Hi guys, I notice on the right hand fork a loose bronze looking bush sitting on top of the chrome notched tube ...does this mean it's been reasembled wrongly in the past, or somethnig else?
Any help would be appreciated.
I can't work out your description , sorry.
Any pictures would help
Hi,
Try and post a photo. Is this bush loose or just visible? There should not be a bush above the castellated chrome nut/tube.
Dave.
https://draganfly.co.uk/product-category/bsa/sparesparts-for-bsa-c15/front-forks-c15/
are you talking about 40-5014 above the top oil seal holder ??
(https://draganfly.co.uk/shop/65284/cover/#40-5014)
Hi, the bush is loose and sitting between the black fork shroud and the chrome notched tube.
If I lift it up a bit it reveal a noticable lip to the botom of the bush.
Incidiently, I've been trying to upload a photo but can't for the life of me find how to attach it.
Thanks.
A photo at last.
have a look at the links I posted above to see the assembly order
Does that mean it's the 40-5014 cover that I'm looking at in the photo?
There doesn't appear to be one on the other fork?
Thanks.
it looks the same sort of shape
from memory , I can't remember my 2 x C15 s having anything above the upper seal - some forks have 2 x seals in that chrome holder
my other parts book shows 40-5068 COVER on top of the upper oil seal (and there are 2 seals) - my question is what is it covering? and what holds it in place ?
There is nothing obvious in the way of securing it to the oil seal holder - unless it literally slides up and down with the leg - and COVERS the upper seal from any ingress of muck
There's definately nothing holding it in place and is free to move up and down. Given the chrome part has notiches in it, there seems little point in the bush attempting to stop junk gwetting in to the top seal.
Looking at a picture of a new bush set online, what on my bike looks remarkably like 40-5019 top bush that should be under the chome seal holder.
I do find the exploded view of the fork parts a little confusing, in that there's a cover showing above the seal holder that also looks like a 40-5019, though it's defined as being a 40-5014.
Confused? you bet!
Mike.
Based on my 1965 C15, I would say that the 'top hat' bush in your piccies is upside down. And should fit in the top of the slider. On one of my piccies attached where the stanchion is in the slider, you can just see the brass ring at the top of the bush showing. The other piccie show a stanchion with the bottom bush still in place, and the top bush removed. On the bench there are two new top bushes, two new bottom bushes and one removed (old) top bush.
Hope this helps.
does this link work ??
https://partsbooks.britishonly.com/partsbooks/PDF_Files/BSA/sectionC_BSAservicesheetno426.pdf
you can JUST see the outline of your part in this service sheet
https://partsbooks.britishonly.com/partsbooks/PDF_Files/BSA/sectionC_BSAservicesheetno426.pdf
40-5140 is shown as a DUST COVER above the top oil seal
the 2 seals per leg live in the oil seal holder with castellated top
this holds the top bronze bush in place in the top of the sliding leg
I think it is meant to look like this where your loose bit is pushed inside the oil seal holder
https://www.britishmcparts.com/suspension/forks-stanchions-oil-seals-oil-springs-ajs-matchless-bsa-mprtpm-triumph/bsa-forks-parts-stanchions-gaitors-bushes-oilseals/-fork-oil-seal-holder-bsa-c15-ss80-40-5013-40-5139.html
https://www.britishmcparts.com/suspension/forks-stanchions-oil-seals-oil-springs-ajs-matchless-bsa-mprtpm-triumph/bsa-forks-parts-stanchions-gaitors-bushes-oilseals/-fork-oil-seal-holder-bsa-c15-ss80-40-5013-40-5139.html
and finally
https://www.bsaunitsingles.com/item.wws?sku=40-5140
I just had a look at it with a torch and can cleaerly see the oilseal in both forks and they look fine and clean.
This prmompted me to jack the bike up to release the front wheel from the floor, following which I tugged and pushed the forks, finding no evidence of play whatsoever.
I'm begining to feel that if a top bush was not in it rightful place, it would show with a degree of slop or movement. So I'm thinking everything is as it should be, and this odd loose bush was left on or put on by accident during reasembly and they couldn't be bothered to pull the fork leg to remove it.
Incidently, I did knock the bike off of its centre stand and load the front forks, rocking the bike back and forth to the point of grounding them. Everything seems stable and true without any clonks or unusual noises.
I'm inclind to remove the fork entirely and remove the bush, since it service no function. And while I'm at it,
drain and refil the fork oil.
The bike clearly show signs of being restored with many new parts, new tires, electronic ignition, tons of comp etc, so I imagine the frorks will have had bushes and seals.
Shame they didn't make a better job of the paintwork, it's shiny but a bit naff here and there. but hey ho, I'm happy with it and it gives me something to
work towards.
Cheers,
Mike.
Further to my #10 above, it looks as though your oil seal holder (40-5139) is separated from the dust cover (40-5140) - which is not normal. So you have two anomalies.... I think two anomalies in one little glimpse would make me very interested in seeing how the the other parts of the forks have been assembled.
I'd highly recommend the Rupert Ratio books if you don't already have them.
Well I've learned a bit more, in that what I have is the early type single seal holder.
BSA made a mod to the notched holder by mounting a further tube and seal on top of the notched bit.
As was illustrated in Tigerfeet's pics, there should be the lip of the top bush just visable above the lower section, where the seal holder screws on. There really shouldn't be any other items above the tube. (on the early type that is.)
Now I'm inclined to buy the moded seal holders and sort the forks out once and for all.
It looks like we arrived at the same realisation at the same time Tigerfeet.
I'll have a look for the book you mentioned. Thanks for the info.
Quote from: Tigerfeet on 04 Sep, 2026, 17:46 Further to my #10 above, it looks as though your oil seal holder (40-5139) is separated from the dust cover (40-5140) - which is not normal. So you have two anomalies.... I think two anomalies in one little glimpse would make me very interested in seeing how the the other parts of the forks have been assembled.
and
I'd highly recommend the Rupert Ratio books if you don't already have them.
Do check my links as they show your loose tube pressed into the holder
Hi ryhatt, yes indeed, your photos clearly show what's missing from my bike.
Ive now ordered a set and have also ordered a Rupert Ratio book 2.
Many thanks to you and everyone else for your help in putting me on the right track.
Cheers,
Mike.
This might help: https://www.youtube.com/watch?v=xpj-BTOCfVM
I would not rust the workmanship on the bike until everything was checked. The problem you have is odd and there may other equally odd things not so visible.
There is one detail that bothers me.
When the bike is on its centre stand, the forks expand to such a degree that the stantions are visible above the chrome seal holder.
When I look at other pictures of c15's on their stand, only the chrome seal holder is visible, which suggests the entire plunge depth is great than one would ecpect.
I'm not entirely sure Whether this is mechanically possible?
Even those that have the upper seal section in place, do not appear to reveal the upper section when on the stand.
I do intend to strip the forks entirely,to make absolutely sure all is as it should be.
The Rupert Ratio book will prove it worth when it finally arrives.
I bought a non-runner (Matchless) with the description "should just need ignition timing to get it running". It may or may not have needed that but it had the oil pipes connected wrongly and the oil tank was full of metal. The engine had been rebuilt and had I not checked everything I would have had to rebuild it again. It took weeks of frustration to find the reason why I could not get a decent idle was the Monobloc had a Concentric needle which is about 3/8" longer.
Assume nothing!!
I generally assume that any old bike I buy will need extensive mechanical work and have rarely been wrong. If I was buying, I'd look for one that had had the cosmetics done well as this is (a) more expensive and (b) less interesting as far as I'm concerned than mechanical work. Like others I've come across some real horrors in my time but hope I haven't perpetuated any. But far back in the mists of time whatever got me mobile at the lowest cost was what counted.
Quote from: Jazzman on 06 Sep, 2026, 16:22 When the bike is on its centre stand, the forks expand to such a degree that the stantions are visible above the chrome seal holder.
When I look at other pictures of c15's on their stand, only the chrome seal holder is visible, which suggests the entire plunge depth is great than one would ecpect.
Probably the bush we see in the picture is actually the bush that should be the other way up and fitted into the top of the lower section. In its correct location it, and the tube spacer, limit the distance that the bottom section can move downward.
Everything on the bike works well and riding shows little or no perculiarlies. Gears are fine along with the clutch.
The engine itself is very clean and with lots of comp'. No exaust smoke etc.
The bike came to me with the ignition in pieces. The chap was converting it to electronic and go completely lost with the wiring and inmstalling the new kit.
Once I had it sorted, it fired up and runs a treat. Ticks over sweetly and pulls when you ask it to.
New seat, tires andf powder coated wheels. Brakes are fine and all lighting and charging works as it should.
Paintwork is 75% decent, not showroom but decent.
This just leaves the oddity that is the forks. As I said earlier, I will fully strip them and see what we have.
Hopoefully no mega expensive dramas.
Time will tell!
Quote from: Tigerfeet on 04 Sep, 2026, 15:05 Based on my 1965 C15, I would say that the 'top hat' bush in your piccies is upside down. And should fit in the top of the slider. On one of my piccies attached where the stanchion is in the slider, you can just see the brass ring at the top of the bush showing. The other piccie show a stanchion with the bottom bush still in place, and the top bush removed. On the bench there are two new top bushes, two new bottom bushes and one removed (old) top bush.
Hope this helps.
I agree, the bush is upside down and should fit into the top of the slider under the chrome oil seal holder. Interestingly if you look at the draganfly site for C15 front forks the exploded diagram shows it like the photo with the bush the wrong way up sitting on top of the oil seal which is wrong. I wonder if both legs are assembled like this?
Quote from: Jazzman on 06 Sep, 2026, 20:39 Everything on the bike works well and riding shows little or no perculiarlies. Gears are fine along with the clutch.
The engine itself is very clean and with lots of comp'. No exaust smoke etc.
The bike came to me with the ignition in pieces. The chap was converting it to electronic and go completely lost with the wiring and inmstalling the new kit.
Once I had it sorted, it fired up and runs a treat. Ticks over sweetly and pulls when you ask it to.
New seat, tires andf powder coated wheels. Brakes are fine and all lighting and charging works as it should.
Paintwork is 75% decent, not showroom but decent.
This just leaves the oddity that is the forks. As I said earlier, I will fully strip them and see what we have.
Hopoefully no mega expensive dramas.
Time will tell!
The fork leg is assembled wrongly, it looks as though someone followed the exploded picture on the draganfly site which shows the top bush, upside down on top of the oil seal. This utube vid will probably make it clear https://www.youtube.com/watch?v=xpj-BTOCfVM. You shouldnt need to completely strip the forks, just take the fork out the yoke, I just clamped mine in a vice by the bottom casting. Slide off the bronze bush and then unscrew the chrome seal housing, I think the correct tool is a c spanner if you have one, Rupert Ratios book suggests clamping a jubilee clip round it then it may unscrew by hand or gently with a pipe wrench or similar. Slide the oil seal off then slip the bush on with extended bush uppermost, it will sit in the top of the slider then slip the oil seal back on, retighten and you're done. If one side is wrong then there is a good chance that the other is also wrong. I'm in the process of rebuilding a long dismantled C15 and rebuilt the forks a few weeks ago so its all fairly fresh. Oh and there is oil in the fork so either drain put the right amount back or maybe keep the stantion end up a bit so it doesnt come out. ;D
Quote from: Jazzman on 06 Sep, 2026, 16:22 There is one detail that bothers me.
When the bike is on its centre stand, the forks expand to such a degree that the stantions are visible above the chrome seal holder.
When I look at other pictures of c15's on their stand, only the chrome seal holder is visible, which suggests the entire plunge depth is great than one would ecpect.
I'm not entirely sure Whether this is mechanically possible?
Even those that have the upper seal section in place, do not appear to reveal the upper section when on the stand.
I do intend to strip the forks entirely,to make absolutely sure all is as it should be.
The Rupert Ratio book will prove it worth when it finally arrives.
Could the spacer that sits between the top fork bush and the bottom bush be missing?
Its absence would allow extra fork travel.
Quote from: Kev D on 19 Sep, 2026, 21:55 Quote from: Jazzman on 06 Sep, 2026, 16:22 There is one detail that bothers me.
When the bike is on its centre stand, the forks expand to such a degree that the stantions are visible above the chrome seal holder.
When I look at other pictures of c15's on their stand, only the chrome seal holder is visible, which suggests the entire plunge depth is great than one would ecpect.
I'm not entirely sure Whether this is mechanically possible?
Even those that have the upper seal section in place, do not appear to reveal the upper section when on the stand.
I do intend to strip the forks entirely,to make absolutely sure all is as it should be.
The Rupert Ratio book will prove it worth when it finally arrives.
Could the spacer that sits between the top fork bush and the bottom bush be missing?
Its absence would allow extra fork travel.
Quote from: Kev D on 19 Sep, 2026, 21:55 Quote from: Jazzman on 06 Sep, 2026, 16:22 There is one detail that bothers me.
When the bike is on its centre stand, the forks expand to such a degree that the stantions are visible above the chrome seal holder.
When I look at other pictures of c15's on their stand, only the chrome seal holder is visible, which suggests the entire plunge depth is great than one would ecpect.
I'm not entirely sure Whether this is mechanically possible?
Even those that have the upper seal section in place, do not appear to reveal the upper section when on the stand.
I do intend to strip the forks entirely,to make absolutely sure all is as it should be.
The Rupert Ratio book will prove it worth when it finally arrives.
Could the spacer that sits between the top fork bush and the bottom bush be missing?
Its absence would allow extra fork travel.
Quote from: Kev D on 19 Sep, 2026, 21:55 Quote from: Jazzman on 06 Sep, 2026, 16:22 There is one detail that bothers me.
When the bike is on its centre stand, the forks expand to such a degree that the stantions are visible above the chrome seal holder.
When I look at other pictures of c15's on their stand, only the chrome seal holder is visible, which suggests the entire plunge depth is great than one would ecpect.
I'm not entirely sure Whether this is mechanically possible?
Even those that have the upper seal section in place, do not appear to reveal the upper section when on the stand.
I do intend to strip the forks entirely,to make absolutely sure all is as it should be.
The Rupert Ratio book will prove it worth when it finally arrives.
Could the spacer that sits between the top fork bush and the bottom bush be missing?
Its absence would allow extra fork travel.
Quote from: Kev D on 19 Sep, 2026, 21:55 Quote from: Jazzman on 06 Sep, 2026, 16:22 There is one detail that bothers me.
When the bike is on its centre stand, the forks expand to such a degree that the stantions are visible above the chrome seal holder.
When I look at other pictures of c15's on their stand, only the chrome seal holder is visible, which suggests the entire plunge depth is great than one would ecpect.
I'm not entirely sure Whether this is mechanically possible?
Even those that have the upper seal section in place, do not appear to reveal the upper section when on the stand.
I do intend to strip the forks entirely,to make absolutely sure all is as it should be.
The Rupert Ratio book will prove it worth when it finally arrives.
Could the spacer that sits between the top fork bush and the bottom bush be missing?
Its absence would allow extra fork travel.
Missing spacer does seem like the logical cause
Is the bush upside down?
Just re-bushed the forks on my B31,(I know not a C15) but the lip on the top bush fits into the bottom leg.
Also is there a spring clip missing?
Well after a long layoff, I finally got to taking the forks off the bike.
It now transpires that the forks had been overhauled with new seals and bushes, but for whatever reason, they fitted the top bushes upside down on top of the chrome castlated seal holders.
When I unscrewed the seal holders it revealed the spacer with their heads about 3/8ths of an inch poking out the top of the thread into the seal holder.
THe bushes are now in their righrful place, and just awaiting new seals to arrive for the two secondhand dustcovers I bought recently.
All the best,
Mike.
Quote from: Jazzman on 02 Oct, 2026, 18:23 Well after a long layoff, I finally got to taking the forks off the bike.
It now transpires that the forks had been overhauled with new seals and bushes, but for whatever reason, they fitted the top bushes upside down on top of the chrome castlated seal holders.
When I unscrewed the seal holders it revealed the spacer with their heads about 3/8ths of an inch poking out the top of the thread into the seal holder.
THe bushes are now in their righrful place, and just awaiting new seals to arrive for the two secondhand dustcovers I bought recently.
All the best,
Mike.
Well done. That's excellent news. The mysteries of the redundant top bush and extra fork travel solved!