The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: AdrianJ on 15.09. 2019 20:53

Title: Plunger petrol tank mountings.
Post by: AdrianJ on 15.09. 2019 20:53

I'm getting to the end now and replacing the tank.
Unfortunately the PO used a 10mm stud and some hose as the rear mountings.
A brief exploration shows that the correct items are unavailable.
I can make myself a new 3/8 stud easily and won't have a problem turning up the two spacers except that I don't know their dimensions.
I could do with knowing their length, o/d and the diameter and depth of the lip at one end.
Any assistance would be gratefully received.
Regards,
Adrian

Title: Re: Plunger petrol tank mountings.
Post by: Swarfcut on 16.09. 2019 08:52

Adrian, these spacers are not super critical and as long as the end dimensions are wide enough to give support, that's fine. The length required will depend on the tank, the later tank has rubber bushes, and over time these will have changed shape from original, so chose a spacer length which does not put any strain on the tank, find a dimension by trial and error. I may be wrong, but I doubt very few of the original spacers survive. The threaded bar trick does the job but upsets the purists.

Swarfy.

Title: Re: Plunger petrol tank mountings.
Post by: AdrianJ on 16.09. 2019 09:17

Thanks Swarfy,
I think I have really reconciled myself to trial and error.
My rubber bushes have disappeared, but I think I can make some from hose.
As far as the stud is concerned I'll make a new one. I feel unhappy about having metric components on the bike  and don't want to carry an extra set of spanners.

Title: Re: Plunger petrol tank mountings.
Post by: Rex on 16.09. 2019 11:29

Good man! Nothing worse than seeing some nice old bike with B&Q cheap metric fasteners holding bits on.

Title: Re: Plunger petrol tank mountings.
Post by: muskrat on 16.09. 2019 11:51

G'day Adrian.
Mine may be a little different in that it's a 51 A7 with the smaller tank with only rubber in the front mounting (the frame is the same). My spacers are as per pic.
Cheers

Title: Re: Plunger petrol tank mountings.
Post by: duTch on 16.09. 2019 12:54

 

Quote

......Nothing worse than seeing some nice old bike with B&Q cheap metric fasteners holding bits on..

  But no one mentioned metric before Adrian- I've seen various imperial threads available in threaded rod I used Whitworth myself.....

 

Quote

....I feel unhappy about having metric components on the bike  .....

Title: Re: Plunger petrol tank mountings.
Post by: muskrat on 16.09. 2019 14:32

G'day Adrian.
Go to your local pushbike store and get a 3/8 axle. It has cycle thread both ends and cut length to suit. They have 5/16 as well and the nuts are flanged.
Cheers

Title: Re: Plunger petrol tank mountings.
Post by: AdrianJ on 16.09. 2019 14:55

Thanks everybody,
I'll try and sort it tomorrow.
If I can't finish tomorrow It'll have to be next week as I am away for a few days.
I'm hoping that this is the last thing before riding the bike!
Regards and thanks again,
 Adrian