Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: neat street on October 06, 2025, 04:08:01 PM
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Hi all, the clutch on my 500 is `very stiff`, I have had the clutch appart 5 times and re-assembled and still the same (checked springs and all well in tollerance, all torqued to correct values ect) adjuster works well and smooth. Cable I believe is routed correctly as per an earlier post (not mine :-)) and advised by Nurse Julie. You almost need two hands to opperate the clutch? the 750 I have is nice and easy as a comparison. cable is new (came with the bike) and runs very free. Any help/advise would be appreciated, thank you.
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My 500 has the long pushrod with the adjustment screw in the left side casing if yours is the same have you checked the spiral screw arrangement that has that alloy screw. You can get a lot of muck & rain in the casing.
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Are you sure the cable isn't frayed somewhere inside?
How is the cable operation when removed from the clutch adjuster, smooth or can you feel any resistance, how old is the cable?
Doesn't the 550 suffer with clutch pushrod problems of is that the 500?
If you want to experiance a stiff clutch as standard try a Laverda Jota, stiff isn't the word :-(.
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If the push rod moves freely
The worm drive on the LH side casing is well greased,and moves easily, please check the cable
My 500 has the standard set up and is very smooth and light,
Sent from my SM-A546E using Tapatalk
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Most common fault is bad cable or an original one that has been lubed! Lube swells the linings on the inner and inside the outer.
Second most common is the worm scre siezing or ball bearing missing
Third is some idiotic po has fitted stronger springs
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Or the push rod is broken. It should be one long rod not in 2 or more pieces.
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Thank you all very much for your replies.
Ted, the ajustment on the left hand side completly stripped cleaned and greased and works well.
Dave, the cable is new and runs nice so no fraying.
John, the side `screw`/worm drive is perfect and moves like a clock, was stuck before I stripped and cleaned, but now realy nice and smooth (well greased).
Brian, as above, worm drive works well, ball bearing intact, cable smooth and new, stronger springs?.. maybe, dont know how to check these, but measurements are well in spec from the workshop manual.
Ken, the push rod was broke in two but replaced on rebuild.
Thank you all very much for your help, not sure what next to try
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Just a shot in the dark, but, does the handlebar lever move freely. They are prone to collecting dirt and water, plus make sure the nut and bolt acting as the pivot have not been overtightened. Genuine Honda levers have a bush in this pivot point also. A little drop of grease here can help. Ironically, I have just renewed the clutch cable on my 400, usual procedure every couple of years as they tend to 'cook' over the top of the cylinder head. I would be tempted to fit yet another new cable, just in case, a lot less hassle than stripping down parts.
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I'm not so familiar with this mech particularly, but with others have had a wear issue with the helix material the clutch "pressure" lever works within.
With what initially appears insignificant slack between the two, it can really bind to poor effect when subjected to load by not staying true in its bore. They move easily when just that component is checked on it's own, but shft substantially as the cable pulls the component off axis under full clutch load operation.
Its something that helix arrangement are prone to if not complying with designed intentional stability.
There's differential type "Torsen" that makes use of this conflict to restrict and proportion slip by being manufactured to specified ramp angles in promoting this effect under more extreme loading. Not exactly the same as axial/radial unintentional float, but demonstrating how powerful this can be in locking the mechanism when required.
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One cheap way to test for helix binding is to use a friction "extreme" grease within it to assess in that status.
Automotive CV grease will provide one of the least binding characteristics you can easily get hold of to try it.
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One cheap way to test for helix binding is to use a friction "extreme" grease within it to assess in that status.
Automotive CV grease will provide one of the least binding characteristics you can easily get hold of to try it.
Thanks for this ideas K2-K6, also the possibility of the worm drive being the issue.. Grease check first, then try to think of a way to `load` the worm drive to see if that binds under load??? Its completetly free off load.
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TrickyMicky Just a shot in the dark, but, does the handlebar lever move freely. They are prone to collecting dirt and water, plus make sure the nut and bolt acting as the pivot have not been overtightened. Genuine Honda levers have a bush in this pivot point also. A little drop of grease here can help.
Thank you, all has been stripped and cleaned, handle moves freely and has the littlle bush, all shots in the dark welcome :-)
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To give it load you'll need to reassemble and try it with the full clutch as a test.
It's one of the useful/compromise characteristics of these type mechanism that makes them attractive .... in some applications. The differential example given above allows virtually full and free movement under low load, but ramps up considerably when subjected to load across input to output. The designers making clever use of what can be a fault in operation. The name of that device is made up of TOR-que SEN-sing to illustrate just that.
If your mech responds to change of lubricant, that would suggest either the bore or the helix (or both) have wear that allows that little but powerful shift in geometry to give a much high torque requirement across that device.
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Do you have the correct number of plates in the clutch basket?
Is the clutch adjusted correctly?
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I think I may have found the problem (Thanks K2-K6) and all others for your contributions?? what are your thoughts please and can anyone advise what part (or both) is worn and if anyone has the part/parts to replace please if required? thank you for all your help
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Do you have the correct number of plates in the clutch basket?
Is the clutch adjusted correctly?
Thanks Florence, yes, correct no of plates and did adjust acording to the manual.
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At one time Dave Silver had pattern ones but as i remembercthey were not cheap
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Thanks Brian, yes I can see some online, but very expensive, and not sure if I have to replace just one part or both? or is it correct and they are `normal` and dont need to be replaced? Although I suspect they are, or at least one of the is out of tollerance? Thank you again for your help.
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Have you any brass or copper sheet metal ? You could make a small cylindrical shim to go around that section and keep it aligned, this to test for concept/correction etc before deciding to commit much cash in buying a replacement.
Also pack it with CV black grease when assembling to try out for effective action.
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K2-K6, nothing that thin, but for test purposes, I could use a coke tin?? will try tomorrow if possible,
thank you for the idea
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K2-K6, nothing that thin, but for test purposes, I could use a coke tin?? will try tomorrow if possible,
thank you for the idea
Yes, should do the job to let you try it.
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Hi All, made a bush from 22mm copper pipe and got down to a good size to test, smooth to operate the adjuster free hand but although maybe a very slight improvement, the problem persists :-(
see pics and home made bush.
Any other ideas or are we stumped?
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My experience in regard to cable lubricant is likely at odds with some, ordinarily using silicone oil for them to good effect.
It's, essentially, inert with generally used materials in bowden cable installation. Effective in lubricating, precludes water ingress and offers no (that I've experienced) downside.
Worthwhile to evaluate in this case, as slightly puzzling it is.
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In my experience the cause of most problems on the 500 clutch setup is the cable routing. It must follow the diagram in the PDI instructions. Does yours do so?
Have you checked the operation of the mushroom in the clutch basket as well? Just to ensure it’s moving freely.
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You will have checked the below items I'm sure, just trying to think outside the box.
You have not mentioned the end ball bearing, does it have one?
Is the brass screw adjusted and locked in with the pinch bolt?
Is it a genuine clutch cable, or the correct length if its aftermarket?
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This may sound incredibly stupid, but is it possible to install the clutch system progressively to try and isolate the problem? Eg, lever; lever plus cable; lever plus cable plus scroll mechanism…..and so on and so forth.
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Thank you all for your perseverance with this for me, it is very strange... Brian did mension the clutch springs and maybe they are the `heavier` ones (can anyone measure a standard spring wire thickness to check against mine please?? ( I assume this would be the difference between a standard or `heavey duty`?)) I will double check everything again over the weekend.
Thanks again K2-K6 for your advise.
Thanks Ken, will check the cable routing again.. the `mushroom` was free, will investigate again when stripped this weekend to double check.
Thank Ted, will go through your list.. Yes does have the ball bearing inserted. the adjuster is locked with the `horse shoe` and blot, will check the cable again, I had one fitted and a `new spare` when I brought it, I used the `new spare`(after market) so can check this again for length and compare ect.
Thank you Sesman, trust me, at this stage nothing is stupid :-), After I drain the oil again and strip/check, I will try and find a way of doing things in steps and test each bit if I can.
I would assume that it would not `run in` once the bike has started? At this stage everything is still in `building mode` not had it running for more that a couple of seconds as no exhaust/tank ect fitted (dont have exhaust yet, tank needs to be completly cleaned and paint removed (viniger comming today/Monday) :-) then painted ect, lots more to do, but want to make sure everything is working as it should before investing in one of the more expensive parts, the exhaust. once I know the clutch is OK, I can move on :-)
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You say the cable came with the bike, is it the correct cable? Just because it is the same as the one on the bike doesn’t necessarily mean it’s correct, so much stuff gets changed and bodged over the years. Is it a good quality cable.
Is the angle of action/pull between the clutch actuating leaver and the cable ok, say around 90deg or just a bit more to give the best possible leverage.
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I remember a bulletin that mentioned a mark on the alloy adjuster that had to be in a certain position on the "clock" as it were, not sure if all the bulletins are readable at the moment
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I do not want to dismiss any of the excellent advice that is given in this thread and can only offer my own experience. Regarding heavy duty clutch springs. I am one of those idiots (thanks Bryan) who after lots of consideration and being fed up with slipping clutch, decided on a belt and braces approach and installed heavy duty springs from EBC, along with new plates and I can tell you that they have not made the clutch feel heavier at all. It feels very positive and I can sit at traffic lights with the clutch pulled in without problem and I am what one might describe physically as a weakling. ;D
Also, I have a non-standard clutch cable, about a third longer than usual and it is routed not following any recommendation, just where it seemed sensible to go, which is between the headlamp bracket and the headlamp, then alongside the top rail of the frame on the left side. Between the clocks felt to restrictive. Again, no adverse heaviness is discernible.
I am at a loss to advise what is happening on your bike but can say that I don't think the springs will be an issue, in my experience.
Is the gearbox clutch side cover off and so are you able to see what is happening in the basket when you pull the cable in. Is the actuator at about 4 o'clock when it engages. I have seen it happen that the actuating arm is too vertical, say 1 o'clock, meaning it does not have enough useful travel.
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Sorry Florence, nothing personal, the ones i meant were the ones who go to a parts bin and fit something from another bike.
The design of the clutch operating mechanism does tend to let the clutch slip on takeoff and power changes, my first one did for many thousands of miles and when i took it apart measuring everything all was still in book spec, i have a parts book with hand written notes( from the us ) that says use a different number plate and spring, i think from 450 twin
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Thanks Bryan, yes, I saw that online about 450 plates. Nowadays the EBC kit works well. I have been trying very hard to make it slip ;D and so far slip is gone, although first gear is quite tall and a bit of slip is required to get moving on a hill for instance.
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500 SB9 8/11/76 (USf ormat) was issued to supposedly reduce friction and wear by changing the material of the adjuster. (the bit with the slot). This seems to be after all the 500s had been produced but presumably as a result of complaints. The design is a carry over from smaller capacity Hondas of the mid 60s and made it's way up via the 450.
It can be smooth but I would not describe it as light. The 550s are light.
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Thank you all again for your responces :-) As it seems that some parts are suspisious (cable), and others worn (aduster) I have bitten the bullet and now ordered new springs, the clutch adjuster kit, need to order a new cable just to rule this out as well (recomendations please for cable). I will replace each piece one at a time and test, so hopefully I can help others with a solution should I have one that does not require all parts.
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On my 500 K1 that had standard UK aftermarket bars I bought a new clutch cable of the right length from Wemoto £12 in 2023.
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Thanks Ted, now ordered :-)
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Hi all, firstly thank you all for your help and support off the now fixed issue :-)
firstly, I replaced the adjuster purchased from CMS, mine was well worn but did not make any difference, so for future reference to others, maybe check some less costly things first. this didd seem the most logical item to replace for me.
Second, changed the cable (she came with a new cable, so the PO probably thought this was the problem?), brought new one closer to original spec although is slightly shorter than the original, this agin did not make any noticable change.
Lastly took to the clutch springs, in my haste to get thing under way, I ordered some EBC ones but did not realise until they arrived that they were heavy duty springs (15%).... When checking against the ones on the bike, the EBC were thinner?? replaced them, torqued to spec and ....... the clutch works great :-) No idea what springs were put on the bike but if anyone wants them the use as an excersize machine, I will happly post to you FOC :-)
first pic new EBC spring on the bottom,
Thank you all again for your help and support.
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Excellent news and glad HD EBC feel good, it's what I have and I am super happy with my clutch.
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You never know for certain what has been fitted in the past!!!
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Good to know you have got the problem sorted👍 and great that you have posted the solution which is bound to help someone else down the line, plus you have some extra new parts for the bike. Oh and some unidentified extra heavy duty clutch springs😂 bound to be someone with a tractor that wants them.
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bound to be someone with a tractor that wants them.
;D ;D ;D ;D ;D
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I had a similar thing with my old Triumph....I backed off the screws holding the springs and it went from needing Charles Atlas to change gear to be lovely and light.