On the front lower link of the girder forks, (the one the spring sits on and the mudguard is mounted from), should there be a grease nipple?
If not, how do you get the grease/oil into the bush spindle?
Thanks Ron,,, I found a paint filled hole there. Dont suppose you know what thread the nipple is do you? I will run a tap through it and get a nipple
Cheers
Interesting..maybe that is another one I have misidentified, like I did with the speedo studs for a number of years.. . Saying that BA threads are usually on instruments and electrical components in motorcycle applications..With 0BA having an OD of .236" and a pitch of 25.4 TPI and 1/4" BSF having an OD of .250 and a pitch of 26 TPI these two are easily confused (as previous threads have shown)..Clarification required again... ...Ian
I dunno, you'd have to ask BSA that question.
I thought it was the usual 1/4 BSF when I removed it (for the overpainting to be removed) but testing it with my trusty BA thread plate showed it to be 0BA.
These two threads may be similar to the naked eye but they sure ain't interchangeable...
Some post war BSAs used 2 BA grease nipples..Bantam, C15, B40. No reference to O BA so far, though earlier publications don't mention anything about grease nipple threads..including the military Inspection Standards book for the M20...I'm pretty sure wartime and early post war models used BSF as they fit without any problems despite being .014" bigger on the OD than 0BA...Pre war?..no idea at present apart from Kevins observations..Another question for Leon perhaps as he is into bikes of that period.Ian
Yes. Underneath off centre towards the damper end.
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The position of the grease nipples has often been questioned but BSA knew that a central positioned greasing point pushes clean grease from the centre outwards.
The bottom yoke has one for each bush only because the steering damper makes a central grease point impossible.
Anyone considering installing a grease nipple for each bush must periodically clean dirty grease from the centre of the top yoke & fork blade bushings. But BSA's thinking is better it just means taking the weight off the forks to get even greasing.
Are you sure your thread hadn't been tapped for 6mm? 0BA and 6 mm can be interchanged and 6mm would be an easy one for someone to get hold of if they hadn't got any BSF/Cycle nipples
I'm not keen on the 'central nipple' idea for lubricating the bushes. In my experience if bush wear is uneven (or bush to link clearance when fitted) the grease will take the easiest path through the bush with the greatest clearance at the expense of the other one.
This has happened on my M20 in the period since the last time the forks were overhauled...One link pin is rusty and the bush dry, the other oozes grease when lubricated.
I plan to fit a nipple for each bush to get guaranteed, direct lubrication when I rebuild the bike in the Autumn...Ian
I'm not keen on the 'central nipple' idea for lubricating the bushes. In my experience if bush wear is uneven (or bush to link clearance when fitted) the grease will take the easiest path through the bush with the greatest clearance at the expense of the other one.
This has happened on my M20 in the period since the last time the forks were overhauled...One link pin is rusty and the bush dry, the other oozes grease when lubricated.
I plan to fit a nipple for each bush to get guaranteed, direct lubrication when I rebuild the bike in the Autumn...Ian
Air Publication spare parts list for contracts C10655 & C14052, dated Jan 1944, lists TT/P6/ ¼” BSF under the Proprietary Part No. column for this grease nipple, and all other similar ones as far as I can see. The TT bit will be some abbreviation of the manufacturer or supplier (e.g. they used LU for Lucas, AM for Amal, RE for Reynolds, HN for Hoffman etc etc) but I can’t think who TT would be. Anyway, 1/4” BSF is what they were in 1943-1944 at least.
I just bought some nice stainless ones for my upcoming rebuild...Lovely, lovely stainless..OOOH....Ian
With the correct form, Ian ? I know some don't like these older style nipples with a view to lubrication but I find that my 'Blue-Point' high-pressure gun goes onto the nipples quite successfully. In fact, the biggest problem is not forcing it through the side damper discs.