Author Topic: CB550 Track Bike (Read 40930 times)

Rocketman · « **Reply #25 on:** December 01, 2013, 05:57:51 PM »

Franken, Thanks for the links. Nice work. Want to read the entire post when I have a little more time.
The wheels are back from Buchanan's. Wow do they look nice! Still in sticker shock, but they are beautiful. Did some trial fitting to get an idea of what the finished project will look like. Also picked up a frame loop that fits the seat nicely.

Rocketman · « **Reply #26 on:** December 10, 2013, 07:00:22 PM »

Haven't made much progress on the motor. I have a set of black rod bearings on order. They are the thickest bearings and should get me within the normal clearance range. Using plastigage to double check my clearances as I don't trust my ability to get accurate measurements with micrometers.
I did have the damper rods shortend to bring the travel down from 152 mm to 121 mm, which is stock. The fork tubes still extend above the triple tree by 2". I'll wait until I know what the rake and trail are before considering shortening the tubes.
The gas tank has been coated with Caswell Epoxy. Went with the dragon red and am glad I did. After putting it in the tank, rolling it around, then draining it there were still parts of the tank that were not coated. Poured it back in the tank, did it again, and made sure it was completely coated.
The tires arrived. Decided on Heidenau Racing Tires for now. I know Avon are the standard, but Heidenau sure look like the Dunlop KR tires used back in the day. Put a K65R 100/90-18 on the rear and a K44R 90/90-18on the front. The rear may be a little narrow, but should be fine for working out the bugs and testing.
Also ordered in a set of IKON shocks. Had the bodies painted silver to match what Honda used in the 60's. Lots of progress in general, but need those rod bearings. May have to order from CMSL if Partzilla doesn't come through soon.
Here are a few more pictures.

Rocketman · « **Reply #27 on:** December 11, 2013, 07:41:57 PM »

My wife is working this evening which allowed me to play in the shop. She always knows where to find me.

Worked on the front fender. I picked up a aluminum fender out of Germany through the US distributor The Vintage Spoke. It looks like an excellent fit with no mods. Sourced aluminum plate and rod through Aircraft Spruce for the bracket and stays. Used some artist paper to make a template for the bracket. It is heavy enough to bolt to the forks to get it right the first time. Once satisfied I traced the outline on the aluminum plate and went at it with a metal blade in the jigsaw. Used a 1/2" bit to drill the corners of the cut outs, then cut between the holes with the jigsaw. Used a rotary file in the drill and files to straighten up the cut outs. All in all it turned out pretty good for hand tools. Next step is to bend it around some pipe, drill the mounting holes, and finish it up. Here are some pictures of the fender mocked up and making the bracket.

SOHC4 Cafe Racer Fan · « **Reply #28 on:** December 11, 2013, 08:57:18 PM »

Damn that's cool.

TheAngryTexan · « **Reply #29 on:** December 11, 2013, 09:38:27 PM »

I really like the sound of this one! I look forward to the engine build-up..

Rocketman · « **Reply #30 on:** December 14, 2013, 06:52:50 PM »

More progress to report on the front fender. Found a plastic pipe fitting that was just the right diameter for forming the bracket around. Clamped it in the vise and went at it with a heavy brass hammer and a block of wood to keep the hammer marks on the aluminum to a minimum. As I expected the areas that were cut out formed around the pipe easily. The sections that were full width resisted bending. Found that by laying those sections over the open vise and tapping with a ball peen hammer they would curve. It did dimple the inside which will not be visible, but also left corresponding raised dimples on the outside. The good news is a file quickly smoothed them out. Still have one problem to solve. The bracket not only needs to curve side to side over the fender, but front to back to lay flat on the fender. As it currently sits the front and trailing edge of the bracket sits about 2 to 3mm off the fender. One thought is to take an old steel fender, bolt the bracket to it, and see if I can pursued it to fit. Will need to round up a fender at the local motorcycle salvage yard and think about it some more. Don't want to mess up what I have so far. Here are some pictures.

calj737 · « **Reply #31 on:** December 15, 2013, 05:04:51 AM »

If you can't get the fender to "shrink" front to back using heat and dolly, then you might need to split it down the side-side centerline, and then re-weld it. Essentially, making a small relief cut to move the outer edges towards each other.

Or, depending upon how far above the rear edge oft he fender, make a small relief cut just below the back of the fender, from rear toward front, then shrink it that direction and re-weld.

Make sense? Or am I telling you what you already know? Seems a bit rhetorical suggesting anything yo you as your skills are obviously very high!

Vertical cool looking project.

Rocketman · « **Reply #32 on:** December 15, 2013, 11:11:39 AM »

Calj737, Appreciate the suggestions as I had not thought of cutting and re-welding. Visiting with a buddy tonight who's a skilled body man to see if he has any suggestions or experience shrinking aluminum. Thanks.

SOHC4 Cafe Racer Fan · « **Reply #33 on:** December 15, 2013, 02:18:17 PM »

Rocketman,

I'm thinking of adapting a 750 SS tank to a 550. Do you have any detailed measurements on how you had to modify your CR750 tank to fit onto your 550 frame? I'm wondering what the most efficient way to do this is.

Roach Carver · « **Reply #34 on:** December 15, 2013, 05:15:56 PM »

Very nice work

Rocketman · « **Reply #35 on:** December 18, 2013, 05:51:09 PM »

Cafe Racer fan,

I did not measure the before tunnel of my Airtech CR750 tank before I started. I also don't have a stock 750 or stock 550 tank to compare it to, so not sure of the differences. The backbone of the frame on a CB550 must be larger than the CB750 as the Airtech tank would not fit the bike until the tunnel was enlarged. I had to both increase the tunnel width and height to fit the CB550. The good news is both tanks fit the front mounting point, but I did have to cut the rubber cushions width in half to fit the 750 tank. Sorry I am not more help.

SOHC4 Cafe Racer Fan · « **Reply #36 on:** December 18, 2013, 09:26:57 PM »

Quote from: Rocketman on December 18, 2013, 05:51:09 PM

Cafe Racer fan,

I did not measure the before tunnel of my Airtech CR750 tank before I started. I also don't have a stock 750 or stock 550 tank to compare it to, so not sure of the differences. The backbone of the frame on a CB550 must be larger than the CB750 as the Airtech tank would not fit the bike until the tunnel was enlarged. I had to both increase the tunnel width and height to fit the CB550. The good news is both tanks fit the front mounting point, but I did have to cut the rubber cushions width in half to fit the 750 tank. Sorry I am not more help.

Thanks for the response. Now I have an idea of the fab required.

Rocketman · « **Reply #37 on:** December 22, 2013, 06:31:30 PM »

More progress to report on the fender. Decided the best way to create the front to back curve in the fender bracket was by cutting slots in it. I went at it with my Dremel and cut off disks cutting slots on each side approximately 1/2 inch in length. The bracket was then supported by a wooden form and a hammer used to bend each of the individual "fingers" down. Once I had the shape set it was off to the welder. I was concerned the .080 thickness of the bracket would be difficult to weld, but my concerns were unfounded.

Once back in the shop I used rasps and files to smooth everything back out. The next step was to locate the fender to the bracket. I had some clamps that were just the ticket and in short order 4 holes were drilled. For now I am using bolts to hold the fender to the bracket, but will use rivits for the finished product. Drilling the holes to mount the bracket to the fork legs was a leap of faith, but I took a deep breath and did one side. I did not want to screw it up at this point as I did not want to make another bracket. After bolting the bracket to the right fork leg I was able to locate the holes for the left fork leg and drill them. Here are some more photos. If you know where to look it is not perfectly symetrical, but not bad for a first effort. Still working on the stays. Tried to make them out of 2024 aluminum, but when I crushed the ends in the vice the metal fractures along the edges. May need to use a more malleable aluminum.

I broke down and order a second set of rod bearings from CMSL as they had them in stock. Hope to get to the motor in January.

Just4fun · « **Reply #38 on:** December 22, 2013, 09:47:55 PM »

I have been thinking about using upside down forks on a project. How to mount a vintage style fender is a key consideration. I appreciate you taking the time to document your build.

Sent from my iPad using Tapatalk HD

calj737 · « **Reply #39 on:** December 23, 2013, 05:57:30 AM »

Rocketman - Dang! I thought proposing cuts would make it clear on how to simply cut it. You took it to a whole other level with the kerf cuts...

Either way, it has turned out very well.

My input was: A small "pie" from the back edge thru the oval on both sides would have allowed you to warp the shape and shrink the length. Two cuts, two welds, less filing.... Always impresses me how detail oriented folks not his forum are and the lengths they go to when making beautiful bikes.

I am impressed and envious.

Rocketman · « **Reply #40 on:** December 24, 2013, 09:13:06 AM »

The fender bracket is definitely a work in progress. I appreciate everyone's feedback. If anyone needs a 18 inch aluminum front fender check out http://www.kedo.de/ . They ship through a US distributor. Checked with a machinist Friend and he suggested hardware store aluminum tubing for the stays. Apparently it is generally very malleable and what he used on a past project. The aluminum sheet is available through http://www.aircraftspruce.com/ . Wishing everyone a Merry Christmas and a Happy New Year!

IBleedHondaRed · « **Reply #41 on:** December 26, 2013, 08:51:26 AM »

why throw them in the scrap metal pile? who's team are you on here?

Rocketman · « **Reply #42 on:** January 02, 2014, 06:33:45 PM »

Had a great New Years Day which included spending the afternoon in the shop. Have the fender fabricated, next is paint and assembling. Found the tubing I needed to make the stays at Zoro Tools, www.zorotools.com . They carry a nice selection of aluminum at reasonable prices. I used 3003 3/8" tubing and it formed without cracking. I found that I needed some blocks of wood in the vice to smooth out the bends from the vice jaw edges.

I scored some Yamaha R1 footpeg assemblys on eBay. Cutting the brackets down left them in what appears to be just the right position. I have found the dimensions of the CB550 to be nearly identical to my last race bike and am using it as a reference.

At this time I am planning to use CB750 carbs. I found a reference to a difference in the early versus late intake manifolds. Searching the parts manual showed the 77 & 78 manifolds have a different part number. I found a set on eBay and they are infact different from the 76 and earlier manifolds. The easiest way to tell them apart is the late manifolds are much shorter. More importantly, the late manifolds are in nearly a perfect alignment with the CB 750 carbs. You can see the difference in the photos.

Rocketman · « **Reply #43 on:** January 05, 2014, 07:02:21 PM »

Working on the brakes today. Made the template for the front brake stay and the anchor for the rear brake cable on the drum. Trying to get all the mounts fabricated for one trip to the welder. The upholsterer called and the suede finally arrived. Hope to have the seat back this month. So many details!

Also posting an old racing photo from 1975. The motorcycle is a TD2 Yamaha. My mother is on the left and father on the right. I'm the dude in the mesh muscle shirt. Hard to believe that was nearly 40 years ago.

bwaller · « **Reply #44 on:** January 05, 2014, 07:39:02 PM »

Cool pic but my tinitis rings a little louder every time I see stingers.

Rocketman · « **Reply #45 on:** January 06, 2014, 07:18:38 AM »

Can't tell you how many nights after a day at the track I went to bed with ringing in the ears. I later wised up and used foam earplugs. Fortunately no hearing loss to date! One of my favorite sayings is "To be old and wise, you must first be young and foolish."

Bankerdanny · « **Reply #46 on:** January 06, 2014, 09:10:05 AM »

Yep, that would be the 70's alright.

SOHC4 Cafe Racer Fan · « **Reply #47 on:** January 06, 2014, 09:15:01 AM »

That TD is sweet. Not so much as to the mesh tank top!

KrautKoffin · « **Reply #48 on:** January 06, 2014, 12:29:09 PM »

Looks like you stole number 10's bike and some sharpies!

Rocketman · « **Reply #49 on:** January 12, 2014, 05:49:31 PM »

Racing was pretty laid back then. My "leathers" consisted of a black suede jacket and brown leather pants! The good old days.

Had the brackets for the foot pegs and frame loop welded Saturday. Used some all thread to hold them in place and ensure they were square and level.

Made some plates to cover the opening under the frame loop.

Also had the brake cable anchor welded to the backing plate.

The rod bearings arrived from CMNSL. First I need to Tear down a buddy's RD400 for a crank rebuild. Pulled the motor Saturday afternoon and have it sitting on the bench. Should only take a few hours, you got to love the simplicity of a 2 stroke. Once the crank is shipped time to start building my motor.

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Author Topic: CB550 Track Bike (Read 40930 times)