Fork Overhaul

[Greybeard]

I'm going to give the retaining cups a try. Just ordered 2 from feked and with vat and 2nd class post cost £12.54.

I'd like a report about using them please.

[RDfella]

Anywhere else stock them at a reasonable price? Stopped buying from feked unless I really have to as I'm tired of being ripped off with their postal charges.

[RogerSB]

Will certainly do, GB.

RDfella, I've wanted to buy from them before but quit out because of the high postage shown, but they automatically default your order to priority postage. At the checkout stage to the left (somewhere) there's a selection of postal choices, including 1st Class and 2nd Class. As I'm no hurry for them (driving to Monty's tomorrow for fork bits and still lots to do) I opted for 2nd at £1.95 (see the order picture).

Also British Bike Bits (Burtons) have them for £5.94 each plus postage.
https://www.britishbikebits.com/fork-retaining-ring-cup-bsa-triumph

[RogerSB]

A50 / A65 Fork bush retainer cup placed on A10 fork leg to see how it fits. Plenty of inner diameter clearance for stanchions, in my case a 0.010" shim under it to take up all up and down movement of bush. Top is slightly bigger in diameter than threads on fork leg (so a little filing needed) and thickness is 1mm - so should be a good tight fit up against the oil seal. Takes seconds to fit.

Collected the bits I need from Monty's Classic Motorcycles on Thursday evening and had the foresight to take one of my fork legs with me and a good job too as the last pair of oil seals he had one of them wouldn't screw on the fork leg as there was a some unwanted chrome on the thread. Now waiting for a pair of stainless steel ones to arrive from Barleycorn.  That is another story, which I'll tell later when more time.

[Greybeard]

So, to check my understanding: you can use these instead of the orrible circlip?

[RogerSB]

So, to check my understanding: you can use these instead of the orrible circlip?

Hi GB,
For what I can tell at the moment the answer would be yes. All they do is squeeze-fit between the the top of the bush (no circlip needed) and the oil seal to hold everything securely in place. Shims just go on top of the bush (so under under the retainer), as necessary, to take up any movement. Literally they just drop in place in a second or two. What I can't do at the moment is screw an oil seal holder, with seal fitted, all the way down on the fork leg threads to squeeze the retainer between seal and bush to see if it goes all the way down and close the gap between fork leg and oil seal holder, but I don't envisage a problem. It has a convoluted shape so it may be designed to compress as required. As mentioned the retainer's material thickness is 1 mm and the lip sits on the top of the fork leg - so that increases the measurement from the bottom of fork leg thread to top by 1mm, which may be a good thing to hold the seal tightly in place.

I'll be able to let you know when I get the oil seal holders and try it.

If Julian says they can be used - they can be used.

[RogerSB]

Spent some time filing the bush retaining cups to fit my A10s fork legs today. Had to file about .5 mm all round the circumference of the larger end for them to pass comfortably past the threads in an oil seal holder and I also eased out the smaller end to give a similar clearance between it and the stanchion, as I don't want to risk it touching and scraping the stanchions when they move up and down.   Whether it's the same old story with reproduction parts  but whether spending time filing them to make them fit is any quicker or easier than struggling with the circlips I'm not so sure  , especially as I found a fairly easy way to fit the circlips after struggling initially to fit one for an hour without success. Anyway, maybe a worthwhile exercise. Now waiting for my new oil seal holders before I can make any further progress. In the meantime I've started to dismantle the gearbox to check it.

As I'm just a self taught amateur mechanic through a lifetime of working on my own British motorcycles and classic cars and with no engineering experience I've posted a photo showing the clearance I've made and would welcome opinions by those more qualified.

[JulianS]

The widget should self centre when all assembled - the outer diameter of widget and seal should be just about the same so that widget is automatically centred by the seal holder and cannot touch the fork shaft.

[Jules]

especially as I found a fairly easy way to fit the circlips after struggling initially to fit one for an hour without success..

Hi Roger, could you recap the easy way to fit the circlips please  I have to do this soon....cheers

[RogerSB]

Hi Roger, could you recap the easy way to fit the circlips please  I have to do this soon....cheers

Hi Jules, described in my reply 7 of this topic. Once the end is clamped in place I pushed the circlip down with with a screwdriver starting from the clamped end first. Went in fairly easy - but that was without a stanchion getting in the way.

The widget should self centre when all assembled - the outer diameter of widget and seal should be just about the same so that widget is automatically centred by the seal holder and cannot touch the fork shaft.

Spot on Julian, when pointed out it becomes so obvious - but pity I never realised that before I started filing .  I was a little peeved at them being a bigger diameter than the fork leg threads and then I got carried away with the file (and lack of engineering skill). I did also open up the centre to give plenty of clearance to the stanchion and when it gets clamped up tight between bush and the oil seal I'm hoping it'll stay put.  Oil seal holders were delivered yesterday so I'm going to fit forks today (hopefully).

[RogerSB]

Progress so far: Forks assembled today and starting to connect the wiring in the nacelle.

The fork bush retaining cup (widget) was very easy to fit and everything went together well, slid the oil seal holders on stanchions, then retainer cups, shims, top bearings, bottom bearings, clamped stanchions in the yokes to tighten bottom nut, PTFE around fork leg threads and a couple of turns of string in the grove and screwed it together with an oil seal holder tool.

When I ordered the stainless steel oil seal holders from Barleycorn Engineering Simon said he'll be honest and warn me that some have had a problem with them not screwing on their BSA's fork legs. He told me he’s invested a lot of money in a business partnership with a multi million pound manufacturing company near him to manufacture them, only to have problems with the threads not being the right size for some fork legs. With some there's been no problem and happy BSA owners. Puzzled and concerned by this variation, he got together with the company he's been working with and they have carried out some tests and investigations and discovered there is a variation of seven thou in the thread diameter on bikes made by BSA in the mid 60's to the ones made in the early 50s. I can't remember if he said early 50's were the smaller or the other way around.

With my agreement he has used the oil seal holders I bought from him as a test (that’s why it’s taken so long for me to get them). His idea was to open up the thread slightly to try to eliminate the problem by making 'a one size fits all' as it's better for them to screw on easily than being too tight or not fit at all. As it seems to be successful in my case his plans are to do the same for the others he has.
 
(Edit): Referring to the above: Is this why this seller is making such a bold statement in the description?
https://www.ebay.co.uk/itm/BSA-CHROME-FORK-OIL-SEAL-HOLDERS-BSA-A-B-C-models-29-5310-Made-in-ENGLAND-S-S/282536850999?hash=item41c8823637:g:dXUAAOSwPYZU8X~C

[muskrat]

G'day Roger
Mine must have been in the Fing tight/not fit batch. I dread the day I have to get them back off.
Cheers

[RDfella]

I've had more trouble with the chrome ones. Not only do they eventually rust, but the fit is invariably all over the shop. One size fits nothing would be appropriate, in this case usually caused by varying thicknesses of chrome in the threads. PITA.

[Jules]

Hi Julian/Roger, I'm interested in looking at these for my '56 A10, but for the life of me when I google them and look at the assy diagrams from Draganfly et al for A65 I cant see where/how they fit, maybe they were only used for a short time or something?.....what am I missing here, are they that obvious how they fit and why cant I see them on the assy diagrams from Draganfly etc?? Apologies if I'm being dense here  ...
I think you are saying that they simply replace the circlip because they actually crush into place hence do away with shimming too, is that right??
can you share an assy diagram and process please...thanks
PS I did notice in the Draganfly schematics that they have an "oil scraper" that seems to fit over the seal too, is that usable on A10, (could be a useful dust seal)??

[JulianS]

The widget was used in 1966- 1968 A65 forks, plus the B25 B44 with damper rod forks.
See this diagram, it is item 24.

www.draganfly.co.uk/index.php/bsa/bsa/a50-a-a65/1966/category/254-front-forks