Topic: 1978 CB550K4 Project

[SOHC4 Cafe Racer Fan]

What do you do when the 550 bug bites you, and you don't want to modify a nice bike? 

I bought this 1978 CB550K4 on the cheap.  It's a runner, but the carbs need work, the front is wobbly and the engine has leaks at the shift spline, head gasket and valve cover gasket.  That said, it's all there and the makings of a solid build project donor.











My initial thought is to go with a modern/USD GSXR front with Cognitomoto custom offset tree, modern box-style swingarm, 18" wheels, and something peppier for the motor.

[Mcwilliams570]

Looks like a nice start cb750 those parts are so nice from Cognito Moto.

Matt

[tweakin]

I'll follow along.  That donor bike looks pretty good and could be a restore IMO.  But opinions are like arseholes and it's your bike, do what you will and enjoy the crap out of it...

Seems like we might have a similar addictive personality. 

[SOHC4 Cafe Racer Fan]

I'll follow along.  That donor bike looks pretty good and could be a restore IMO.  But opinions are like arseholes and it's your bike, do what you will and enjoy the crap out of it...

Seems like we might have a similar addictive personality. 

Thanks, Tige.  She looks good from far but far from good.  She'd be a restoration candidate in the Tige book, but I really wanted a runner to make into a light weight carver.  The idea is to eventually hand this bike over to my nephew.  I want to give him something that will stop and handle much better than stock, and be naturally nimble.

[UNFORTUNATELY: the nephew has since failed to show any interest]

I'm going to use a 1976 750 Super Sport tank modified to fit the 550 frame, with both knee dents and clip-on dents inspired by Raccia's 550 build.



Speaking of clip-ons, since the front end didn't come with the stockers, I picked up a set of Woodcraft clip-ons:

[tweakin]

Nice, you nephew will be for ever great full.  I run woodcraft clip ons on the the 915 and love the fit and finish.

[gheorghe]

Nice ride, I'm about to place a similar order to Cognito, I too have my GSXR fork, Can't wait to see the direction you'll be going.

[SOHC4 Cafe Racer Fan]

I've been trying to rummage through my spare parts collection to scavange for this bike.  That said, I will need to start budgeting for parts.  I'm trying not to get ahead of myself as I want to have my K2 750 well in hand before I go at this 550 build in earnest.

[SOHC4 Cafe Racer Fan]

Nice, you nephew will be for ever great full.  I run woodcraft clip ons on the the 915 and love the fit and finish.

He's a great kid.  17 years old and no attitude.  He works his ass off in school, plays drums in a garage band, and runs cross-country.  I'll have to find something for him to learn to ride (that can be dropped without any heart attacks) before he graduates to this.  Maybe a cheap enduro (dual sport).  At least with the modern brakes and forks, the bike will have drastically improved braking and handling, and I will feel better not giving him a rickety bike with the stock brakes and forks.  This bike rides extremely wobbly, as the steering bearings are pretty well shot, and the brake feels wooden.  I've already purchased All Balls bearings and steel braided lines to go with the new front end.

[SOHC4 Cafe Racer Fan]

I'm undecided on the seat. 
Option 1:  I have a spare Carpy Vincent style seat that I could use and call it a day:



Option 2:  I like the look of the Dime City seat used by Jojo on his 750 build:





Option 3:  A bratstyle seat with a removable speed-hump cowl (that would allow for two-up riding) similar to this with a cowl that goes on top of the rear portion:





Has anyone done something like Option 3?  Opinions?

[Trad]

Hey Don, in for this for sure!

[SOHC4 Cafe Racer Fan]

Hey Don, in for this for sure!

Thanks for finding me a 650 cam!!

[jojo]

I'm undecided on the seat. 
Option 1:  I have a spare Carpy Vincent style seat that I could use and call it a day:



Option 2:  I like the look of the Dime City seat used by Jojo on his 750 build:





Option 3:  A bratstyle seat with a removable speed-hump cowl (that would allow for two-up riding) similar to this with a cowl that goes on top of the rear portion:





Has anyone done something like Option 3?  Opinions?

Id go with option number 3  if you have a mrs cafe racer fan that likes to tab along from time to time. Otherwise id go with option number 2

[SOHC4 Cafe Racer Fan]

I was thinking of keeping the 2-up riding option open for my nephew.  To that end, I will have to be creative with respect about passenger pegs, since I am planning on using rearsets.  He's a taller kid.

[thirsty 1]

Seems you need a hobby....

[gheorghe]

I'd vote for option number 2. If the DCC price is a bit hard to swallow, Motolana has a similar seat thats a bit cheaper but looks every bit as nice

[SOHC4 Cafe Racer Fan]

Don - might also give some thought to "preventing" him from 2-up riding on his bike, at least until some time passes and he has experience riding. Also, he might prefer the more aggressive look of a solo rider than a brat.

Obviously, he would have the bike for a very long time, so 2-up would become practical, but hopefully by then, he'll have a stable full from which to choose. This was my approach with my boys, and I have no regrets. Besides, he can always change the seat later.

My $0.05 worth (which isn't usually worth a penny to most).

Cal,

That's a really good point. I think I will think on it some more, but a solo seat for now is a good choice to discourage 2-up riding until he has more seat time.

[SOHC4 Cafe Racer Fan]

I'd vote for option number 2. If the DCC price is a bit hard to swallow, Motolana has a similar seat thats a bit cheaper but looks every bit as nice

I really like the look of the DCC seat on #2 (it has a GREAT shape), but I was discouraged by Jojo's experience with mounting the seat, since the base is made out of ABS plastic, and does not provide a very rigid base for mounting to the frame rails.  Jojo ended up riviting metal to the seat base so it would be sturdy enough to mount to the frame.

I guess I'll have more time to think about it, since I need to focus on my K2 Bionic Mongrel build first.  For now, I am just gathering parts for this build.

[SOHC4 Cafe Racer Fan]

I'd vote for option number 2. If the DCC price is a bit hard to swallow, Motolana has a similar seat thats a bit cheaper but looks every bit as nice

Thanks, gheorghe.  I previously overlooked the Motolanna seat.  It looks nearly identical to the DCC and much cheaper.  It might be sturdier since it is built on a fiberglass base instead of ABS plastic, too.  I'll look into it some more.  http://www.motolanna.com/ourshop/prod_1910098-Seat-Cafe-Racer-v30.html

[Bankerdanny]

I really like this seat from Witchey. It works best with the 77-78 K style tank as it matches the contours, but even with an F tank I think it's a great looking seat.

http://www.ebay.com/itm/151231727530

[SOHC4 Cafe Racer Fan]

I really like this seat from Witchey. It works best with the 77-78 K style tank as it matches the contours, but even with an F tank I think it's a great looking seat.

http://www.ebay.com/itm/151231727530

That's a good looking seat.  Similar to what I've seen on HD flat trackers.

[SOHC4 Cafe Racer Fan]

Gathering more parts in preparation.

Cycle X gasket kit
Regulator/rectifier
ProTaper clutch perch

Thinking of what type of gauge - Acewell, Speedhut or something else - and rear sets

[SOHC4 Cafe Racer Fan]

Thinking of what type of gauge - Acewell, Speedhut or something else - and rear sets

How about something like this? Just arrived today along with my bar end m-Blaze discs.

That Motogadget gear is pure bike porn!! 

[SOHC4 Cafe Racer Fan]

I've been pretty happy with my spin-off oil filter from Cycle X on my 750, so I decided to pick up one for this project.

Another decision will be which type of exhaust to run on this bike.  Lately I've been thinking of a 4-4 reverse megaphone set up, but the trick with that set up will be to get an aggressive enough sound but with a civilized baffle to not scare the neighbors.

[SOHC4 Cafe Racer Fan]

Collected some additional parts for the bike:  Gasket set from Cycle X, Reg/Rectifier and Motogadget M-Unit and M-Button.

[SOHC4 Cafe Racer Fan]

Another decision will be which type of exhaust to run on this bike.  Lately I've been thinking of a 4-4 reverse megaphone set up, but the trick with that set up will be to get an aggressive enough sound but with a civilized baffle to not scare the neighbors.

How about picking up just a 4:1 header, then using a reverse cone ala FunJimmy? Inserting a straight pipe section from the collector would allow you to position the silencer anywhere you determine it needs to go. His interceptor has nailed that look and I bet it sounds the Bee's Knees.

If you could get just the header from a local custom shop, ya know, then build your own tail section.

Fortunately, time is on my side with this build, but I do like FJ's set up. That said, I haven't seen anyone run 4-4 reverse megaphones on a 550. Decisions decisions.