Topic: Hunter's 1975 cb550 project

[Hunter S]

Hello everyone I gave my intro in the new members section not long ago so there is some info about the bike there. Long story short is I bought this bike for cheap when the previous owner removed the handle bars and unhooked the wiring harness then gave up on the bike. I got it home plugged the harness back up and gave the battery a charge and it fired to life! Ok now that I know the bike runs its time to tear it down. Just want to add the bike only has a little over 13,000 miles on it. This is what it looked like when I got it home.

[Hunter S]

I already bought some stuff for the bike as I have an idea of the direction I want to go with it even though I still haven't got every last detail worked out. Thats where you guys come in! This  will be my first build so I will be open to suggestions and constructive criticism. So on to the parts. What you are looking at in the pics is a Hotwings dirt tracker seat and pad and a fork assembly from an '08 gsxr 1000.

[Hunter S]

Got the exhaust pulled off as well as the side stand and center stand and a few other odds and ends. Some stuff will not go back on so I will be grinding some mounts off the frame and smoothing things out when the time comes.

[Hunter S]

Undecided on a paint scheme but I have this one stuck in my head. As a kid I always loved seeing Bubba Shobert, Kenny Roberts and Jay Springsteen in the monthly cycle magazines and I loved those red white and blue Hondas!

[calj737]

It's a shame that the bike itself looks to be in very good condition to be a "donor". Lots of sought after parts on that bike that you won't be using too.

Swapping to a GSXR front end is fairly easy to do these days. Cognitomoto sells a conversion hub to lace to CB rim, but uses stock GSXR rotors, calipers, axle, and forks. They even offer some custom triples and top clamps too.

If you are pursuing a "tracker" style, I'd suggest bars not clip ons.

You'll discover the stock 550 seat hoop has curvature to it from the tank to the shock mounts. It's pretty difficult to disguise it with aftermarket seat cowls. You may be better off having it cut, re-welded with a custom hoop, and flattened out. But this needs to be done someone competent with a welder and using quality tubing.

Carefully disassemble your bike, and save everything. You'd be surprised as to the usablilty of the spares since not all of these parts are made any longer.

[SOHC4 Cafe Racer Fan]

You will need to tap the upper tree clamp and attach bar mounts. Not a huge thing.

Also, you may need to re spring the forks when you are complete since the bike may weigh less than a GSXR.

[Hunter S]

Calj737 you are right the bike is in pretty good shape and would be a great candidate for a restoration but I never intended to go that route. The good thing is the spare parts will benefit the members here as I plan to sell all the left overs in the classifieds. I have been looking at the Cognimoto stuff and that front hub is one of my next purchases. I like the idea of using a top clamp so I can use stadard bars. I will look into those more over at cognimotos website. I do want a bike that is comfortable to ride for long periods of time so that may be just the ticket. We shall see. You are right that aftermarket piece dont fit the stock seat hoop that great, an aftermarket hoop may be in order.
 CB750 cafe racer fan you are right. These forks will definately need something. This bike is going to weigh even less than a stock cb550.

[calj737]

May not weigh less... It might, but GSXR forks, new triples, and Cognito hub with dual discs, calipers etc, adds more weight than you think. One thing is for certain, it will handle better and stop better, so stronger triples are recommended. Tapered stem bearings too for the neck.

[Hunter S]

One thing is for sure those gsxr fork tubes are beefy! Should not have a problem with flex. Neck bearings will come from All Balls.

[calj737]

Yeah, this flex isn't from the forks, it's from the neck/frame of the stock bike. Understand you're transmitting greater force now than was designed. It's recommended to inspect the stock frame carefully around the neck and frame tube connections. These were riveted and pinch welded from the factory. Modern frames are quite differently fabricated.

[Hunter S]

Agreed. I will be doing some research on what areas to do some reinforcing to the frame.

[SOHC4 Cafe Racer Fan]

Hunter,

Cal is right about the flex.  The 550 has a stamped frame and the frame welds are not very robust.  It would not be a bad idea to reinforce the welds to the head stock.  If you have access to a welder, you may even gusset the triangle areas of the frame (see the circled areas below).  It is not necessary, but it may help.  Just know that when you strengthen portions of the frame, you will be highlighting the weaker areas.



My comment about checking the weight and re-springing is something to look at upon completion and tuning, since you'll then have an idea as to how the finished 550 compares in weight to the particular GSXR model you took the fork from.  It may end up heavier, lighter or a wash.

As for the bar mounts, Devin at Cognitomoto sells them.  I would not be surprised if you purchased a top clamp and the risers if Devin would not tap the clamp/mount them for you for a little extra. Devin is a great guy to deal with.

http://cognitomoto.com/collections/cockpit/products/rise-clamps-7-8-bar