Topic: 78 CB750F "Modular-ish" cafe build?

[CafeDawg]

Don't know if you've seen this, might provide inspiration.
1976 Honda CB550 Cafe Racer Bobber convertible

Like the idea.

Love my F3 with Corbin seat
Respect
CD

[madScientist]

I have not seen that! Thanks! Very cool and I like that they're able to do it in < 6 minutes.

With the corbin seat, can you ride two-up?



did anyone else notice the one dude has a tramp stamp?

[lucky]

Subscribed.  I have a 77F that I want to do in the same way.  I love the cafe look, but the girlfriend will demand a ride from time to time!

I'll be curious to see how this turns out!

Yes and with this bike the girlfriend will not have her bum way up in the air
like the new silly bikes.

[madScientist]

Thats exactly her complaint about the VS1400...aside from the fact that the rear seat is a glorified brick. She does enjoy riding with me however her last experience on the F wasn't terribly enjoyable. At the time I took her on it the heads leaked, the exhausts didn't seal well, and it leaked gas...so we smelled GREAT when we were done.

[CafeDawg]

Technically yes you can ride two up but it's not really designed for long rides.  I don't ride two up and have removed rear pegs but it is possible. 
http://i1198.photobucket.com/albums/aa457/CafeDawg/IMG-20121009-00359.jpg[/img]]

Respect
CD

[750resurrection]

If the GF is petite they like the high up deal.

When you're driving behind the silly bike, the hinie is smiling at you.

Petite can also see forward better, with less lean to either side.

Whisper in your ear.

 I know the old timers preferred having their lower belt area grabbed at by their riding honey while she hung on. Can't say the old timers are dumb. 

[lucky]

It's been a pretty productive day. I got the forks taken apart. Got the frame kit finish welded. Started taking the brake calipers apart but the pistons are really stuck in the housings and i'm trying to not grab hold of them with a set of channel locks.

I also spent about an hour with the acetelyn torch, a hammer, and chisel trying to get the lower bearing race off the tree post. The bearings literally disintigrated when I slid the tree off the neck...little marbles EVERYWHERE! The bottom race was fused to the lower part of the tree but a little bit of heat and brute force knocked it loose.

The icing on the cake though was getting the seat perch figured out. I originally planned to just drill holes and tap them. This proved futile when I realized the frame isnt' think enough to really accomodate threading...even with fine threaded bolts. So I flipped to plan B. That consisted of drilling bigger holes and welding nuts into the frame. SUCCESS!! I still need to grind it smooth but the nuts are in there and they work great! I also need to get the bolts to set flush against the frame. i might weld inserts underneath the perch between it and the frame and then drill the holes extra wide? Or perhaps grind the tops of the screws down since the phillips recesses are pretty deep.

Took a picture of my helper today...it never fails she'll look away as soon as you hit the camera button...

The bearing did not . Back then there was no bearing cage. It was like a bicycle. Just loose ball bearings. the reason they fell out is dried up grease.

[lucky]

It's been a pretty productive day. I got the forks taken apart. Got the frame kit finish welded. Started taking the brake calipers apart but the pistons are really stuck in the housings and i'm trying to not grab hold of them with a set of channel locks.

I also spent about an hour with the acetelyn torch, a hammer, and chisel trying to get the lower bearing race off the tree post. The bearings literally disintigrated when I slid the tree off the neck...little marbles EVERYWHERE! The bottom race was fused to the lower part of the tree but a little bit of heat and brute force knocked it loose.

The icing on the cake though was getting the seat perch figured out. I originally planned to just drill holes and tap them. This proved futile when I realized the frame isnt' think enough to really accomodate threading...even with fine threaded bolts. So I flipped to plan B. That consisted of drilling bigger holes and welding nuts into the frame. SUCCESS!! I still need to grind it smooth but the nuts are in there and they work great! I also need to get the bolts to set flush against the frame. i might weld inserts underneath the perch between it and the frame and then drill the holes extra wide? Or perhaps grind the tops of the screws down since the phillips recesses are pretty deep.

Took a picture of my helper today...it never fails she'll look away as soon as you hit the camera button...

The bearing did not disintegrate. Back then there was no bearing cage. It was like a bicycle. Just loose ball bearings. the reason they fell out is dried up grease.
to get the caliper pistons out just apply air pressure, or use a grease gun.
Then it will not be damaged.

[lucky]

The top end of the engine is apart. I'm probably going to err on the side of caution but...is this cam chain guide and roller usable?

NO, not unless you like little bits of 35 year old hard rubber all through your oil galleys.
Ask others on this forum what can happen.
See:
http://forums.sohc4.net/index.php?topic=95554.0

[lucky]

If the GF is petite they like the high up deal.

When you're driving behind the silly bike, the hinie is smiling at you.

Petite can also see forward better, with less lean to either side.

Whisper in your ear.

 I know the old timers preferred having their lower belt area grabbed at by their riding honey while she hung on. Can't say the old timers are dumb. 

If I was the GF I would not ride more than 10 feet with that seat. Got to be kidding.
Below is a side view of a real GF seat. She will be very happy and like you a lot.

[750resurrection]

" Thats exactly her complaint about the VS1400 "

 Okay so the other day I went and looked at a vs1400 pic didn't know what it was, also many crotch rockets have an exaggerated deal going on with no backrest, no back padding, and perhaps no rear grab bar. The hinie smiles rearward.

 The Corbin seat needs another wedge pad strap on before anyone could possibly feel safe from sliding off, so yeah Lucky you and everyone else wouldn't last ten seconds...

 The King and Queen is what I've almost always wound up with. The honey always gets a backrest, whoever doesn't like it that's their problem no matter the bike. I get a backrest if I want one. That's how I roll but I have no problem if someone else likes a high seat or some slickup rear with the honey's hinie in the air and her chest on the driver while the nut and gut hug the bloated tank. 

[madScientist]

So that's a definate "No" on re-using the cam roller and guide. Thank you for clearing it up for me. I figured I should bank on replacing anything rubber inside the engine anyhow.

I'm rethinking the corbin now. I have a perfect condition factory seat in the shop that I might give a whirl when the time comes but I'm still about 6 months off from making that decision.

I worked at getting the head studs out today. That's an exercise in annoyance and frustration...With a little encouragement from the acetylene torch I have all but 4 out. However I did break one. It was really brittle to start with so I kind of figured it was going to let go no me. I have enough of it sticking out that I (or machine shop) can weld a bolt to it. I might give it a crack tomorrow or Sunday.

The only thing she likes about the 1400 is the taller backrest I made so she's not afraid of falling off. The factory one was gouging in her back so I made one a foot taller out of rebar.

I was wondering how you guys feel about the stock connecting rods being used in an 836. In cruising the forums I've seen some people say they are needed and others say no. There doesn't seem to be a consensus. I'm not afraid of picking up a set of Carillos if they are really necessary however on this bike I'd like to keep my costs from running away. The bike isn't going to get run super hard. However it will occasionally get pushed. Let me know your thoughts.

Thanks guys!

[750resurrection]

 Cafedawg adding that video goes to show your idea is possible and desirable.

 " The only thing she likes about the 1400 is the taller backrest I made so she's not afraid of falling off. The factory one was gouging in her back so I made one a foot taller out of rebar. "  Awesome.

[SOHC4 Cafe Racer Fan]

Carrillos are overkill for your needs. You might still want to upgrade while you have it apart. Take a look at Cycle X Super Rods. A good value.

[madScientist]

Well it's been about a month since posting and a lot of progress has been made. I finished up all the welds on the frame kit that I wanted to do. I was having a hard time getting it "perfect" but eventually got it damn near. I had that and a bunch of little bits sandblasted. Had the rotors blasted too but I'm starting to question whether that was a good idea...

After that it was off to the powder coater. I found a really great coater near my work. Les Schneider with Powder Coat Specialist. This is the same guy who does (or used to at least) the frames for the monster truck "Gravedigger". I picked all that up yesterday. I have my frame in the living room right now because I probably wont get a chance to work on it for a little while and it's a work of art. Strangely enough the missus agrees and is letting me leave it there! She gives me a lot of flack for my projects but deep down I know she likes watching them unfold

While that stuff was being done I split the engine apart. The transmission looks perfect. Bearings spec'd out. I do think I'm going to replace the main and rod bearings for added piece of mind. I think I've decided to leave the rods alone and run stock. I dont anticipate this bike to make CRAZY power with the 836, stage 2 porting, and cr29's. I had the cases blasted and started painting them.

Over this month I'm going to get the cases painted satin black. The inside will be glytal'd. I'm also going to get the frame up to roller status. I'll post again when progress has been made! Thanks again for your support and encouragement guys!

[madScientist]

Sorry it's taken so long to post. I've been making progress slowly. I received my swingarm a few weeks ago...freshly rebuilt by the forum's very own Hondaman. Big thanks to him! He did more than I ever could have imagined on that thing. So far I've gotten the cases painted both inside and out. Glyptal is on the inside, VHT is on the out. I have new tapered bearings in the stem. After cleaning out some frustrating sand out of the fork legs I have them back together as well. This was also after I managed to break the left one. There was sand in the drain hole and i didn't tap it out. The bolt stuck, broke, and in my fiddling i cracked out the other side. Got a replacement and we're good to go.

I also ordered the stuff for the lower end of the engine. It all arrived last week. I have all this new stuff!
-- primary chain tensioner
-- primary chains
-- rod bearings
-- main bearings
-- cam chain
-- gaskets
-- oil seals
-- a massive amount of new bolts from McMaster Carr
-- some other odds and ends
-- cafe seat

The pedestal modifications also works great! I have been able to put the old seat back on and remove everything for the cafe seat. Still a long way to go but now I'm going to focus on the engine for a little while. I prefer working on engines.

My goal, if i can stay on schedule, is to have the lower end done this month. Next month my head will probably make it's way to either APE or cycleX for a rebuild. Probably pick up the 836 kit. February the jugs will be machined and the head will make it's way to MRieck for some magic. March = electrical and carbs. April paint and final touches. We'll see if I stay on course :-D

[madScientist]

It's WAY ahead of time to be thinking about this for real but i've been trying to figure out what I want for paint.

I was initially thinking a dark silver with black GT race stripes or black with silver stripes. This weekend I was working on my buddies shelby cobra that is ford Royal blue with white stripes and i really liked the color.

So what i kind of see now is a Lexus Spectra candy blue with a wide stripe down the middle accented by 1/8" stripes on each side of the wide strip in aluminum color. With a light flake over the top of the whole thing. Side covers i think will also be blue with "SS 836" in chevelle styled lettering. Might can the lettering idea as too tacky when it comes time. That's about 5 months down the road though.

Just putting my thoughts out there as a stream of consciousness type of thing...

[Mercutiojb]

Could you detail your mods for fast-switching the seats?  You mention that it's working well, but you haven't said what you've done (I don't think, anyway...)

Also, is that the Airtech seat?

[madScientist]

Certainly!

1) I drilled a couple of screw holes through the seat perch (for screws). I originally tried to tap the holes in the frame i made to screw the seat perch screws into but it was too thin to tap. So instead I welded nuts in the frame that are the same size and pitch as the machine screws i intend to use to hold the seat perch down.
2) Made a small bracket consisting of about 2 x 1 steel (about 1/16" inch thick) and welded it directly to the seat lock mount and formed it to the contour of the frame with a body hammer. Drilled a couple of holes in the bracket through to the frame. Cut the seat lock mount off. Welded nuts in the holes, same as the seat perch. I think earlier in the thread I have pictures of these.
3) cleaned the welds to be smooth with a 180 flap wheel on my grinder

Pictures:






Now the seat lock and perch can be added and removed when you want to change up the seats.

Yes it is an airtech seat. It is the CB75022 long chassis. I have not gotten the seat mount as i might make my own.

[madScientist]

Over the past few weeks I've been focused on motor work and little things that dont cost an arm and a leg since my funds are getting a little light for my taste.

I've gotten the rear wheel cleaned up with some steel wool and elbow grease. I'm doing the 530 chain conversion so I purchased a JT 48 tooth rear sprocket with a 17 tooth front sprocket as that seems to be the combo most used. I also painted the rear disc and polished the rivets. The dremel is getting a LOT of use these days.




I put the rear wheel on the bike but neglected to take a picture. However I had to use the old shocks since I haven't purchased new ones yet. The shocks are a little far down on my list of things to purchase but I'll likely be going with Icon's...probably in April when I'm close to being done. But hey...the bike is standing on it's own. I've also noticed that my right fork is leaking out the bolt hole in the bottom. I guess I didn't get it tight enough but it's not a major deal yet on my floor since I didnt' put oil in it with the exception of a little on the fork tube for assembly.

So the engine...I plastigauged the new connecting rod bearings and crank bearings. They are now within spec with the green crank bearings and brown rod bearings. The new primary chains and HD cam chain are installed...I also put new connecting rod bolts in because the previous ones looked stretched (one was shaped like an hour glass). The trans gears spec'd out. No damage on the dogs, bearings are well within tolerance. So here it stands:





I did run into a problem. I guess I'm over tightening the M6 bolts as when i went to assemble it I broke one of the M6x100 bolts leading me to take it back apart. Kind of sucks since i have to clean off the freshly applied three bond. Oh well...should have all new bolts tomorrow and be back to assembly. I think that's all for now...sorry for the long read.

[iron_worker]

Why the paint on the inside? Seems like a lot of work masking all the machined surfaces and prepping for little gain?

It does look good though. lol

IW

[madScientist]

The paint on the inside is Glyptal. It seals off the porous metal on the inside of the engine. This helps to increase oil flow and assist in keeping the oil clean. Plus it looks nice and I was waiting on parts so i figured why not :-D I would figure it's more useful in cast iron blocks as they are extremely porous.

I've been using glyptal in my car engines for about 8 years now. There isn't any definitive proof since there are too many variables affecting performance but a few years ago I built identical 347 stroker engines (i'm a ford guy...please dont hate me). I'm very anal about my car engines since I sell most of them to hot rodders who demand high returns. Anyways, identical part numbers, everything blueprinted and spec'd exactly the same. All tolerances the same. The ONLY difference was I elected to NOT glyptal one engine and glyptal the other.

The results showed that the glyptal'd engine yielded roughly 4hp and 2ft lb more than the non glyptal'd engine at they flywheel. This gain however would not be seen at the wheels due to a roughly 12% loss in HP through the drive train. It also had an average of 1.3psi more oil pressure. If it matters to you the glyptal'd engine exploded at 8500rpm and the non glyptald one at 7900rpm. The glytpal'd engine threw a couple rods (through the valve cover...pretty cool to watch!) and the non glytal'd engine dropped a valve (and stripped a rocker).

Like I said this isn't definitive proof that glyptal does anything but increase the aesthetic appeal and make me happy.

It does look good though right!

[Blackandsilver]

Looking good man! I originally wanted to go combo solo or two up on mine but the gf perch turned out about half the size it shoulda been. Oops. Stoked to see how she turns out. Great motor work!


Win some lose some, it's all the same to me.

[madScientist]

Thanks! I'm anxious to start getting pieces back in it to make it look more like a bike.

I'm sure my gf is going to want me to fab up a sissy bar once she see's the finished product.

[SOHC4 Cafe Racer Fan]

Purrty looking motor.