Topic: A New Question About CB500K vs. CB550K For TT and Anyone Else With Input

[bill440cars]

      My question concerns the "Handling of the 500 vs the 550" Nothing to do with anything else. So, let's don't go into the motor or trans. Just the "Frame and related parts", okay?

      It was brought to my attention, on a another site, from a reputable source, that the 500 was said to handle better than the 550 and was more agile and such. It was also said that the 500 was actually built closer to follow the 350F & 400F, while the 550 & 650 were built more like the 750. Because of this info, it was suggested that I might want to rethink building a 550 cafe using the 550 frame and substitute a 500 frame instead. I want to know if there is THAT much difference, if it's mostly a weight difference, if it has to do with the trail of the forks (& if the 500 forks are somehow better), if it's a combination of things or what? I'd appreciate input from experience and/or knowledge with the 2 models. Or, if you feel that you've got a pretty educated guess, let's here it. I'm wondering if the fact that I'm trimming the unneeded brackets and tabs off of the frame, getting tapered steering head bearings and having the swing arm done by Mark (HondaMan) would help the 550 frame handling? As I said, input is invited.  Thank you.

                                                      Later on, Bill    

[TwoTired]

Perhaps I'm not qualified to comment, as I haven't actually ridden my 500.  But, I would be surprised if there was a significant difference in basic handling traits.  It seems Honda didn't know about it either.

Item       /  CB500      / CB550k0     / Cb550 k3
Weight    / 403.5lb     / 423 lb        / 426 lb
Whl Base / 55.5 In     / 55.5 in       / 55.5 in
Caster     / 64 Degrees / 64 degrees / 64 degrees
Trail        / 4.1 in        / 4.1 in        / 4.1 in
Fr tire     / 3.25 19    / 3.25 19      / 3.25 19
Rr Tire    / 3.50 18     / 3.75 18     / 3.75 18

So, it's basically a rear tire width difference, and an extra 20 lbs.

Now, what also changed was sprocket ratios, and the internal transmission gear ratios.  Both the primary reduction and the final drive ratio was quite different. These later differences, while not frame handling issues, could certainly change the engine response feel going through the twisties.

One of the reasons why I hold on to my CB500 is because all the frame features (spares) appear to be the same as my 74 CB550.  I haven't found any differences yet.  Forks, yes, frame no.  (The forks are different internally, external length and travel are the same.) But, I should probably add that I have not made detailed measurements, either.

Cheers,

[bwaller]

I agree with TT that Honda probably didn't plan on any significant differences in handling between the two. I'm working to finish up my middle weight project, and in the process have ended up with several bikes, 500 & 550, mostly for spares from different years. Swingarms were unchanged, fork setups did change somewhat but again not steering geometry.

I don't see where you'd be at a disadvantage starting a build with a 550 frame. If you're looking for improvements in handling etc. this is achievable certainly and you're starting off on the right track with the things you have mentioned.

Keep us posted

[bill440cars]

      Thanks for the responses TT and bwaller,

                         I was talking with Ed over on SohcCBs and he has a friend with a CB500 that he said was a whole different feeling than the 550 and that is why I'm asking. I need to go for now but, trust me, I'll be back.

                                                        Later on, Bill


                          Told ya I'd be back! Ed told me that he'd check back with his friend to see if he had any details on why he says the 500 handles better than the 550. The way I see it, there might be some info obtained that might benefit those of us who have these 2 models. Mine aren't running yet, so I can't compare them to try to see how different they might handle.         

[SteveD CB500F]

Bill.

At one stage I had both 500 and 550(K) and I think the difference is in the seat height and hence the feel of the bike rather than the handling.  The 550 had a higher (thicker) seat and felt "taller". Only about 1/2 inch but still took some getting used to when swapping from bike to bike.

[bryanj]

Early 550 frame has same part number as all 500 frames so it can only be the "Add ons" that make it feel different, Maybe the F and K3 were different but not the K0-2 (not that we had those in UK but i have ridden a few US imports!)

[bill440cars]

     
           Thanks Steve, for that bit of info. Amazing how some seemingly little things can change the feel of things, isn't it? Every bit of info will help and is appreciated


           Bryan, now that you mention it, I do remember that the 550 frames changed in the area where the footrests and mufflers attach were changed for 77' for sure. I'm not sure if there were any other changes or not though. Thanks for your input on this.

                                                      Later on, Bill

[bill440cars]

Early 550 frame has same part number as all 500 frames so it can only be the "Add ons" that make it feel different, Maybe the F and K3 were different but not the K0-2 (not that we had those in UK but i have ridden a few US imports!)

       After reading what Bryan had posted, I wondered just how far Honda went with the frames AND the swingarms. So, I decided to see just exactly which years of those 2 bikes shared which parts. No disrespect or disbelief to what Bryan had posted either. Here's what I found:
                                                       FRAME
          Model:                    P/N:                                      Year:
          CB500K         50100-323-674B                             71'-73'
          CB550K          "         "        "                              74'-75'
          CB550K         50100-374-710ZA                              76'
          CB550K         50100-404-670ZA                           77'-78'
           
                                                    SWINGARM
          CB500K         52100-323-040B                             71'-73'     
          CB550K          "        "        "                               74'-75'
          CB550K         52110-374-700ZA                              76'
          CB550K         52110-404-670ZA                           77'-78'

         So the CB500K shared the same frame with the 74'-75' CB550K just like Bryan said AND also the swingarm! Then the 76' CB550K seems to have a frame & swingarm P/N seperate from the others, while the 77' & 78' CB550k had yet another set of frame & swingarm P/Ns  Now, if I could just find out what the differences are.

                                                   Later on, Bill  

[TwoTired]

I don't have a 76 CB550K.

But, they added a grease fitting to the swing arm that year.  I don't see any other differences between the 77 Swing arm and the 75 Swing arm.

The 77 frame moved the location of the side stand mount rearward from those on the 500-550K 75 and earlier.  Maybe the 76 as well?

Also, the muffler/ rear foot peg mount feature for the frame changed in 77.  The ignition switch location changed from frame mount to tree mount for 77-78, too.

Cheers,

[bill440cars]

               Another question has come to mind. Wouldn't a shorter wheelbase provide better handling?
        Wouldn't the bike be more agile and more manuverable? If so, I know that the 750 swingarm is
        shorter and I think I remember someone (sometime back) using one on a 500 or a 550. I'm
        presently trying to find out how much shorter the 750 swingarm is, compared to the 500/550
        swingarm. This might be an answer to give the 500/550 (& even the 650, it it will fit it too) an
        improvement in handling for the "Twisties" or whatever. Any thoughts or input invited.

                                                             Later on, Bill

[SteveD CB500F]

Bill - they're barely stable at high speed (relative, I know) with a standard swingarm.

Shorten the wheelbase at your peril!

[78 k550]

got both bike's i think they handle very simillar.

Paul

[bill440cars]

Bill - they're barely stable at high speed (relative, I know) with a standard swingarm.

Shorten the wheelbase at your peril!

Hey Steve,
           So it seems pointless to try to shorten the wheelbase (that might make it more manuverable), it I have to add a steering damper. But, from what you're saying, it sounds like it could stand to have one, no matter what I do. Decisions, decisions.

           Does anybody have a 550 that handles well through the "twisties" and flat out? If so, would you mind sharing what you did to accomplish it? Keep in mind that I'm trimming the unnecessary brackets & tabs (to trim some weight), getting & installing tapered steering bearings, installing Boge rear shocks and getting the swingarm done by HondaMan. Is there something I'm missing or just plain don't know about?
                                                Later on,  Bill

          Thanks for that Paul. Every bit helps.

[crazypj]

Fit longer heavier sprung rear shocks, tightens up steering ( I used CB750 K series on 550 F1)
Fit decent fork springs, I find all 550/500 too soft on front end. CB400 F bars, lower and narrower, ok for around 350~400 miles a day
The K series 550 have different side stand placement compared to the F and it can drag on the ground.
Usually get a speed weave around 115~118 mph but it goes away at 120 or more ( yes, its modified a bit)
PJ

[SteveD CB500F]

I have two 500s.

One has Hagon shocks and modern Avon Roadrunner tyres.  Handles OK.
One has stock (old) shocks and old Bridgestones. Handles like a 35 year old bike!

Without compromising the "look" of the old girl, shocks and tyres did it for me.

[78 k550]

My friend has a 72 500 and I put a set of 750 shocks on 13 1/4 i think. He was also a few years ago 120 pounds heaver. He has a new pair of S-11's on the rear there some great tire's for that buke.

Paul

[bryanj]

Best ever handling Dunlop TT 100's but they dont last long plus Koni shocks and most important play about with tyre pressures to suit your individual weight and riding style. 1 1/2 psi up or down makes a difference--just remember to always make the alteration at the same temperature!

[bill440cars]

Fit longer heavier sprung rear shocks, tightens up steering ( I used CB750 K series on 550 F1)
Fit decent fork springs, I find all 550/500 too soft on front end. CB400 F bars, lower and narrower, ok for around 350~400 miles a day
The K series 550 have different side stand placement compared to the F and it can drag on the ground.
Usually get a speed weave around 115~118 mph but it goes away at 120 or more ( yes, its modified a bit)
PJ

           Hey PJ, Man, I meant to touch base with YOU on this too and I guess I got sidetracked or something.   Sorry about that guy.   I figured you'd have some input. About rear shocks, what about the new Boge shocks that I have? I totally agree on those bars (or something similar), I just can't take getting down on very low handlebars. My body wasn't built to do that and, as I'm getting older, isn't getting any better. On the forks, are there other Honda fork springs that would work or does a person just need o buck up and get some Progressive springs (or something similar)? Or would it be possible to do a slight preload on the original springs? Understand, some of us work on a very tight budget. Take care guy.

           Again, any input from you all is greatly appreciated (from the slightest thing, to an extensive amount) and if I don't personally mention an individual who has provided something from experience
or whatever, I really do appreciate it and am going to take ALL input into consideration.

                                                         Later on, Bill