Hi All. Whilst attempting to refit the petrol tank correctly without a stack of washers for spacers. Could someone please advise the correct order of the cup, rubber washer and top hat spacer and where the tank flange fits between them. Thanks in advance. Pete

The cup goes on first with the open side out, the rubber washer goes on the top hat piece and sits inside the cup. The correct lengths bolts must be used to avoid contact with the steering stem. The bolts are 5/16 BSC with a reduced hex. Click to expand image. Ron

email (option): ronpier@talk21.com

I agree thats the correct logical way to do it, however I had a "discussion" with Stuart Bray a few years ago after seeing one of his BSAs with the cup on the outside. I checked all the pictures I could find and the India Office pictures did seem to back up his theory.

Rob

email (option): robmiller11@yahoo.co.uk

Ron's way.



Mark about to get a spanner.

email (option): pes.sales@btconnect.com

Rob here is a better scan of the India bike. It's the same as the BSA drawing. What does Stuart know about M20's Ha Ha! Ron

email (option): ronpier@talk21.com

Well done Ron, that proves the point.

Rob

email (option): robmiller11@yahoo.co.uk

The rear of the tank is rubber mounted to insulate it to an extent from vibration...The obvious intention would be to achieve the same result with the front mounting (though perhaps to a lesser degree)...Taking that into account the 'top hat' passes through the rubber, cup and front tank mounting bracket and is clamped against the steering head boss by the bolt as it is tightened...The cup sits against the tank lug and is held there only by the pressure exerted on the rubber by tightening the bolt through the top hat...The front of the tank is then free to move. However, this is limited by three factors which determine the pressure on the rubber....
1) The length of the 'top hat' section on its reduced diameter...2) The thickness of the rubber...3) the fit of the tank to the frame...

My own opinion is that the design is not quite right...Using the thickness of the original rubbers as being correct and assuming the tank front brackets sit as close to the mounting bosses on the steering head as possible, but with a small clearance to allow the tank to move, the rubber is over compressed when the bolts are tightened...That is because the top hats are too short...To correct that I remake the top hat pieces with the reduced section a little longer until the tank can actually move when everything is assembled and tightened up...This involves careful measurements of all the parts and a test being carried out with the rear tank mounts removed after fitting...
When the operation and purpose of the assembly is considered it is plain that to reverse the assembly would ensure it didn't function as intended, or at all in fact...Ian

email (option): ian@wright52.plus.com

Good Evening All. Many Thanks for all of your input, this has re-affirmed my thoughts. I had looked at the parts and from an engineering point of view, thought that was the correct order in fact the only order that offered any degree of flexible mounting at the front end albeit very limited. I think that when I get it refitted, I will consider the mod to the top hat as mentioned. Thanks, again. Pete

There are some photos of Australian m20’s which seem to show a different assembly & rubbed front tyres too

If I find the photos - I’ll ping them to someone who can download them
Br
Jo’b

email (option): jonnyob1@googlemail.com

John it's "RIBBED" for better satisfaction.....Although it could be "RUBBED" :blush:

These Ozzy bikes look like Ribbed front tyres? Ron

email (option): ronpier@talk21.com

You’ll be blocked by the admins Ron !!
😃
I sent you some additional photos
See what you think
Br
Jo’b

email (option): jonnyob1@googlemail.com

Cheers John. I've zoomed in on those pictures (They don't crop very well) But I can clearly see that they are mounted in the conventional way.

Ron

email (option): ronpier@talk21.com

Is anyone making these front tank fittings complete.

Tim Drags have all the parts
https://draganfly.co.uk/product-category/bsa/sparesparts-for-bsa-a710-b3133-c101112-m202133/oil-petrol-tank-abcm/petrol-tank-mountings/

And I think so does Les at Russell's. He has the original (white) rubbers.
How is the Triton going?

Ron

email (option): ronpier@talk21.com

Thanks Ron, will check out the stock for these. McCandless Triton is finished, will send you a pic PM.

This should help.

https://pesltd.uk/?product=27-8449
https://pesltd.uk/?product=28-2338
https://pesltd.uk/?product=27-8448
https://pesltd.uk/?product=27-8447

Mark

email (option): pes.sales@btconnect.com

Interestingly, the Draganfly parts drawing shows the front mountings assembled with the cup on the outside as well...I can't see how it would function like that and personally think that is a draughtsmans error...Ian

email (option): ian@wright52.plus.com

I also noticed that Ian, as you say it wouldn't work like that. All parts just ordered from Mark at PES, thanks for listing Mark.

Think it all depends on the thickness and shore of the rubber used.

In my eyes a very simple and clever design with main feature that the bolts can be fully tightened ( so no risk of loosing it )and the tank still free to move.

BR Michiel

Thanks for the order Tim.

Mark

email (option): pes.sales@btconnect.com