Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: McCabe-Thiele (Ted) on May 05, 2024, 08:20:32 PM
-
I had a second wind this evening so with the rear wheel in position, no brake shoes binding, attached the brake anchor bar to the hub.
With the axle nut loose the wheel rotates freely, as I tighten up the axle nut the wheel is stiffer to turn so something must be amiss.
It will rotate by hand but with much more effort.
The axle shaft fits easily through the hubs etc no force needed.
The fixed bearing was fitted without issue with the small spacer and the long spacer in position
Right hand bearing knocked in easily.
Left & right spacers in the correct position.
I haven't as yet fully torqued the axle nut wtf is going on?
Is it possible that the right hand bearing is not full against the central long spacer so it might improve the situation at full tightness?
I can't seem to find a picture in the parts book for the fitting of the rear brake hub anchor parts or what way round the shouldered bolt should fit - is it with the split pin on the inside or facing out?
-
I can only think that it's tying up on the bearing Ted, maybe you need to drift it in ever so slightly more?
-
Could be Dom, ill remove the brake hub and give it another thwack with the drift.
Update: The right hand bearing was not flush with the hub face - it did not want to knock in any further so I undid the lock ring on the left side and it's now flush with the face.
Now the lock ring is not fully against the drive hub so I guess I might need to tap the left side bearing a tad more from the left side.
Not sure if there should be a gap between the lock ring and the drive hub. Mine is probably about the thickness of a Junior hack saw blade between the lock ring and drive hub face .
-
Unsure if I've understood correctly the current adjustment just made Ted.
The left bearing, with retaining ring has only one true position which is "fully" located in it's accompanying architecture.
This is the wheel datum (same on front too) for the rim alignment in the chassis, with all other spacing etc slaved off this installation. Bearing race fully home and retaining ring fully tightened is the only method, anything else with compromise doesn't take precedent over this procedure. The other parts and alignment should be looked through for fault if it exists then.
If the primary, LEFT bearing isn't secure in it's location, then the wheel can move across the axle during use :o to the detriment of competent running and risk of jamming the wheel in cases of significant movement.
-
Good point I'm going to get the fixed bearing fully home as it was before. I'm thinking the right side will move back out a little but not as far out as it was.
I understand the fixed bearing principle - the lock ring seems to have two functions. Securing the fixed bearing and holding the drive hub fully home.
Update:- I removed the lock ring (again) and using a drift with a good sized lump hammer the left side bearing is fully home. The hammer strike changed tone as it butted up to the recess. Drive hub and lock ring fitted back and it's fully tightened with no gap visible between the ring & hub face. Visually the right side bearing has moved out slightly but nothing like it was.
I now have a slightly different issue that existed before I stripped down the bike - some light binding. The rear brake linings have a very slight bind. I had to file the brake shoe ends where they pivot as there was no room for the top washer only the split pin. The brake shoes also appear to be a tad wider than what feels right when you fit the brake hub it's a difficult wiggle.
There is no free play in the brake shoe system. A very slight amount of lever movement in either direction applys the brakes. It's diffucult to pin down but it feels as if the binding is more like the side of the brake linings touching the inside of the hub.
From previous posts it appears that the original brake linings are no longer available so it's a bit of a raffle to get the correct ones. My next move is to see if a chamfer on the inside edge of the curved shoe might improve things. I think but am not sure that the hub has had a new steel lining fitted in the past.
I'm going to remove the brake shoes and re-fit the hub to be 100% sure it's just the linings causing the bind.
-
Ted i think that was one of 3 i had relined by Paul in Huddersfield when he was doing them.
As far as i know he used cast iron pipe not brake drums and did do them to smallest size.
It was a long time ago so maybe a bit of corrosion, i would use a flap wheel in a drill to clean out the drum.
-
Thanks Bryan - a few minutes ago I took out the brake hub- removed the shoes - put it back into the wheel - torqued it up rotated freely - so it's just a very close fit - as it was when I first rode the bike.
The Shoes look like the DS ones they are marked SOK 283 .
Bryan I have never had a flap wheel so how are they sized can you post or PM me a link as to the size & grade I need please?
I assume they will fit a normal drill.
-
Go to ebay and search flap wheel, i would use a 2 inch 60 grit to clean the drum, having seen them you may get them localy to you, b&q do them
-
Thanks Bryan.
-
Screwfix certainly do flap wheels
-
The brake binding is not present until I tighten the axle as I increase the tightness the binding starts.
To make sure it was not the bearings I removed the linings re-fitted the brake hub - all free.
The only thing that really changes when it is tightened up is the inside edges of the brake shoes are closer to the inside of the wheel. There is no sign of any lip on the liner.
Where the liner meets the wheel internals it looks visually good with no sign of any lip. It might be worth doing some very slight sanding on the inside edge of the brake shoes or even a light shamfer on the outer circumference/edge of the lining.
I did wonder if I could mark the outer edges with some yellow road chalk and see where it transfers to.
-
If it is ok with no shoes fitted and done up tight it cant be bearings or brakeplate.
It is possible that the shoes are too wide, you could put a smear of coloured grease( coppaslip comes to mind) on the edges of the shoes and see if it transfers to hub or brakeplate, i have also had shoes where they dont sit properly on the cam as they are fractionally too wide, you said you had to thin the hole end so leave springs off and see if the flat pads sit asquare on the cam.
We are at the mercy of the manufacturers and suppliers of pattern parts who dont seem to take as much care in manufacture.
When available i always use Vesrah, they seem to be a better maker
-
I have filed down the shoes to enable a washer to be fitted under the split pin.
On closer examination of the brake shoes alloy plate there were a couple of what looked like rub marks on the alloy shoes on the outer edges. This was just on the one shoe. I have done some very light filing of the edge it has reduced the binding substantially when the axel is tightened up.
I am collecting a flap wheel today as well - Bryan -who sells Vesrah brake shoes in the UK?
-
Last ones i bought was 7 years ago Ted so cant help much
-
I was quite pleased with my Flap Wheel that I bought from Scewfix - trouble is it will not fit in the gap between the hub brake lining and the center of the hub - I'm sure it will come in handy in the future!
Undetered I decided to use a pair of those dark green plastic wheels that Ken uses for polishing work. A steady five minutes with them in my Dremell, the brake liner cleaned up really nicely. Hub fitted back in the wheel, nipped up, a couple of high point rub marks on the brake lining near the middle towards the edge of one brake shoe. Hub removed some sand paper on the high points, Repeated twice - all is now as it should be - wheel rotates freely at last!
I've lost count of how many times the back wheel has been removed and re-fitted over the last two days - it was worth perservering to get it right.
Thanks for the tips from those who replied to this post.
Thank goodness for my bike ramp it made it all so much easier - time for a Beer reward!
-
Good work Ted.
Its a skill that used to be genuinely labelled "Mechanical Fitter" in which the person assembling etc had to be adaptive with approach to competently build assembled machinery.
What could be "fettled" aspect of structural, mechanical and metallurgy, all part of training to cope with various components from disparate scource being built into one machine.
Quite a valued occupation, when we used to make things in this country :)
-
Ted, you have just completed something a younger mechanic would fail at mate.
By the way the chain whilst new was not an expensive one
-
Ted, you have just completed something a younger mechanic would fail at mate.
By the way the chain whilst new was not an expensive one
It's marked DID on the links so I'm happy with it to go back on - it's not going to see much mileage in my ownership.
My target date was to have it running for my birthday - I've missed that by two days already. As I have my 400 to use I'm in no hurry to get it finished this month - it's still not very warm in my garage either.
-
It's 23C "up the smoke" in the great metropolis today.
Sweltering darn sarf ;D
-
Good fettling Ted. Sounds like you’re getting close just as the weather is picking up👍
I’ve previously been confused by the interaction of the spindle clamping and bearing fitment on other bikes. . Inner races spin easily after bearing fitment but then are pressed against the spacer tube by tightening the spindle. I’ve changed bearings thinking they were tight only to find they were fine once removed. Am I missing something?
-
In concept, the inner race of the bearings form one complete tube along with the other bits mounted onto the axle, tightening should clamp all those elements tight together in one continuous load path.
In production reality and tolerancing, the bearing "seats" in the wheel casting and the bearing spacer length would have to be very accurate OR individually shimmed to get an exact match once torque is applied at assembly.
What the common design does is to to use one reference bearing (usually the chain side on rear, often left side on front) to fully fix the outer race hard against it's hub shoulder, then retainer ring to keep it from moving.
The opposite side is usually left with some space between outer track and wheel shoulder, this to effectively "float" in the wheel axialy. That can then be used for tolerance of the assembly comprising of primary bearing, spacers etc. Not too critical in other words, the primary bearing controlling lateral location.
It SHOULD turn freely when all tightened, but will accommodate some bearing preload if need be (that would mean spacer total was less than the two hub shoulder in dimensions) with any significant drag being cause for concern and a look at just what components and their placing is doing in there.
If the rear wheel was tightened with no brake drag and no chain fitted, then likely you'd feel some small shift in rotation with anything significant causing more concern. They should spin reasonably easily, but not like a bicycle wheel does :)
It's odd to describe and sounds like a "fudge" to say so, but unlike setting a bearing arrangement for preloaded by measuring turning torque etc, these are just meant to be assembled, correctly, with no real methods except assuring the right parts are used and in the right place.
Judgement would give that any significant changes as it's tightened should raise questions, as Ted's done, then investigating exactly how the various parts are installed to try and make absolutely sure all is in the right orientation.
Bit long winded, but difficult to describe in a different way,, possibly :)
-
Only thing to add to that is that in design they take into effect that a ball bearing hates sideways load and will fail quickly if this is applied unless specificaly designed for this with different, expensive, races
-
It's different but the same in some aspects as the old Mini Cooper S had taper roller bearings in the front hubs that were not adjustable you just torqued them up. The other Minis all had plain ball bearings.
-
Good work there Ted! Had to do similar work on my replacement shoes on the 550 except they weren’t binding when fitted.👍
-
I have this task coming up in a month or two. There I was thinking I just screw everything back together and job’s a goodun! Another learning opportunity looms. I suspect I will be re-reading this thread carefully. Thanks for starting it Ted.
-
I had no issues Mike when I did my 400 rear wheel so I was well miffed when the 500 did not work out first fit.
After chatting to Ken on reflection I obviously did not fit the right side bearing fully home. The 500 has that short extra spacer that fits into the left bearing as well as the long center spacer. Make sure you fit the short spacer fully home into the fixed left side bearing before you fit it.
-
In concept, the inner race of the bearings form one complete tube along with the other bits mounted onto the axle, tightening should clamp all those elements tight together in one continuous load path.
In production reality and tolerancing, the bearing "seats" in the wheel casting and the bearing spacer length would have to be very accurate OR individually shimmed to get an exact match once torque is applied at assembly.
What the common design does is to to use one reference bearing (usually the chain side on rear, often left side on front) to fully fix the outer race hard against it's hub shoulder, then retainer ring to keep it from moving.
The opposite side is usually left with some space between outer track and wheel shoulder, this to effectively "float" in the wheel axialy. That can then be used for tolerance of the assembly comprising of primary bearing, spacers etc. Not too critical in other words, the primary bearing controlling lateral location.
It SHOULD turn freely when all tightened, but will accommodate some bearing preload if need be (that would mean spacer total was less than the two hub shoulder in dimensions) with any significant drag being cause for concern and a look at just what components and their placing is doing in there.
If the rear wheel was tightened with no brake drag and no chain fitted, then likely you'd feel some small shift in rotation with anything significant causing more concern. They should spin reasonably easily, but not like a bicycle wheel does :)
It's odd to describe and sounds like a "fudge" to say so, but unlike setting a bearing arrangement for preloaded by measuring turning torque etc, these are just meant to be assembled, correctly, with no real methods except assuring the right parts are used and in the right place.
Judgement would give that any significant changes as it's tightened should raise questions, as Ted's done, then investigating exactly how the various parts are installed to try and make absolutely sure all is in the right orientation.
Bit long winded, but difficult to describe in a different way,, possibly :)
Thanks for that helpful clarification. I remember now what the issue was on a front wheel. After shouldering the first bearing continued driving inward of the the outer race of the non shouldering second bearing using a socket jams the the inner race against the separating tube and introduces side load by pushing the outer race further inward. It’s a matter of feel to decide when to stop since there is no shouldering of the outer race. So to get a free spinning bearing I had to pull it out slightly again. When tightening the spindle with its spacers fixed length of the inner race assembly prevents excessive inward movement of the outer race.
-
It's probably between my ears rather than reality - when I did my rectification fit of the right bearing instead of using my lump hammer as previously to get it fully home - I used my Orange Plastic shot filled hammer for the final strike - thinking it might stop a rebound.