79 CB750K, RCB clone-ish build

[boingk]

Re: 79 CB750K "Off Track"/ Swing arm issue...

While I really appreciate you being honest and saying on the last page that using a longer swingarm is purely for cosmetic reasons, you may now see my point in asking why you are doing this. Bottom line? If the stock setup works well, why change it? Rock some uprated shocks and true the rear wheel, you'll be fine! With none of this side-to-side mojo either.

Anywho, liking the lowered tank setup very much and still can't get over the champ state of your wheels and engine. Keep up the good stuff.

Cheers - boingk

 

[Basement rat]

Re: 79 CB750K "Off Track"/ Swing arm issue...

Ok, Last night... After 8 hours of "work" at work I came home to WORK on the bike. I worked on the bike for a good five hours, was done and just had a shower when I wrote this. Checked this morning when I got some laundry The bike axle is too small for the axle in the SA. Im going to try to hunt down the oriognal this weekend. Hopefully its still in the frame of the donor bike.

Now why this SA? Why most of anything cafe? I see tons of very clean very ride able bikes on here turned bob, chop, cafe, and even... street fighters especially. Why? Looks.

Why?

 

[Big R]

Re: 79 CB750K "Off Track"/ Swing arm issue...

Why?

Bet the owner of this wears kevlar underwear.

But keep it up man! Everybody runs into bugs in a build, you'll get through everything and have a killer bike.

 

[thompsonmx100]

Re: 79 CB750K "Off Track"/ Swing arm issue...

Yes sir you are correct when you guessed that you did not want side to side play. Very bad for handling. When I installed my swingarm I had some slop. The gsxr had one washer under each dust cap. I just had to get two more for each side. You also want your swingarm pivot bolt to be a snug fit. If you need to fit a larger pivot bolt for that swingarm you may consider making a new spacer with the correct I.D. and O.D.
Just my opinion some things I have learned along the way.

 

[Basement rat]

Re: 79 CB750K "Off Track"/ Swing arm issue...

Thanks, The spacers I think are fine. When I pulled the axle out and compared it to the inside of the SA shaft there is much more slop than the arm actually showed because my spacers were so tight. I will turn down some brass bushings and press them in to the SA pivot to accept the cb axle. This way if ever I decide to return to stock (important aspect here) i can use the oem axle and arm no worries. I will do that after work next week. This weekend I need to worry about getting my rotor cross drilled, clean and paint my caliper and I don't know what else right now.

Going to the store for some root beer now... MMMMmmmm A&W Root Beer.

 

[thompsonmx100]

Re: 79 CB750K "Off Track"/ Swing arm issue...

Gotcha sounds good. Should take care of your problem.

 

[mysta2]

Re: 79 CB750K "Off Track"/ Swing arm issue...

I like the bike...

...but I love the (BEEF?) poster, what's it for?

I want one for my garage!

 

[Basement rat]

Re: 79 CB750K "Off Track"/ Swing arm issue...

Stop, its what brakes do.


The poster... its for moral...

http://www.allposters.com/gallery.asp?startat=/getposter.asp&APNum=2113996&CID=AB565EA3B0614ECABC19AA65923B6532&PPID=1&Search=pin%20up%20beef%20curves&f=t&FindID=0&P=1&PP=43&sortby=PD&c=c&page=1


Update, I will let this speak for its self:

Took about two and a half hours from figuring out what pattern I wanted to center punching to center drilling to drilling to deburring. All by hand, eye and drill press.

See if I cant get the inside and caliper painted gold tonight.

 

[Rocan]

Re: 79 CB750K "Off Track"/ STOP!

you can drill that rotor out a LOT more then that...

 

[jay_kent]

Re: 79 CB750K "Off Track"/ Swing arm issue...

Update, I will let this speak for its self:

Took about two and a half hours from figuring out what pattern I wanted to center punching to center drilling to drilling to deburring. All by hand, eye and drill press.

See if I cant get the inside and caliper painted gold tonight.

Looks good, those are a pita to do. very clean

Jay

 

[thompsonmx100]

Re: 79 CB750K "Off Track"/ STOP!

Looks good. Keep it up.

 

[Basement rat]

Re: 79 CB750K "Off Track"/ STOP!

Toight like a toiger:

After about 6 hours on a shitty lathe with no feed, a compound rest that wants to move with any cut more than .1" and a hunk of "scrap" brass, I came out with this:

tapped in place with some cherry flavored loc-tite (the red one)

seems I need to grind a little more away from the back of the transmission...

Also, My ebay brake light came in. This is about 35' away lights off, left signal on.

ebay link if interested

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=320460748566&ssPageName=STRK:MEWAX:IT


My tank... Ive been talking to Sean at Roccity and I am going to try to modify a 750F tank to fit under a fiberglass positive mold of the blue dunstall. If it wont work I will seriously think about buying an "alloy" tank from him in that style. One, I'm cheep ass bastard, two I just GOTTA try it myself first.

Sean, no offense intended, your a first rate guy.

 

[Basement rat]

Re: 79 CB750K "Off Track"/ TOIGHT!

I'm going this weekend to pick up a 750F tank. I got the idea that more gas is better. What if while I'm at it, I extend the steel tank under the seat of the bike for increased capacity? This is done in many snowmobiles where like bikes, space is an issue.

whats wrong with this idea?

 

[Big R]

Re: 79 CB750K "Off Track"/ TOIGHT!

Nada except I would guess it might be hard getting it to fit correctly. Not impossible but tough. And the increase in tank size is only a benefit when you can get the gas to the petcock. So you might have to move that too. Again, not impossible.

Plus gas gets freakin heavy! If you are out ripping it up on 1/8th of a tank and fill her up, might throw you a little off balance when you get back out on the road.

Way to think outside the box (or tank in this case)!

 

[boingk]

Re: 79 CB750K "Off Track"/ TOIGHT!

I like those bushes, and the tank idea isn't bad. I'm rocking the standard 22 litre (6 gallon) tank on my GS and dont mind how it looks at all. Extending it under your seat might get to the point where you are sacrificing comfort for tank volume, rear clearance for volume, or both! I wouldn't compromise any of those things when you'll be holding a lot in the 750F tank anyway. At the end of the day if you've got more than 15 litres you should be peachy.

Cheers - boingk

 

[Basement rat]

Re: 79 CB750K "Off Track"/ TOIGHT!

Extending it under your seat might get to the point where you are sacrificing comfort for tank volume,

WTF are we doing building cafe racers?

Im still going to mess with the idea of utilising that space for some kind of payload. Be it fuel, most likley electronics or even my tool kit. I will be sticking my battery in the bump stop.

Wonder why that idea was never really explored? Sitting on some of the gas tank... Lots of space, you woulden have to ride like a dog shitting razer blades all hunched over (a much as it helps with aerodynamicity). Comfort? have you seen the classic race bikes? a little foam pad on a fiberglass seat.

 

[VonYinzer]

Re: 79 CB750K "Off Track"/ TOIGHT!

Building a cafe racer STYLED bike for the streets doesnt mean building an uncomfortable bike... Nobody here is building a real racebike (well almost nobody). Lets be honest with ourselves. If everyone were buildin real vintage racers there would be a whole lot more talk about engine work, and frame modification, and so forth... Sure these arent DynaGlides or GoldWings, but they can and should be at least comfortable enough to get a good ride in. Im not saying anyones wrong in their builds. Just having a bike that looks good and is comfortable is what every manufacturer in the history of motorcycling has been trying to design since the get go. Anything else is silly and even dangerous for the street. Im not crushing on anyone, hell im painting a bike with a stock motor (for now) to look like a race bike, but its not a race bike. Its a street bike. And I want some comfort.

And also, I think the build is coming along nicely, and a stock F tank should be plenty of gas for a daily rider. Storing your elec. and/or tools inder the seat sounds like a great idea. Having your tools along for the ride is a necessity with these old girls on the road. Im doing something similar with my 350.

 

[Rocan]

Re: 79 CB750K "Off Track"/ TOIGHT!

Building a cafe racer STYLED bike for the streets doesnt mean building an uncomfortable bike... Nobody here is building a real racebike (well almost nobody). Lets be honest with ourselves. If everyone were buildin real vintage racers there would be a whole lot more talk about engine work, and frame modification, and so forth... Sure these arent DynaGlides or GoldWings, but they can and should be at least comfortable enough to get a good ride in. Im not saying anyones wrong in their builds. Just having a bike that looks good and is comfortable is what every manufacturer in the history of motorcycling has been trying to design since the get go. Anything else is silly and even dangerous for the street. Im not crushing on anyone, hell im painting a bike with a stock motor (for now) to look like a race bike, but its not a race bike. Its a street bike. And I want some comfort.

And also, I think the build is coming along nicely, and a stock F tank should be plenty of gas for a daily rider. Storing your elec. and/or tools inder the seat sounds like a great idea. Having your tools along for the ride is a necessity with these old girls on the road. Im doing something similar with my 350.

who says race bikes cant be comfortable?

sure, they arent going to ride like cruisers, but they can be comfortable enough for street use.

And a well thought out and built engine only adds to comfort.... less vibration.

 

[Swagger]

Re: 79 CB750K "Off Track"/ TOIGHT!

Umm...well, I guess that depends on your definition of comfort and the quality of the roads you ride.
When I was using the Triumph as a track-day only toy I had the suspension dialed in for that purpose and I'll tell you that it was harsh and unforgiving on the street. Until you hit about 50mph your bits were driven into your lower intestine with every chop and expansion joint and slight ding in the road surface. As well, an engine tuned for the track is a different animal that a street lump. If it's really tuned for racing your losing torque to allow for more hp on top...again, not so good on the street.

Not saying that one has to stick with stock anything, just that a real race bike....bitch on the street.
Ask PJ...I'm sure he's got stories...I've heard about some of his bikes....

 

[Basement rat]

Re: 79 CB750K "Off Track"/ TOIGHT!

Press play then look at pictures...

http://www.youtube.com/watch?v=iuyT9STDO78

Yes, I see that rust too, but who cares? A simple patch and go! I need not even worry about grinding the welds down because nobody will ever see!

The theory is if I leave the two like that, I should have a perfect compilation of the two.

Seriously, like said above, a nice simple positive copy of the Dunstall "mounted" on the steel one. Is expanding foam too ghetto for this?

As for my filler cap between the two... Im thinking about using an OEM cap on the SS tank inside the shell and having a little hinged door that opens up to it like a car. Nice and clean.

I think this just might work... Might have to buy a shot paean too.

I also bought a pile of crap on ebay today. Gasket set, bid on carb rebuild kit (using dads carbs now that will go on dads bike when I pick it up), bought some fork dust seals and thats enough for a pay cheque!

Im going to "mount" ;D my "swing" arm tomorrow and see how everything works together. I'm also going to try my stock chain and see how everything fits. It only has 12,000 ish km on it so it should be good for a few more years?