classic motorcycle forum
Motorcycle Discussions => British Bikes => Topic started by: DELONSTAINWALL on April 03, 2019, 01:10:15 AM
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Hi members,
I am about to work on an Excelsior Universal 125cc. That is for respray and bring it back to life again. Can someone advise me on how I could take out the rear plunger. There is one large spring on the top and on the bottom a smaller spring held onto the bike frame by two small bolts top and bottom. Any advise on how to take this out will be great.
Thank you, Delon
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The way these usually work is that you remove the bolt top and bottom, and knock the central shaft upwards,until the sliders and springs can come out, sideways
WARNING - they can potentially come out at lightning speed, and do some serious damage. !!
Wrapping them in a (strong) towel or blanket so they can't escape is a good idea.
As also is lashing them with ropes, so they can't escape far.
Inserting them back in is an interesting exercise also, they usually have to be compressed with a threaded rod and nuts and washers,
wangled into place and the nuts eased off so they slot into position.
WARNING If they escape they can do some real damage.
The aforementioned towels blankets and ropes are some insurance against this.
Never stand in the line of fire, as it were...
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P.S. There would have been some covers over that top spring ?
Rubber bellows type, perhaps ?
Possibly also over the lower one ?
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HI there
Really appreciate your reply.
Unfortunately, I had tried to do exactly you have described and the central shaft does not want to move upwards. (please see attach picture)
Thank you
Delon
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Mmmm, maybe Excelsior don't quite use the usual system of the central rod in these.
What happened when you tried your rubber or hide mallet to tap this upwards ?
That looks like a rather slim nut at the inside base there, could this be undone with a very slim spanner and used to pull the rod upwards ?
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I seem to remember that the Excelsior system was back to front compared to the common BSA plunger system.............in fact they used the same system as Indian,where the axle mount is connected to the outer cover,not to an internal slider..............as to removal,it certainly looks as though the whole unit with rod is slid up through the top mount,until it clears the lower mount.
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Hi Delon.
I had a similar problem with my Norton ES2. The saga is here: http://classicmotorcycleforum.com/index.php?topic=5700.0 (http://classicmotorcycleforum.com/index.php?topic=5700.0) - it may be helpful to you.
Be very careful as those springs can pack quite a punch......
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I seem to remember that the Excelsior system was back to front compared to the common BSA plunger system.............in fact they used the same system as Indian,where the axle mount is connected to the outer cover,not to an internal slider..............as to removal,it certainly looks as though the whole unit with rod is slid up through the top mount,until it clears the lower mount.
I have an Indian and the axle is connected to an internal slider. The covers are just chromed MS. The Indian plunger assy needed the threaded rod tool to compress the springs enough to start the threaded bottom cup, but my BSA A7 just needed a hefty push down to get the springs etc back into place. Hard push down, but it can be done easily enough.
On the BSA the threaded column was punched down through the slider after all the three bolts (top middle and bottom) were removed. I covered it in a piece of carpet after hearing horror stories of springs sticking into ceilings, but it was nothing like that ferocious.
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Thank you, Members,
R, When I got this, it had no rubbers on the plunger springs top or bottom. R, the only nuts on the plunger is the two large chrome nuts and the two holding the plunger top and bottom. Iansoady thank you for the pic, didn’t help.
The plunger moves up and down the shaft. The centre rod does not move and I have tried hitting it out from the top (large spring end) and from the bottom (small spring end) but it feels like I am hitting solid metal. I don’t want to damage the rod by hitting it harder than what I have. Other pic of this motel does not have springs on them just the plunger only. When I compress the large spring the centre rod does not move.
Please advise what I can do next Members.
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The outside springs are not original,been added to modify the unit....................the original setup is the centre part with springs enclosed in the unit by the two threaded end nuts,and the rod fixed in the frame................with a bodge ,its always possible the centre rod has been welded or brazed into the frame..................but first I would clean up and wire brush(sandblast better) the frame to rod mount area.,so you can see whats going on..............the rod may be threaded at the bottom,and just needs to be turned out to release the unit...........................my thought for the day.......a thoroughly bodged british bike is a formidable adversary.
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Had a think about that .........its going to very difficult to disassemble.................firstly,the rod has a boss in the middle ,inside the springbox,so it cant be driven thru.........secondly,the added springs make the unit near impossible to dissassemble in the intended way,which is for the spring unit to be pushed upward until the rod clears at the lower mount,twisted sideways enough to clear the lower frame ,and the whole unit pulled out downwards...............note that the correct springs(inside the box)play no part until you unscrew the end caps...................BUT......the very solid exra top spring makes that method very difficult...........the whole unit is going to have to be compressed upward,and hopefully ,doesnt become coilbound before the lower end clears the frame.................SO.....dont hit the rod,it cant be driven anywhere ,and will end up mushroomed..............
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Thank you, John.K and members,
I have compressed the large spring (top end) with the plunger upward but I cannot get the clearance to get the centre rod out of the lower frame. See photo attached. Please advise next step. Thank you Delon
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I think the movement inside the spring box is the problem................I would compress the springbox/plunger upward by using a bearing puller under the lower springbox nut,and two long threaded rods to the top mount.............I dont know what tools you have,but with minimal gear,i think you might have a two leg puller you could use to force the rod up enough to clear the lower mount.............as I said ,hammering is no good,as the spring just pushes back.............I have tons of OTC puller stuff for industrial use,which you could use ,except you are 3,000 miles away...................I hesitate to advise cutting the upper spring,because it may be the spring out of the box,but if that upper spring is cut away ,the whole unit will easily slide thru..........I dont know how easy parts are to find.,but dont wreck anything that cant be replaced.
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Thank you, John. K
The top (large) spring and plunger moves up about 2cm when I compress the spring. I still need for the central shaft to move up witch it doesn’t. It seems like the sleeve and the central shaft on top and bottom side is one peace. When I compress the spring, the central shaft does not move. only the plunger moves up when compressed up.
Please advise.
Delon
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All I can see needs to be done is to force the springbox assy upward as far as possible,using a bearing puller under the lower nut,then you need to force the rod upward as well......................however ,if you have a bearing puller ,you can also try closing it onto the shoulder in the rod we can see in the latest pic..........I realize this may mean you need two bearing pullers ,so as to leave one under load ,while positioning the other on the rod..................another point...does the rod have a threaded hole in the top ......it may be possible to insert a bolt and spacers to maintain position while you change pullers over................as I said ,a last resort will be cutting the spring away.
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Thank you, John. K and members
From what I can understand are you asking me to compress the plunger as per the larger arrow and then compress the central shaft as per the smaller arrow? pic attached.
regards
Delon
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Yes,there isnt any space there ,but you might be able to get a small bearing separator in under the lower dome nut........and seems you may have to push the rod from the end,but would be better if you could use the shoulder just below the spring........................As to removing the top spring.................it would depend on whether there is a spring inside the unit........remember that upper spring will actually go into the lower side of the springbox..........anyhoo,if the outside springs are extras ,cutting one isnt problematic.......but if they are from inside ,then you will be looking for replacements.
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I'm sorry you felt my post (which if you read it was rather more than a pic) was unhelpful. However, if you adopt a similar approach, ie cutting through the central rod (and probably, in your case, the springs) with an angle grinder, you will be able to dismantle it. Having done that, making a new rod will be a simple machining job, and wherever in the world you are springs are easy things to have made.
What you do need to do is to avoid destroying irreplaceable parts like the alloy casting.
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Thank you, John. K and iansoady.
I truly don’t want to start cutting anything if possible. Iansoady any help is good. I may have used the wrong words.
John K I will try doing this on the weekend and let you know how it goes.
I am waiting for the service and parts manual that I have ordered perhaps this will help me?????
Delon
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I spoke with an Excelsior enthusiast pal of mine this morning and he demonstrated the finer points (!) of plunger dismantling on an example which happens to be sitting in his kitchen. Once the nuts top and bottom have been removed the central pillar should just knock out, it's that simple. However in reality, the block on which the wheel spindle sits is bronze bushed and is likely to be seized to the column. Due to the construction method you will struggle to get enough heat and lubrication into this area so you may well have to cut the pillar. He says these were originally a surface ground bar which may be hard to find today in an Imperial size but there is a near Metric equivalent which can be used. Since you will have to rebush the block make new bushes to suit.Either way you'll need a friendly engineer to make up the parts if you can't do it yourself!
REgards, Mark
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Think he'll be lucky to have a bronze-bushed slider on an economy lightweight. Even the mighty BSA used a steel slider direct onto a steel column, but then again steel on steel would be more likely to seize together.
If this was the case, hitting the top (or bottom) of the central column should see the spring compress, but I got the impression that the OP said it was more "solid" than that.
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His whole? problem is the external springs added by a previous bodger........the Excelsior unit should remove easily from the frame,the extra springs are preventing movement ..............there is a truism with british bikes .......smaller the bike,bigger the bodge.........................although the best bodge I have seen is a large torque converter filled with concrete to restore drive in a big tractor........now thats a bodge.
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A large part of my so called 'restoration work' is just de-bodging and returning a bike to bog standard. Then it drives me nuts when people say 'It runs really well now so I think I'll just do so and so and such and such to improve it '. I then watch it all go downhill again.
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Almost an impossibility for any bike approaching 80 years old not to have some bodge or other inflicted on it somewhere, even if it's only some ba*tard tapping out a thread to take a metric stud or whatever, or taking a stick welder to the centre stand lugs.
They've spent too long at the "that'll keep it going for another month" value stage for things to be any different.
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Thank you, to all members for your input on this subject.
I have spent several hours attempting to take the plunger out as per your instruction’s members. The only thing I haven’t done is cut the centre rod which passes through the frame. I am sure if I cut this, I will be able to take the plunger out. Tapping the centre rod from the bottom does not help as I believe the rod is seized. I have just managed to get a Pic from a friend of mine Alwyn. Please see attached. The instructions state that remove nut N and tap the centre rod from the bottom. This is not happening to mine plunger. Please advise further?
Best regards Delon,
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You will have to cut away the upper spring............that is what is preventing you from removing the unit............I would use the oxy,but a 4" angle grinder with a thin cutting disc should demolish the spring without marking the frame........I would not cut the rod,as it likely has a boss in the middle......IE is not a simple rod.......so making one might be a challenge ,or costly if you dont have a lathe.
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I've come in late here, but has anyone suggested pressing the rod out? Hitting a rod or spindle does tend to expand it.
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I'm pretty sure he'll have to do the same as I did. If he uses a thin cutting disc he should be able to cut the central pillar without damaging the spring (too much).
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Thank you, to all members for your input
It looks like cutting the top spring or the central shaft is my way out of this?
Any further advise?
Delon
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toss a coin.....the spring or the rod?.............Brexit or no brexit...........decisions can all be simplified by a coin toss.
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In my experience, cutting the spring alone won't release the unit. Go for the central pillar. If you use a thin cutting disc in an angle grinder you should be able to do it with minimal damage to the spring by going in at an angle between 2 coils. However, you'll still have spring pressure so you may end up cutting the spring as well.
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Thank you, John. K and members,
Looks like my work is cut out for this project. Will let you all know how I go with Brexit or no Brexit.
Delon
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Hi Members,
Cutting the top large spring did not help I still couldn’t take it out as the vertical tube feels stuck to the centre rod. Any further advise? Should I cut the rod next?
Delon
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Isnt there a pinch bolt retaining the rod at the top mount?...isnt the bracket slotted to the hole ,so the rod can be released by opening out the slot with a chisel or tapered drift?...............IMHO,you need to free up the top mount,slide the rod upward enough to clear at the lower end,twist sideways ,and pull the rod down..............cutting the rod works for the immediate situation,but then you have one more part to find,or make..............
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Hi Members,
Cutting the top large spring did not help I still couldn’t take it out as the vertical tube feels stuck to the centre rod.
I can't visualise the design of this set up. On the ones I've worked on the "vertical tube" is the "centre rod", and the axle carrier casting slides up and down on the centre rod. Does this centre rod move in the top and bottom lugs at all?
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Hi Members,
Cutting the top large spring did not help I still couldn’t take it out as the vertical tube feels stuck to the centre rod. Any further advise? Should I cut the rod next?
Delon
That's exactly what I've been telling you.
You'll almost certainly find that the central rod is seized in the slider which is why you can't remove it in the conventional way.
BTW is it a problem on both sides or just one? On my Norton, one side came apart relatively easily so it was a simple matter to see what was going on.
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Rex is quite correct........the whole unit .rod and all should slide upwards through the top mount ,when the bottom bolt and top pinch bolt are out............you should be able to remove the whole plunger unit and rod in one piece,then when out,unscrew the end caps of the plunger unit to free the springs........................unless someone has welded the top mount and rod together...........then you must pray for a poor weld ,which can be broken after a bit of grinding............ian ,this unit is quite different to a Norton plunger,inside out ,as it were.
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I may be missing something (often the case) but:
1. There is no upper pinch bolt evident on the photos.
2. Even if it were "inside out", it's obvious the slider is seized onto the central spindle: "the vertical tube feels stuck to the centre rod"
3. I can see no way of removing it other than cutting the central spindle.
4. The only part small enough to slide through the top mounting is the spindle. So I can't see how "the whole unit .rod and all should slide upwards through the top mount ,when the bottom bolt and top pinch bolt are out."
I will of course look forward with interest to see how the saga develops. And of course am happy to own up to any errors in my recommendations. Having said that, suggestions on this forum to me to "cover the whole thing with a sheet and lever it out" when I was struggling with the Norton would have probably resulted in damage to one or more of my hands, the bike or surrounding items.
I appreciate this is not a Norton although plunger systems in general tend to follow a very similar pattern. I do bow to anyone here who has direct experience of the Excelsior layout. Part of the problem is possibly the terms being used.
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I’ve been reading this thread on and off as it has progressed, I have had absolutely no experience of plunger type suspension. What is confusing me is that unless I’ve missed it no one has mentioned spring compressors. Ive no idea what the cost but they are fairly easy to make from lumps of ally and stud iron.
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suggestions on this forum to me to "cover the whole thing with a sheet and lever it out" when I was struggling with the Norton would have probably resulted in damage to one or more of my hands, the bike or surrounding items.
Must be rather different to my A7 then. I did cover the assembly with old carpet and pushed it out when I was disassembling it, and rather than bits of metal flying around the workshop there was nothing but a muffled sound of springs hitting metal (frame lugs) as the tension was released. On instructions from the A7-10 forum I read that it's possible to replace said springs by hand, and indeed it is. A bit of a heavy push, but entirely possible.
The springs aren't under tremendous tension when in place as they only need compressing an inch or so to replace them.
It's not like they're a foot long and compressed down to three inches, which really would be potentially dangerous!
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Thank you to all for your input on this.
There is no pinch bolt on this plunger as I have taken them out top and bottom. I have tried left- and right-hand plungers and they have the same symptom. I believe the rod is seized into the sleeve. If I cut the rod, I will need to find a replacement which is going to be hard for me. iansoady Yes "the vertical tube feels stuck to the centre rod". Any further advise?
Delon
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The only pics I can find online are a 1954 Universal in pieces,and its clear the rods have a central spring boss added,probably threaded on..........so cutting the rod isnt a total problem,as its just a rod .........but from the pic I can see that nothing had to be cut to remove the units.........unfortunately the pics are not all that clear,but clear enough to see that my & Rex s description is substantially correct...............my suggestion now is to take the frame etc to someone who has mechanical experience and preferably old bike experience,and person will immediately see whats wrong,which I am beginning to suspect is weldmetal done by a bodger............the Pics are on Sheldons.
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Must be rather different to my A7 then.
It must be. The springs needed compressing by between 2 & 3 inches to get the assembly into place. Even putting my (substantial) weight on the main spring only compressed it about 1/2" or so - there's absolutely no way "hand pressure" would have managed it.
I think Norton designed it to be relatively uncompliant - although I have found the system to be quite effective on the road.
John - do you have a link to the picture which may help the OP? With mine, I decided that it was better to sacrifice the rod, which is a simple part, rather than risking damage to the slider which is not. Cutting the rod on the Excelsior will allow the whole lot to be removed from the frame. My new one cost me only £20 to have made (in fact I later discovered that RGM actually supply them for £30). I cannot see that the Excelsior one would be hugely more than this.
There are only a few ways a plunger system can work and as far as I can see all must involve a central shaft ("bearer rod") with a sliding member carrying the wheel spindle. There must then be springs constraining its movement, either internal as the Excelsior seems to be, or external as on the Norton. I would imagine that the Excelsior springs are held by the hexagons apparent on the pictures and that these probably unscrew to release the tension on them. But of course the external springs have been fitted (the internals maybe vanished years ago), complicating the whole matter.
I'm also not clear whether both sides are seized or only one.
Regardless, this is an interesting saga and I look forward to a resolution and all being revealed.
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Hi Ian and members,
Both sides are seized.
Ian, can I please have details of where I can buy the centre rod please?
If I can get the rods x 2. I will cut the ones I have to take the plungers out.
John K, I believe this bike has been modified to take 1 passengers hence the outer springs on the plungers top and bottom and passenger leg rest on the frame.
Thank you.
Delon
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Ian was talking about the centre rods for Nortons.
You likely will have to get excelsior ones made up, although they are nothing particularly fancy. ?
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the picture of the dismantled frame is in Sheldons EMU.......as a 1954 Excelsior Universal..............looking at the pic,I suspect the spring seat is threaded to the rod,and possibly there is a locknut.................however ,from a constructional point of view ,it would be also possible to make the rod two diameter ,and have the spring seat retained by the step between the two diameters......this method needs no thread,but has certain disadvantages...............summing up the evidence..........i would expect the central rod is "jumped up" and the increased diameter threaded for the spring seat.......the spring seat is clearly visible as a discrete unit ,secured to the central rod .
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If it was double diameter then the seat would tend to move on either bump or rebound (depending which side was which). A thread sounds likely, or even a pin through a collar?
I am 90% sure that replacements can be made and I have PM'd the OP with the email of the chap who made a very good job of mine. Let's face it, a 1950s Excelsior would have been made as cheaply as possible so there are unlikely to be fancy solutions in there.
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Gone quiet - I wonder how he's getting on.....
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I still wonder about the bloke with the French non-running moped.
(Well, all of them, actually)
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Hallo Members,
Yes, it’s been a while since I last posted. Sorry, but I had to wait for the parts book to arrive and I was hoping this will help…… it hasn’t as it only describes the parts. In the description the centre shaft and sleaves are separate and it should slide out either way. Not with mine. I believe the centre shaft is seized into the sleeve.
Which one should I cut ???? The centre shaft ???? OR the Springs ???? Do you think the springs is from the inside of the plunger that has been taken out and then put back on the outside?
How easy is it going to be for me to replace any item that I cut?
Thank you, John. K and Iansoady and all members who have advised.
I look forward to moor replies.
Delon.
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There appears to be a nut threaded onto the shaft down low there.
Have you done as suggested earlier, and tried undoing that nut ?
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Hi Members,
R, their is no nut threaded onto the shaft down low. Except for the outer 2 nuts treaded onto the shaft. Yes they have been taken out but nothing happens.
Delon.
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I'm sorry, I don't know where I got that from !
I saved a pic from somewhere, so there must be another similar enquiry someplace in a parallel universe ??
Cutting your plunger rod as mentioned would seem to be an option, if it can't be shifted.
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We're about back where we started.
A thin cutting disc in an angle grinder may get between the coils of the springs to cut through the central shaft. Then remove the top part through the hole in the frame lug, lever the bottom section complete with slider up till the rod clears the hole in the bottom lug and you should be able to - very carefully - slide the whole lot sideways to release it. But beware the spring tension.
If you can't get the cutting disc between the coils then you'll have to cut the spring as well.
You asked earlier where you could get parts made and I pm'd you a possibility. I now understand you're in Australia so as that source is in the UK probably not suitable. But don't you Aussies have a reputation for making stuff by melting old saucepans on the barbie?
There must be small machining shops in Melbourne. Here's one: http://www.natex.com.au/
Here's a spring manufacturer: http://springshop.com.au/
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Iansoady, thank you. I will try the saucepans on the barbie trick if I get stuck for parts. Ha HA!
Please see attached photo. Once I compress the larger spring (top). It gives me enough room on the small lower spring (bottom) to use a hack saw to cut the centre rod only. It should take me 2 minutes to do this. Yes, the plunger will have tension as the large spring is still compressed.
By realising the larger spring tension slowly and then sliding the plunger sideways to release it I should have it in my hand.
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Mr D, I live in Melbourne and probably have all the info and contacts you need. I also ownExcelsiors. All we have to do is work out how to do private messages on this forum so we can get discuss getting together to solve your problem.
Cheers,
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Click on the recipient's name and a profile comes up, then click on "send PM". :)
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Done it Rex. I’m having computer issues that are making communications a bit erratic.
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Keep us posted. And keep the hands and fingers out of the way!
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Thank you to all members for your input on this. Each input has been valuable to me.
I will be catching up with 33d6 sometime this weekend and will keep you all posted.
I am hoping to resolve this and get the frame painted so I can start on the project.
Happy 1st.
Delon.
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I have finally taken the plunger out of the frame. Thank you to all members for your input.
33d6, your welt of knowledge is excellent and thank you for dropping by.
I have attached a photo of the unit. The large spring and the smaller spring are what acts like a shocker. Its sits on the rod and the sleeve. There is nothing else inside the plunger. The sleeve in my plunger has been made up by placing parts of a socket set together and then brazed and the rod after several years has got stuck to the brazed sleeve. This is not original this is a Bodged Job done by someone. Cutting the rod was the only way out.
What I need to find now is how I could get the rod made up and the sleeve made up times 2. Can any of you help with this? Thank you it has been a journey with this Excelsior.
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Is the springbox saveable?...What about the endcaps?...........the rod is easily replaced ,remaking the plunger unit ,a fair job of fabrication and machining.
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Hi John. K
The end caps are fine. There are no springs inside the plunger unit. My plunger unit consist of the centre rod, the sleeve, and the large spring and the small spring. There is nothing else inside the plunger. Please see pic attached. How could I get the rod and the sleeve made up times 2?
Delon
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OK,so what does the inside surface of the tube look like..............it should be a plain cylinder ,probably with the natural finish of a solid drawn tube ..............the rods should have a thread or a boss in approx the centre ,for a spring seat to go on ........from here it looks like the rods are replaced with plain ,and springs outside...........I must say its a strange bodge,but british bikes are the natural habitat of the strange bodger,and sadly,the true bodger is becoming extinct due very high prices for new material to bodge.
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Every version of a plunger unit I've had apart has the springs sitting above and below the axle slider casting, and the central pillar/tube is the same diameter over it's whole length.