man! hows this weekend looking for you?

FrankenFrankenstuff · « **Reply #15 on:** January 28, 2011, 09:24:50 AM »

Just throwing this out there....(I noticed a crack in your covers)

http://forums.sohc4.net/index.php?topic=74022.msg822417#msg822417

d3buttz · « **Reply #16 on:** January 29, 2011, 04:21:13 PM »

i mounted the tires and chain today!

thanks for the link frank, i will be purchasing side covers sometime soon,
imajusta# hell yeah-ill be in the garage tomorrow if you'd like to drop by- just message me here for directins

d3buttz · « **Reply #17 on:** March 07, 2011, 05:47:14 PM »

i received all my parts thru bike bandit and finally installed all of them- woo hoo!

rebuilt the carbs, new piston seals,plugs and caps, cables(push, pull, clutch, speedo) and i am especially happy with the points plate i won from ebay for cheap. its a new unused plate from the 70's and is japanese quality, not the chinese junk points going around. the rollers on the points are the good material and brass stops. it will go nicely with my hondaman ignition.
so far i took the bike around the block for a test ride, its a helluva lot quicker than my 550!!!!

im waiting for chris and motogp to finish the new 750 pipes, so i can rid the bike of the ugly stock pipe-stay tuned!

new750f · « **Reply #18 on:** March 11, 2011, 05:52:46 PM »

hey can you tell me how you mount the tank on the cb750 frame? I'm thinking about buying a like your. thanks

seanbarney41 · « **Reply #19 on:** March 11, 2011, 06:42:03 PM »

D3...would you be so kind as to tell me where you got the decals on your tank?

d3buttz · « **Reply #20 on:** March 12, 2011, 05:35:28 PM »

Hey sean, i actually picked up the decals at a antique store that purchased a whole bunch of stuff from an estate of a guy who sold stuff at motorcycle events. i picked up the only ones they had. they were probably printed 40 years ago. i dont think anybody currently prints or sells this style now.

new750f- i have a dunstall tank, and it mounts thru posts on the bottom, i dont know if the tank you are looking at mounts with posts also- but here you go!
i kept it simple and used aluminum stock, threaded it and used handlebar clamps to bolt to the frame. very solid.

The center tach wouldnt work due to the cable routing issiue with the headlight, oh well. i went back to the stock guages but lowered them 3 inches from stock height. i made spacers from 1" aluminum round stock i had laying around. very solid!

heres a video

I also started trying to pretty up the bike, so i polished the cases. boom.

im almost there!

seanbarney41 · « **Reply #21 on:** March 12, 2011, 11:41:23 PM »

Quote from: d3buttz on March 12, 2011, 05:35:28 PM

Hey sean, i actually picked up the decals at a antique store that purchased a whole bunch of stuff from an estate of a guy who sold stuff at motorcycle events. i picked up the only ones they had. they were probably printed 40 years ago. i dont think anybody currently prints or sells this now.

killer bike man, props on the unobtainium decals...

FrankenFrankenstuff · « **Reply #22 on:** March 14, 2011, 07:04:17 AM »

I love this bike.

d3buttz · « **Reply #23 on:** April 06, 2011, 04:21:53 PM »

update-
i mounted the lockhart oil cooler that was on my 550 and mounted the pipe i picked up on craigslist. 80 bucks icluding the collars and bolts!
it sounds great and there is no rust, the chrome looks great too.
pulling out the old studs was pure hell, i was using a torch to heat them to loosen them up, i tried a impact driver, yelling at it

then my buddy said "why dont you just use a pipe wrench"? ha! they came out really easy although it ruined the threads on the studs. oh well, the later exhaust collar mounting design is better in my opinion anyways.

what kind of pipe is it anyways guys???

d3buttz · « **Reply #24 on:** April 07, 2011, 05:09:05 PM »

i dislike the look of the cb750f side covers and how much the k side covers stick out, but i like how the oil tank looks on the right, so i picked up another 77/78 oil tank and cut out the backside and made it into one for the left. a few cuts here and there, welded on some tabs and bam! Its not that pretty but at least its not plastic

.

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Author Topic: DThree's 1975 cb750f cafe' build (Read 16128 times)