Topic: Slow but steady '78 cb750 rebuild

[diminished]

$hit. so the place i took my stems finally got back to me. they are going to pass. not something they want to mess with, not that i blame them, this is a bit out of there regular wheel house, i just happened to know a dude who worked there and gets me good deals on media blasting. my buddy there took it to a place behind his shop that does similar work and they want $270 to turn that stem and throw metric threads on it. seems a bit steep to me. anyone here know of a good machine shop in the seattle area that i could get to turn an aluminum stem down to specific specs and throw some metric thread on for a reasonable price? i pick up the lower cases tomorrow so expect pics of them in there bead blasted glory.

[brettster26]

Although FunJimmy did his modern forks on a 550 instead of a 750 he may have some valuable information for you and he is a guy that has tons of information and is always willing to help you out with questions you may have about his build.  Search his posting "CB550 Cafe Interceptor"  He goes in pretty good depth about how he went about fitting his front forks.  http://forums.sohc4.net/index.php?topic=27159.0


Hope he can help you out!  Should be a good build!

[brandEn]

Check out The Wheelmaster in Auburn. I just picked up my wheels from him today in fact. He works for cash out of his own shop next to his house. He has an amazing machine shop and specializes in stuff like that.
http://thewheelmaster.com/

[Blitzburgh207]

Subscribed! Inspiring build man.  Very similar to what I've been dreaming of but that will have to wait until I'm out of school! Keep up the great work! 

[diminished]

when i said slow but steady, i meant it, hehe. so bout time for an update? ended up taking the GSXR stem to autosport in seattle. the dudes down there took my original stem, the GSXR stem and for a scant $90 they turned the GSXR stem on the lathe so it would accept the hardware/bearings from the CB. amazing work, fast turnaround, and awesome dudes to deal with. Highly recommend them for any custom metal work.

now ive been trying to figure out a set of spoked wheels to use that would be unique, fit on a 25mm axle, and give me lots of options for rotors/tires. what i ended up deciding on is the alpina tubeless spoked wheels for the ducati sport classic. picked them up from JC/PakBikes, bit pricey but dear sweet jesus they are worth every penny. took about a month for them to arrive but they are beautiful. picked up a set of used brembo aftermarket floating rotors for the front, and a stock rotor/caliper/mount for the back. ill have to fabricate a set of spacers for the calipers on the front as the GSXR uses 310mm rotors and the sport classic uses 320mm, and i have to put the front wheel on with the rotors loose to be able to squeeze the caliper onto them, but other than that, freaking awesome. i'll be taking the boxed carpy swing arm down to autosport to have them enlarge the axle hole to 25mm so i can fit use a stock ducati rear axle.

no one makes the gordon kit anymore. i went through all the dudes that used to make it here on the forum and no one still does, so i ended up going with the cycle x frame splice kit. got the frame cut and tacked the splices into place and my brother in law tig welded them for me. not as elegant as the gordon kit but it will get the job done.


LOTS left to do/get. seems like every time i get one thing done it leads to 5 more. still an uphill battle but im starting to see the crest of the hill at least, haha.
pictures? ive got a couple on my phone so not the best quality, but you get the idea.

[brandEn]

Holy crap those wheel are sick. You gonna have that thing rideable by summer?

[lucky]

@lucky - scorpio stuff? you talking about his star sign or a manufacturer?

Talking about Astrology. Time you were born.
All of our DNA is affected by electromagnetic pulses that are occuring
at different months and different solar cycles. Long discussion. Has nothing to do with religion.
Ever wonder about all the black and red color schemes?
He likes to show you all his stuff. Typical.
He seems like a good guy though.
His exhaust system is a good product.

BTW...That rough edge that you see when looking in through the clutch case opening is normal. Just a rough casting edge.
All those metal filings on the floor, where did they come from?

[Nick_701]

Wow very cool i cant wait to see this. Keep up the good work.

[billybobobrain]

Subscribed

[OneWheelDrive]

Update?

[Mtmooradian]

Nice work, I ended up machining a lower to accept a cb stem. If you need any machine work you could send it my way.

[lucky]

So awhile back I picked up a 1978 CB750 from some kid up in the mountains for $1200 bucks, he had gotten a DUI and had to sell his toys to pay for courts/lawyers/etc and this was the first of them to go. Ive been a fan of the cafe stuff for years, and now that I'm in a house with a garage and have a good steady job I figured its time to start a project. Its amazing how fast tear down goes, and I know that I didn't get as many pictures as I should have, so expect lots of "what the hell am I looking at now" type posts, haha. Since this is my first tear down/rebuild of anything larger than a lawn mower, so I'm taking my time and trying to document everything.

to kick things off i spent a butt ton of money at cycle x. they bored out my jugs to 849cc, and are doing a port job as we speak. they are shaving my crank down to their "pork chop" which lightens it ~7 pounds. new APE studs, new valve springs, titanium retainers, C2 racing cam, heavy duty cam chain, over-sized valves, they're pressing in new guides, cycle X rods, whole new gasket set, new cam chain, new primary chains, they coated my new pistons with a heat barrier/skirting, rocker arms and shafts coated with the same good stuff, spin on oil adapter w/adapters for an oil cooler, electric ignition, and high voltage coils.

next shipment is going to be their 4-2-1 race exhaust, a set of mikuni rs 34mm, and a frame splice kit (since no one here will make the gordon kit anymore. i tried contacting voxonda and he got back to me once, 3 months ago, no word since).

when i get the head back ill be going down to Performance Coatings to have my head, jugs, and valve cover sprayed with a thermal dispersant.

lower cases and frame will get powder once i decide on a color scheme, and i'm going to have to twist brandEn's to find out who did his gorgeous paint and seat.

in the interest of making this a looker, i picked up a bunch of the joker CNC stuff, the alternator cover, the clutch cover, the starter cover, the points cover and the gas cap.

just took delivery of a benjie's whale tank w/knee cutouts. Going to take the stock seat pan and cut it up till it looks good, add a bump out and hide electrics in there.

i picked up a gsxr 600 front end, and this weekend im going to grind the welds off the stock stem, press it out, and follow industrial cafe's lead and swap out the front end on this beast for something a bit more modern. only difference is ill be either using a set of ducati sport classic wheels, or the tubeless alpina's. wanted to have something with a bit more rigidity and larger contact patch then the harley narrow glide stuff, but want to keep the spoke look.

ive got one of carpy's dresda style boxed swingarms coming, and will be modifying it a bit to accommodate a rear caliper.

i would like to run an m-unit from spiegler, if anyone has any experience with them good or bad chime in. i'd love to hear it.

i think that about covers my plans, now lets look at some pictures:
the kid i bought it from had "cafe'd" it, but to him that mean flattening out the seat, pulling out the air box to put pods on, and slapping a set of clubmans on her. its a shame, but this is the earliest photo i have. got so excited to tear her down i forgot to document her humble beginnings.


im definitely not the first one to tear into this engine, and i found all sorts of fun stuff inside, dead moths, a bunch of metal shavings, the retainer spring for the kickstart pawl broken in two, weird stuff. luckily the top end looked pretty good to start with:


original studs, couple of them were stripped on top but they all came out. pistons look like we've been running rich for awhile:


pre-porting:



time for the fun, the lower half. she was leaking oil in a couple of spots that whoever rebuilt it originally screwed up the liquid gasket, but she was all there. pretty clean for the most part, considering the metal shavings/other possible grenade sh|t that was in that lower case.


on transmission, second gear from the left, there is a thin indent in the cent of the gear. is that normal/stock? time to replace it? also ive heard rumors that there is someone out there making a billet clutch basket, and mine has seen better days. anyone know who makes that, and what kind of cost?


this shifter arm has a bit of wear toward the end of its arm. should i replace that bad boy or is that cool? (ignore the metal shavings there, had two stuck screws i had to drill the heads off of and twist out.)


and this was something i just wasnt sure about. to tell the truth i didnt see it until i slapped the empty cases back together and on the bike to get an idea of which mounting brackets i wanted to keep and what i wanted to shave off. in the hole where the transmission came out of i spied a bit of a rough edge to the metal. it looks like there once was something there and it either broke out or was removed. any thoughts?


side note: ive got parts that ill be selling if anyone is interested. make me an offer and if its reasonable there yours. much rather dudes here get these parts then ebay them. will expand this list as im ready to sell more.
front master cylinder, front caliper, mounting bracket. prefer to sell as a package
front forks
rear wheel with sprocket and drum brake insert
front wheel with rotor
original alternator, starter, and clutch covers. a bit dented but ill give them to you for the cost of shipping. seriously.
front headlight ears w/original turn signals
rear turn signals

Don't worry about that rough edge on the transmission case. Everyone comments on that.  If you want you could smooth it down, but don't nick the case!!!