Fork Overhaul

[RogerSB]

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??

Jules, when I placed a top bush, with a retaining cup/widgett resting on the top of each fork leg in turn and holding the widgett down tightly I could still move the bushes up and down slightly with a finger of my other hand - so they wouldn't have been tight between the top of a bush and an oil seal.  One widgett needed 0.010" shim, the other 0.020". This was achieved by trial and error to take up all the free play but making sure the widgetts were still tight on the top of each fork leg. Maybe it was the quality of the F---d widgetts I bought because they were definitely bigger in diameter than the fork leg threads. No way would they have gone past the threads in an oil seal holder. Hence my over exuberance with a file  , but with the oil seal holder screwed down and then (with must be a technique worthy of a mention in any good engineering manual) I vigorously shook each assembled fork and I didn't detect anything rattling inside  - so presuming a tight assembly.

[Jules]

got it, thanks....still seems odd to me though that it needed a circlip to hold the bush down before, but now it doesn't, how does the widget achieve the same function? surely its just the screwing down of the seal holder onto the widget which in turn loads the bush, so why do you need a circlip on A10 at all, when screwing down the seal holder achieves the same end?? OR does it?? cheers

[RDfella]

Jules - there is a gap between bush and seal. The widget fills in that gap so the seal holder retains the bush instead of the circlip.

[Swarfcut]

Jules, you are right. The problem is that the widget will be a simple pressing, and in an ideal world each would be perfect. These days any so called new stock may not be quite as perfect as it should be, and luckily Roger realised his set needed a shim to clamp the bush, which itself may not have been as perfect as it should have been.

 Ideally, the widget should be deep enough to bridge the distance between the top of the bush and the bottom of the seal when the oil seal holder is finally tightened down, and collapse slightly to exert force to hold bush and seal in place. The thickness of the seal also has to be considered, some are marginally too shallow.

 Swarfy.

[JulianS]

Photo is cross section of A65 type damper rod fork and shows the position of the widget. Ignore the damper valve and position of bleed holes shown, they dont apply to the A10.

Fit is not always perfect, there can be some slight variation in depth of seat in the slider for top bush and also in the thickness of the lip on the top bush.

[RogerSB]

These days any so called new stock may not be quite as perfect as it should be,
 Swarfy.

Too right Swarfy!
When I bought and picked up my bits to overhaul my A10s fork legs I also bought a rear 42T sprocket stamped 'Made in the UK' to replace the one on my bike because its teeth had lost their chunky roundness and I decided on an imported rubber sealed bearing to go with it because the difference in price was £8.33 for an imported bearing or £25.00 for a UK made one. When I got home I tried the fit of the bearing in the sprocket, not to actually fit it but just out of curiosity - like you do and to my surprise it just fell in the hole. Assuming the imported bearing was at fault it was a phone call and a drive back to Monty's Classic Motorcycles. Luckily I took both sprocket and bearing with me. When I arrived Monty had already fitted the same type of bearing in the same type of sprocket, as a test. He told me he had to press it in. I turned the sprocket I had taken with me, with the bearing in hole, upside down on the counter and the bearing dropped out. Puzzled, Monty got another bearing and tried that in the sprocket, it was loose.  So it was the sprocket that was made in the UK that was at fault.  Monty's comment was, with a  look, 'Imported bearing fine, UK made sprocket not'. He also said he doesn't get too many problems like this with Triumph parts (which he tends to concentrate on more) and the reason is that all the drawings for Triumphs have been saved but when BSA closed down the workmen went in and trashed everything and the engineering drawings were burnt. How true? I tend to believe Monty, maybe somebody on here will know for definite.  If it is the case it may help to explain why we have so many problems with re-manufactured parts.

[JulianS]

My new sprocket experience was a bit different - the bearing/sprocket fit was so tight the bearing just would not fit. Tried bearing in a new old stock sprocket and it fitted perfectly.

Such significant variations in the sprockets are a quality control issue for the manufacturer.

[RDfella]

Roger - Can’t see that lack of drawings is the reason. If you are making a part but don’t have the drawing, you don’t just makes holes any size – you find out what the hole is for and make the size accordingly.
Problem is more likely due to the UK fast becoming a 3rd world country. All the engineering we once had has been relocated to the EU, assisted by massive EU grants and sweetners.

[berger]

JulianS same here with bearing , brother had to take a bit out of new sprocket , bearing ok in original one

[RogerSB]

Roger - Can’t see that lack of drawings is the reason. If you are making a part but don’t have the drawing, you don’t just makes holes any size – you find out what the hole is for and make the size accordingly.
Problem is more likely due to the UK fast becoming a 3rd world country. All the engineering we once had has been relocated to the EU, assisted by massive EU grants and sweetners.

I think the reasoning behind it is that the various manufacturers are taking measurements from parts to make more parts, as opposed to following the original engineering drawings with one lot of specifications. Just my take on it.

(Edit): Regarding the replacement parts for my fork overhaul and new rear sprocket, to sum it up: Oil seal holders did not fit fork leg threads, A65 fork widgetts that can be used in place of circlip did not fit without some modifying and the sprocket bearing hole was the wrong size for the bearing - says it all!

[RogerSB]

Just reporting back on my recent fork overhaul, as promised.

I took my G/Flash off its work platform earlier this evening, where it's been for a month and took it for a good test ride. I'm pleased and relieved to say everything felt smooth and correct, so I've returned home a happy bunny  . The forks operated smoothly with no knocks or unusual noises, even though I tried to find as many bumps as possible to test them (it's sods law how scarce they become when you want one to ride over).  So my conclusion is that the A50/A65 fork bush retainers (widgetts) in place of the awkward circlips seem to work perfectly and is a quick and easy way to secure the top bushes in place - as long as you buy ones that are made to the correct size. In my case buying ones that were not quite correct resulted in me having to spend time with a file because they were slightly too big in diameter to fit into the oil seal holders. If I didn't have to do that they would have been a piece of cake to fit as they just need to be slipped onto the stanchion between the oil seal holder and top bush (and that would take only a couple of seconds) before screwing everything together.

I also took the opportunity to change the rear sprocket for a new one, removed the gearbox inner cover to check if anything was amiss inside and swapped the cover with one I obtained last year to which I had fitted a new mainshaft bearing and bushes.  Also removed the old paint from the front fork legs, trousers, front mudguard, its fixings, the front hub cover and both brake back plates, rear mudguard and number plate, replacing all the nuts, bolts and washers I had to remove with stainless steel ones.

So now hoping for some decent weather!