classic motorcycle forum
Motorcycle Discussions => British Bikes => Topic started by: antoni on July 28, 2013, 09:17:20 PM
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A first post following my mate's advice that any knowledge can be had by asking on forums - AND after finding them a lot of fun.
Anybody know why my recently acquired '58 Twenty One's clutch basket wobbles and clouts the primary chain case cover?
It's my second British classic after the end of a long run of Japanese bikes. Maybe it wasn't wise to buy a non-runner even if it was 'all there'. The gearbox problem - the main problem - was just the selector forks being in the wrong way round, but other problems had crept in during the previous re-build.
To the point!
Its using a 4 spring clutch, has 1/4" dia 1/4" wide rollers and doesn't have a 'thrust washer'. The basket is a new one, the old well worn basket is in with the spares bag. Anybody know what it should have in there?
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yours has no primmary chain tentioner fitted ? sounds like wronge tapper on the hub centre
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It does have a primary chain tensioner, but it shouldn't have!
The first Twenty-one models had no tensioner and a straight-up primary chain case oil drain plug (so I was told last week by a bod wot had one). The later models had the tensioner and a slanting drain plug so that you could put a screwdriver through the hole to adjust it. Mine has the straight up drain plug, I'm wondering whether to leave the tensioner in or not bother with it - as was the original design.
The taper on the gearbox mainshaft accepts the 'clutch back flange' happily enough. It's just that the rollers and the basket don't end up happy and solid as does a very similar arrangement in my Matchless G3LS...
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it should have a thrust washer , have you changed the primmary cover in order to fit a tentionar ? triumph did not do this in 58 but said there chains where "pre stretched" latter they changed there minds , this is a 58 engine but with alloy barrels , when the clutch is fully assembled , springs etc are you saying it rocks on the main shaft ?
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Just checked the Swansea Log book, I was being lazy it's a November 57.
It came with a tensioner but I think it shouldn't have one because it's early, and because it has a primary cover without the slant access to adjust it. It does have the distributor as in your picture. Not been able to find much on the net showing them.
Just been out into the shed, it looks like an iron barrel, certainly different from the clearly alloy head. Sorry for the lack of certainty here.
I have a Haynes manual and a downloaded parts manual 'catalogue 4' both showing a 3 spring clutch with 'thrust washer'. But my downloaded Meriden 'Workshop manual' shows a 4-spring clutch which doesn't have that thrust washer. A 4 spring clutch is fitted, and the previous owner said he fitted a new clutch basket for it. The bike has not driven since.
It rocks on the rollers as far as I can tell. The mainshaft taper fits the 'clutch flange' ( my term) fine.
Should the rollers be quarter by quarter, or quarter by 6mm, and does it matter?
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so when the clutch is fully assembled you can hold the outter basket and it rocks ? what is the engine number please
First 3TA with primary chain tensioner was fitted during 1959 for the 1960 models , first engine number H18392
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Yes, fully assembled, seems to be working OK on the handlebar lever, and it rocks.
Engine and frame number H1340.
Looking forward to your comments on that. I'm grateful for your attention.
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its interesting but with the springs in ive never had this , they do rock when the leaver is pulled in or clutch disengaged to reduce this fit the thrust
can you take a pic your bike is a early one
1958
Engine Frame Numbers H761-H5480
mine is H5465
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Hi
Rollers should be 1/4 x 15/64 (6mm)
Yes vital to have correct ones
HTH
John
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quarter diamiter by 6mm long , they always looked shorter to me , but i cannot remember the last time i bought any
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Those rollers are not 6mm, a 1/4 or even 15/64 but 0.2345" which is roughly 15 thou under a 1/4". You need the correct Triumph spares rather than industrial 1/4 X 1/4 rollers as those will lock the clutch assembly. ("1/4 by 6mm"...... ::) ::))
There's no thrust washer (or ally barrels!) on the earlier C range bikes, so either there's wear on the hub or the basket is a Taiwan Ebay pattern part and probably machined to a less accurate finished size than the old one just taken off.
The tensioner being there or not is irrelevant to the clutch "rocking". Does the clutch grip when you've assembled it?
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6mm is about 0.236" and 15/64 is 0.234375", both very close to the figure given by Rex. I know nothing about this clutch but assume that there was some end float in the original so that the odd thou and a bit wouldn't be enough to bind anything. Unless 1/4" (0.250") long rollers have been used and one or more washers have been left out?
Very hard to help Antoni without having a look - correctly set up there should be essentially no wobble. The answer is to measure everything (bearing inner and outer and the rollers with vernier and micrometer) and inspect the bearing tracks under a bright light. The diameter of the inner track + diameter of rollers should be only 0.001" or so less than the inside diameter of the outer track (in the basket). Something's badly amiss if it can wobble enough to hit the primary case!
Leon
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Thanks all.
The tensioner is indeed not relevant but someone asked about it - perhaps to 'place' the exact model.
From what I've seen it is a very early model.
The clutch does grip when assembled though did slip slightly when tightening the crankshaft rotor nut.
The basket might well be a Taiwan special. The rollers seem to fit quite exactly into their space. It's quite clear now that I need new rollers, but I'd have thought the incorrect wider rollers would have reduced the rock.
The question is what else is needed. The 4-spring drawing shows doesn't showa thrust washer - and it has a 4-spring - and the three spring drawing does. I wonder if there's a mixture of the two on the bike
I know there's a limit as to how much help I can get by remote control and I'm probably about there now but thanks a lot for the advice.
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Without looking anything up I would think that talking millimetres for any dimensions except Bore x Stroke for a British bike this age is ridiculous. As far as I am aware all dimensions on British engineered machines were Imperial except that for some reason bore, stroke and capacity always seemed to be traditionally Metric worldwide except for the USA.
Certainly mixing 1/4 inches and 6 millimetre on the same item sounds rather strange.
I have a 1959 5TA which has no primary chain tensioner either. Because I have never been able to obtain a primary chain cover gasket to fit (which is different too) I have always had to make my own.
It has a three spring clutch which seems to be quite normal, though four spring clutches were also fitted on some.
By the way, that is the bike in my Avatar pretending (minus the bath-tub and plus a few 5T bits), to be a 5T!
Jim.
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I think 6mm is a few tho under a quarter , but as its on the length I doubt this is the problem , it moves that much to hit the primary something is wronge , maybe main shaft nut (kick started side) lose or bearing failed , difficult to tell with out seeing first hand , but it wont be much as these early 350 where very good and under stressed
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my 21 rollers do not fit perfectly and there is a gap left if they are all pushed tight together , there is some play in the basket but not enough to hit the casings . mine is a 58 motor . ill try put a pic up shortly .
the chain adjuster was retro fitted by owners so its no way to judge the motors age. mine is a distributor type engine .
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There's a problem here then, as Triumph only fitted 20 rollers....
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There's a problem here then, as Triumph only fitted 20 rollers....
lol
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hate to agree with rex :D but same here
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the pic , you might be able to see the primary chain adjuster at the bottom , theres possibly a roller missing in this pic as well but i do remember they did not fully fill the space .
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very nice and a very good engine , if the rollers are tight they over crowed ? not what you want , you might want to change the ht caps they look metal , and the jap ones can track in the wet
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guys.. I might be "Stating the bleeding obvious" but I think when Dunboyne said "my 21 rollers", I think he meant his Triumph 21 rollers rather than the quantity of the said item....
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that would make more sence , not just my spelling now my readings sh*T
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If Dunboyne has the original 3TA primary chaincase (which I think he said he did) the problem could be that that clutch basket looks to be the later deeper one, while the earlier 350s had a 4 (?) plate shallower basket, so the rubbing could be clearance issues rather than the actual basket rocking.
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i think he must have the latter case as its fitted with the primmary tentioner , which on my 500 runs thro the primmary , i see the frame is also the latter type
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6mm is about 0.236" and 15/64 is 0.234375", both very close to the figure given by Rex. I know nothing about this clutch but assume that there was some end float in the original so that the odd thou and a bit wouldn't be enough to bind anything. Unless 1/4" (0.250") long rollers have been used and one or more washers have been left out?
Very hard to help Antoni without having a look - correctly set up there should be essentially no wobble. The answer is to measure everything (bearing inner and outer and the rollers with vernier and micrometer) and inspect the bearing tracks under a bright light. The diameter of the inner track + diameter of rollers should be only 0.001" or so less than the inside diameter of the outer track (in the basket). Something's badly amiss if it can wobble enough to hit the primary case!
Leon
Just had a good look over the rocking clutch problem with calipers and mic.
The previous owner replaced the basket during a (failed) gearbox repair and has admitted to being unhappy with the way the clutch went together. He thought it would 'sort itself out'.
I dismantled the clutch to get the gearbox out, not expecting to see any problems with the clutch, but did notice probably recent wear marks on the case cover. So before refitting everything the first time I placed the basket on my Goldring record deck, set 16 RPM and offered a bench grinder's wheel to the edge of the basket. Turning on the cheap. Re-assembled, the clutch functioned but rocked.
Getting the old basket out of the spares pile it looks like by chance I ground it back spot-on. Original 1.635", replacement 1.636".
The rollers' bearing surface on both baskets has a diameter of 1.873". The width of that bearing surface is different; 236th original, 239th replacement. The difference might be put down to wear on the original.
I can see now the reason for the rocking. Looking at the photo, the inner roller bearing surface's width on the 'mainshaft flange' controls the position of the driven bearing hub (pictured resting on the the mainshhaft flange). The hub looks clean and sensible. When the hub is placed over the splines it rests with 269th space left for the rollers and clutch basket flange. So regardless of quarter inch wide rollers or approx 6m ones, the clutch basket is free to float by 269th minus 239th = 30th. So it rocks.
Has the surface on which the roller sits in the picture worn badly? The flange thickness is 176th, very clean and flat but has 'Spirograph' wear marks.
Advice needed!
In the absence of said advice I will try to turn back the width of mainshaft clutch flange roller bearing surface on my small lathe, so that most of the 30th is taken up, and buy new correct rollers. I expect the material will be hard carbon steel but will sacrifice a turning tool or two to get the bike runing.
...runs under the nearest table and dons tin hat...
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it will not/should not rock when the cluch is assembled and springs loaded , have you tryed this yet ? the measurements you quote as small and im surprised its enough to hit the case , does the chain line up ie is it the correct main shaft
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It does rock badly when fully assembled and working.
It rocks because there's a 30th difference between the space available for the clutch basket's flange, and the space it takes up.
30 thou becomes a lot more when you consider where that 30 thou play is, toward the middle of the assembly, and where you see the rocking/clouting which is at the outside diameter of the assembly.
Question for me is what to do about it.
Turn back the mainshaft clutch flange bearing surface to let the hub take up the slack?
Or do something less drastic which someone might tell me about!
Never used the word 'flange' so much in my life. John Lennon was fond of it I believe.
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The bottom flange of that centre looks different to the usual Triumph part, so maybe that's an after-market piece with the incorrect taper and/or too thick a bottom flange and allowing the centre to sit too far onto the mainshaft?
If it sits too far on (as also happens if you try and fit a 650 part here) the taper doesn't grab before the flange hits the alloy casing, and although the uninitiated carry on and whang on the clutch nut hoping it will all be secure and work OK, it doesn't.
Maybe the bloke who originally built it (and hoped the clutch would just sort itself out) didn't understand that centre was located by the shaft's taper? A loose taper would lead to rock too.
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The flange part is a perfect fit to the mainshaft taper. It correctly aligns the clutch basket sprocket with the engine sprocket.
There are a few different types of clutch - 3 and 4 spring, with and without a 'roller washer'. It may be that I have an incompatible set of clutch parts - or maybe not. It seems an easy fix would be to machine off some of the width of the inner roller bearing surface of the mainshaft taper.
In the real world this bodge might be easier than trying to understand and get the right parts. After all, the clutch could still be replaced in the future.
Another thing to think about is what sliding/rolling surfaces resist the clutch springs when the clutch is disengaged. As far as I can see it's the clutch basket flange pushing against the central hub through the rollers, but 'width-wise'. Don't see any wear marks at all on that part of the hub - so I must have that wrong....
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"Another thing to think about is what sliding/rolling surfaces resist the clutch springs when the clutch is disengaged. As far as I can see it's the clutch basket flange pushing against the central hub through the rollers"................ can you explain this in more detail please im not sure what your trying to say
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"Another thing to think about is what sliding/rolling surfaces resist the clutch springs when the clutch is disengaged. As far as I can see it's the clutch basket flange pushing against the central hub through the rollers"................ can you explain this in more detail please im not sure what your trying to say
It's a bit difficult to get your head around but just had another go.
When the clutch is engaged it just sits on the mainshaft and transmits torque to it, with or without wobble. All parts of the clutch are rotating at the same speed, which is the same as saying no parts are rotating with respect to each other. So there's no worry about anything wearing against anything else.
When disengaged, the clutch parts are not only rotating at different speeds, but the push-rod is pushing the clutch assembly 'outboard' of the bike, creating a side force.
Of course the side force is your left hand against the clutch springs. Consider what the path of that force is.
The pushrod pushes the clutch pressure plate outboard and compresses the springs (from the inside). The springs respond by pushing on the slotted spring adjuster nuts, which pull their bolts. The bolts pull on the clutch hub. What restrains the clutch hub? It's the tight main nut pulling the hub against the clutch flange, and in so doing holding thee clutch flange firmly onto the mainshaft.
So the basket doesn't take part in procedings. It doesn't have to handle any side force against its guides, only rotating radial force, handled by the rolllers.
Thanks to Wetdog for forcing me to think about it more carefully. I only worked out there's no problem with side force writing this! And there are the spiral wear marks on the inside of the hub - I was at work and couldn't look at it when I wrote the last post.
Rock's still there tho...
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Hi Antoni
The picture shows the roller bearing almost to the end of the bearing surface, this is correct
The "hub" which fits over the splines should fit against the roller race shoulder
It sounds to me as if the "thick washer" that fits in before the nut is missing, this washer is about 5mm thick and holds the hub against the shoulder and the nut locks everything solid
In your case it seems the nut is holding the shaft adaptor and not the hub
If the inside spider of the hub shock absorber is worn where it fits against the roller race it can lead to the clutch locking up when the nut is tightened >:(
HTH
John
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Hi Antoni
The picture shows the roller bearing almost to the end of the bearing surface, this is correct
The "hub" which fits over the splines should fit against the roller race shoulder
It sounds to me as if the "thick washer" that fits in before the nut is missing
...snip....
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John, thanks for the input.
Anyone, thanks for input.
That cup-washer (think that's what the books call it) is present. So the nut does act through it onto the splines of the mainshaft flange, the hub being trapped in the 'spline-space' hope you can see what I mean.
The inboard surface of the shock-absorbing hub is indeed acting against the shoulders of the rollers. Unfortunately, for whatever reason, there's 30th end float for the rollers, and significantly the clutch basket flange, to rattle around in.
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interesting , ive just measured my 1958 clutch basket , from the out side edge of the teeth to the edge of the basket its 22 and 1/2 mm ...... but looking at the primary cover (no tentioner type ) it looks a bit shallower over the clutch compared to my later t100 primary cover , but you have the latter primary so don't think its a case of shallow type primary , also the basket would not wobble unless it hits something when spinning (in this case the outter cover ) , all said I would try a roller thrust shim ............... mine is also a 4 spring type and I have fitted roller thrust shim (twice as it did ware one out ? )
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one other thing , you say the chain lines up , but the crank nut looks to be a way out off the end of the crank , has some one spaced the crank sprocket out ?
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Hello Wetdog,
The dimension you gave, not sure what it refers to. Do you mean that if you laid the basket flat on a table it would be 22.5mm high?
Anyone know how thick the shim is? 28th by any chance?
BTW, I haven't shown a picture of my crank - the pic in post 19 is someone else's bike. The sprockets line up and the chain run path looks sensible. I have the earliest primary chain case cover with the vertical oil drain. It fits the unit-engine properly. Someone has retrofitted a chain tensioner, I'm minded to leave it out as it has a new chain and has none of the droop visible in the earlier picture (yet).
Just spoke to 'Tri-Supply', he said there should be no shim at the rollers on a four spring clutch, and that all bikes were fitted with 4 spring up to the 60s. He's sending me some ~6mm by quarter rollers, but had been thinking he was selling quarter by quarter until he measured them. He didn't offer any opinion on why the clutch rocks. He said there should be a bit of rock. Did he say 1/8th? Mine's more like 3/8ths - 1/2 inch.
I'm getting closer to attacking things with a lathe....
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"Someone has retrofitted a chain tensioner" .... how ? the later chain tentioner needs the latter primary so how is it you still have the early cover ? the 22half is with the basket fitted measure with a rule butted up against the teeth on the basket to the edge of the same . the early cover with no tentioner looks shallower to me , but cannot be 100% as the t100 one is still fitted to the bike , im wondering if they made the clutch basket wider for some reson , can you post a pic of your retro fitted tentioner thanks ( ps they did make alloy barrels for 3ta )
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"He's sending me some ~6mm by quarter rollers" ................. just read this again , if you have 1/4 .1/4 rollers now and fit 1/4 ,6mm wont this make it worse ?
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"He's sending me some ~6mm by quarter rollers" ................. just read this again , if you have 1/4 .1/4 rollers now and fit 1/4 ,6mm wont this make it worse ?
Yes. My quarter-wide rollers are currently improving the symptom very slightly, but I want to fix the problem.
I'll photograph the tensioner set-up as it was at disassembly. It's clearly wrong because the adjuster screw fouls on the bottom of the primary case.
I'll compare that dimension you gave with mine when I go back into the shed.
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I really need to pay more attention this early alloy barrelled 3ta I have here (vertical drain etc) has a chain tentioner fitted , but can only be accessed when the outer shallow cover is removed ( how I missed this I don't know) unlike the t100 which can be accessed via the oil drain so no need to take primary off , does yours look like this im not sure if this is a retro fit or original , the clutch does not rock
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Yes. My quarter-wide rollers are currently improving the symptom very slightly, but I want to fix the problem.
All those roller are 1/4" wide (diameter) but genuine Triumph ones are 17 thou shorter in length. Anyone actually asking for 1/4 X 6mm rollers should raise a hearty laugh at the suppliers anyway... ;)
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Interesting size naming convention you're using there Rex!
The supplier did not know that the rollers he has been selling were quarter by approx 6mm. Only after I asked him to measure them did he realise what he had - with some embarrassment I think.
I don't see anything wrong with mixing metric and non-metric if it's convenient and clear.
The works warehouse floor is marked with metres and cubits.
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I'm not using it, but quoting it from the previous posts.
It's just daft to mix units like this. It's like the DiYer who asks the timber merchant for 2 metres of 4X2, or the nut and bolt stockist for M6 by 2" set screws usually to much hilarity from the staff... ie it's laughable in any mathematical or engineering context.
More seriously Triumph didn't make 1/4 X 6mm rollers, they made 0.250 x 0.234 rollers. Nothing to do with 6mm, ever.
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4 by 2 is sold by the meter , bad example , but I do know what you mean
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author=antoni link=topic=4694.msg18592#msg18592 date=1376488990]
I don't see anything wrong with mixing metric and non-metric if it's convenient and clear.
Been giving that one some thought, and I can't envisage any situation where mixing units would be more "convenient" than just following normal convention and sticking to one type or the other. :-\
The works warehouse floor is marked with metres and cubits.
Any particular reason why that warehouse is using units which mean absolutely nothing to 99.9% of the general population? ???
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If I need a bearing or bush there is a small local shop,used to be a bearing outlet, but has been taken over and turned into a r/c toy car shop.If I go to get something like a sintered bronze bush(they have large stocks),and mention 5/8 or 13/16,the ten year old at the counter says Im doing his head in.The fourteen year old manager comes out with his laptop,or tablet or smartphone or something,and says everything is converted to metric,with dimensions to six places,and that is the only way to identify anything in stock.Thats progress? Regards John.
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But surely any old stock of Imperial bushes will still be marked with those old Imperial sizes, so why would they need to convert in this way?
Better to go to someone like Bearing Boys, at least they recognise that there won't be direct and suitable metric equivalents for all (if any) Imperial sizes and so stock both ranges.
http://www.bearingboys.co.uk/Oilite__Bearing_Bushes_-1011-c
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All the bushes are marked with the manufacturers part nos ,which are common,like ball bearing no s.However the young persons running this place have chosen to allocate their own system,and store all stock accordingly.The shop is about 1/2 mile away,a nice run on my Ariel,other bearing outlets at least a twenty mile round trip.Probably too much for the Ariel.Bearing Boys would be a 20,000mile round trip,definitely too much for an Ariel.Regards John.
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which Ariel have you ?
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4X2 is sold by the metre but I always have 8 inches left over.
What can I do with 8 inches?
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.... so you.ve got wood?
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Three things make me think all's OK now.
A surprising amount of clutch rock is normal, I've been educated on that point.
I ground off a tenth of an inch from the depth of the clutch basket to help stop case clouting.
The rocking of the clutch had been increased by the rocking of the inner driven hub on the splines of the clutch flange (which sits on the main shaft taper).
To cut to the chase, rightly or wrongly, ground/machined 4 to 5 thou off the outboard end of the clutch flange. This took up most of the rocking of the 'driven hub'. I noticed that the pressed steel 'cup washer' under the main clutch nut was dished convex on the inboard side. I made it almost flat That produced a solid inner driven hub wrt the mainshaft. That didn't seem right either. A ~4th step was machined back onto the inboard of cup washer to allow it to tighten hard onto the 'clutch flange' but not hard onto the end of the splines of the 'driven clutch hub'. The final result is very slight rock of the inner hub and slight rotational play restrained by the spline arrangement.
The clutch was re-assembled and now the rock is significantly less, much more like the amount of rock I remember when putting my Matchless G3LS together.
Now just the usual crap electrics which shorted out and needed hot-wiring to get me back home on my first ever ride on the bike and the ubiquitous primary case oil leak to sort out. Thought it was a nice ride tho.
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the crank nut still looks a long way out , the washer you talk about is stepped as standard , there should be no play on the hub centre splines , I see you have converted to 12v a good idea but not sure about spade conections inside the primary . they are a very nice engine and one of the smoothest triumph I have ever had .
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Good that you've got it cracked. I've never worried too much about modifying components in this way, after all, it's better to be riding it than obsessing over not having the correct 1962 squiggle washer. Mixing and matching 50+ year old parts can be fraught at the best of times anyway, and that's with a mass-produced bike too.
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Rex, thank you for my absolution.
The warehouse floor is marked with cubits for a laugh. A foot is such an intuitive measure of length. An inch being a finger knuckle is too. Granted a cubit - about a fore-arm's length - is a bit less useful. Remember that the Ark was built in cubits by an amateur and the Titanic was built in imperial by professionals.
I didn't convert it to 12V and I wish it had not been done. There's nothing wrong with 6 volt electrics if they are designed, built and maintained properly. A 35 watt bulb is 35 watts whether in a 12 volt or 6 volt system. What matters is that the bulbs get all of their volts and that none of them are stolen by high resistance thin wiring and crappy crimp connections (robbers of a lot of millivolts IME). My 6 volt Matchless was fine coming home last night.
Re the crimp spade connectors, yes dodgy. Worried about oil and temperature resistance of the 'mains wiring' too. But there's so much that's not quite right or just plain wrong about this bike. I just want to get it driveable so my long suffering Matchless can be stood-down for long overdue maintenance and repair. I've got a very nice car but it sits on the drive over the weekend now I've discovered wonderful old bikes.
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I didn't convert it to 12V and I wish it had not been done........................ the alt looks like its setup for 12v , I conterted mine to 12v no problems and lights are quite good , are you having problems
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".... the alt looks like its setup for 12v"
Yes, it was set up for 12 volt by a previous owner. Trouble is, the whole electrics are poor. Look at the pic showing the mounting of the zener. Believe me that's typical of the general electrical workmanship. I'm going to leave it like that for a while and hope for a few smiles.
But I need to sort out the wiring so that it doesn't short when everything which should be grounded is grounded. That's what happens at the moment.
No point explaining this in detail on here but when I got the bike the electrics seemed to rely on a poor electrical contact between the headlamp bowl and its rusty mounts. During the clutch/gearbox test run the vibration wore the rust through and the short stopped the engine. ........but only fried the fitted 30 amp battery fuse - didn't part it.
Stop typing stop drinking go into the shed and sort it.