Topic: My 550/650 Project

[Tommy Neimeyer]

Like most everybody else, I've got a project bike, actually too many project bikes.  The one I am mostly working on is a CB500.  It is real early in the project, just a rolling chassis and about 4 or 5 various motors littering the floor.  Eventually, I hope to have a bored 650 in it but for now, I will use a 550 motor to sort things out.

In these pics, the chassis has been powder coated, a CBX swingarm fitted, CB900F 39mm forks and wheels from a Honda Hurricane.  I have since removed the wheels, blasted, painted and started polishing the rim lips.  There is a long way to go but with everyones help and suggestions, we'll make it.

[gnanner79]

How wide is the rear rim?  Have you installed the engine to make sure the rear sprocket lines up with the front sproket?  I was going to put CB600F2 rims on my CB550, but the rear sprocket stuck out about an inch further than the front sprocket.  I talked to a guy at Ohio Cafe Racers and he said the rear cush drive could be milled down, but other people I talked to said that it was only safe to really mill it down about a 1/2 inch.  I'm just telling you this so you don't get too far down the road and realize the rear wheel doesn't really fit.

Cheers,
Shawn

[Tommy Neimeyer]

Shawn,
  Thanks for the comments.  I have installed a "thinner" hub but have not yet put in a engine to verify alignment.  The main problem I am having is centering the wheel.  Worked with it today and I think I have it worked out.  The rim is 3.5" which is narrower than a F2/F3 wheel.  I also changed swingarms to a JMC arm.  I will try to get a pic up Tuesday.

[Kevin400F]

Hi Tom, what size tire are you planning to run?   I'm not sure how the old chassis would get along with radials, so I assume you'll be on high-perf bias-ply rubber.   

As a point of reference, my stock 550 with 110/90-18 on the OEM 1.85 rim has approximately an inch of clearance between the 530 chain and the tire sidewall.  A 130 (depending on tire brand) sould have about 3/4" to 5/8" clearance, I reckon.

Kevin

[Tommy Neimeyer]

Kevin,
  I will run either a 140 or 150 on the rear.  Not sure what brand, size or belting I will run, there are several options available.

Today, I put a empty case with a output shaft in the frame.  I will have the wheel carrier cut down about 3/8" and things should align.

I was told that there are also offset front sprockets available but I do not know from where.  If anybody knows the manufacturer let me know.

Still working on getting the wheels polished.  Front is finished, rear needs more sanding.  It's very tough on the hands but worth it.

Cheers, Tom

[Tommy Neimeyer]

Latest pics with the JMC swingarm.  I had to make a tool for the adjusters, not sure if I like them, just will take some time to get used to.  I used a couple of piston pins welded into a piece of 1" square tube.

Still need to polish a little more on the wheels.

Cheers, Tom

[bill440cars]

                     Tom, That's quite an impressive start you've shown there, can't wait to see how this
          one comes out. I'm gathering up parts to build a 550 myself but, my parts aren't quite as
          impressive as yours. I've got a pair of Comstars from a 650, a set of forks with the front brake
          system from an 83' VT750C (39mm also, plus, it's got a factory fork brace to boot). I've got
          to either trim off the tripletree stem or swap it with one from the 550. (thought about,
          grinding the weld off of the stem, drop it down as far as I need, cut off the excess and weld
          it in place), get me another brake rotor to finish the front. If it hadn't of been for Terry
          (cb650), I wouldn't have the VT parts or the front Comstar. I've got to do like you did and
          check the sprocket alignment also. I've got an unfinished cafe style seat from Jorge (550ko)
          and I've got to finish the seat. I'll be keeping an eye on your progress, Tom and Pauls'
          (paulages) progress because I too want to build a decent Cafe style bike with a 650 but, like
           Paul, I want to build a 650 with the look of a 500 or 550. As soon as I can I'll try to take
           some pictures and put them up. Again Tom, that is quite a start you've got, can't wait to
           see more. It's really unbelievable how many talented and knowledgable people there are on
           this site and it just keeps growing!    Awesome!           Later on, Bill

[dusterdude]

i need some educatin here,what is the deal with the cush drive?can the sprocket not be mounted solid to the rim?if not,why?

[Tommy Neimeyer]

If you had a solid wheel, the sprocket could be bolted to the wheel but it would be more voilent when shifting both up and down.  I would guess the rear wheel would "break loose" more often as the rubber cushions the engine force to the drive train.  Also, I think wear and tear on drive line components would increase.

For instance when you are headed into a corner and downshift, if the revs are not matched close, without a cush, the force of the rear wheel action is transfered to the engine output shaft instead of being dampened.  This could result in bearing and gear wear beyond normal design.

I see no easy way to mount the sprocket to the wheel, at least not these wheels.

Cheers, Tom

[dusterdude]

tom,i understand the thought processes involved,but ive owned harleys for 25 years and they use solid mounted sprockets and ive never noticed any ill handling from them at all.

[Tommy Neimeyer]

I went out reading some more and everything pointed to the reasoning behind the cush is to dampen the drive line power.  Why Harleys do not use them is kinda up in the air.  However, most clutches also have driveline dampening qualities.  The Harley may have the dampening effect designed into the clutch and not need any in the rear wheel.

Most sources think, no cush will increase drive train wear even to the point of damaging teeth on transmission gears.

Cheers, Tom

[dusterdude]

the clutch idea is possible as i dont know if that what harley does or not.gives me something to ponder.

[Kevin400F]

Tom, as you make progress on the engine side of your project, keep an eye out for a useable stock 550 camshaft.

I'm sorting through parts and pieces of two 550 engines we got from you previously, but it looks like both cams may have problems.  The one from the engine with the broken cam chain has a couple of lobes with light spalling.  They might be OK with a little cleanup...maybe I'll bring it over one of these days have you take a look.  This morning I pulled the cam from the engine with the self-destructing transmission, and it has some rough lobes as well (this engine had some metal circulating in the oil as a result of the bottom-end problems.  In case, the cam isn't a critical path item.....once I inspect the bottom end of the "good" engine for any issues and declare it fit for service, I need to order a gasket set, cam chain and tensioner blade and assemble the engine up as far as the head.  Slipping a good cam in place and landing the rockers/head cover is a piece of cake at that point.

Regards,

Kevin

[bryanj]

Kevin All teh 500/550 have the same cam so there are lots out there (at least 10 in my garage SOMEWHERE!)

[Tommy Neimeyer]

Kevin,
  I'm pretty sure I have a 500 cam available, will look on next off days and e-mail you.  If I have one, it's yours.

The question I have is can the 650 cam be used in a 500/550?  I thought I read somewqhere that it can be used by just changing the timing chain gear, however, it will cause the tach to read improperly.  Can anybody verify this?

Cheers, Tom

[SenorSol]

I know it's been a long while since this thread was first posted, but what year/bike did the swingarm come off of?  I'm looking for a slightly longer swingarm for my 73 cb500, a direct bolt-on change would be nice.

thanks