The BSA A7-A10 Forum

Technical => Frame => Topic started by: AWJD on 30.07. 2019 09:31

Title: 1961 A10GF Tank Mounting
Post by: AWJD on 30.07. 2019 09:31
I restored my A10 quite a few years ago but never quite got around to finishing off the tank although I did get it re-chromed. I think at the time, my painting skills were not up to the job and so I put it to one side. However, those skills are now up to a reasonable standard and so I painted the tank over the weekend.

However, I'm struggling a little to work out exactly how the tank is mounted being more used to those on unit singles and the A65. In the case of the A10, I understand what the central bolt does and what the side rubbers do but I'm unclear as to what the two rubber pads (42-8049/51) are for. For example, do they simply wrap around the top tube to prevent direct contact with the tank? I haven't tried to fit the cross brace (67-8055) yet but I assume it is simply just that and does not connect to the frame as is the case with the A65? I would be very grateful if someone could clarify the tank is fitted for my 1961 GF.
Title: Re: 1961 A10GF Tank Mounting
Post by: RogerSB on 30.07. 2019 11:26
The two pads go on the frame to cushion the tank, one in front of the tank bolt mounting and one behind it and cover it completely from end to end. Mine extends about half way down each side of the frame tube and are stuck on (some, I believe, secure them with tape). Going by memory mine are about 4-5 mm thick and are of a soft spongy rubber. You can just see the end of the front one on my 1960 G/Flash (red arrow) poking out from under the front of the tank.

Cross brace self explanatory in photo.
Title: Re: 1961 A10GF Tank Mounting
Post by: Swarfcut on 30.07. 2019 12:06
Roger, looks like your circular rubber buffers 42-8052 are away today. Early tanks just have  rubber pads that sit on the top tube. Later models have horseshoe shaped rubber  buffers that fit fore and aft on the top tube, the tank pushes down onto them. The  circular buffers mentioned fit in the pressing below the top tube and prevent the tank from rolling sideways, relieving sideways strain on the central securing bolt.

 Swarfy.
Title: Re: 1961 A10GF Tank Mounting
Post by: RogerSB on 30.07. 2019 13:14
Roger, looks like your circular rubber buffers 42-8052 are away today.
 Swarfy.

Hi Swarfy, They're there, but you just can't see them  *smile* (old photo - just to show AWJD the cross brace).
Title: Re: 1961 A10GF Tank Mounting
Post by: AWJD on 30.07. 2019 14:54
Many thanks for the feedback. As far as I can see, all 1958-on A10's used the 'rubber' pads to support the weight of the tank on the top tube. I would have much preferred to use horseshoe shaped rubbers as used on later BSA's but these would presumably have raised the tank too high.

I was tempted just to use some thick rubber matting for the A10 but, having looked at the proper mats currently available, they appear to be quite thick (>10mm) and may be made from a layer of rubber and a layer of foam - perhaps with the rubber layer taking the weight of the tank and the foam layer taking out any sideways play on the top tube. I've therefore ordered 2 x of the front mats (42-8049) and 1 x of the rear mats (42-8051).
Title: Re: 1961 A10GF Tank Mounting
Post by: Swarfcut on 30.07. 2019 18:15
A 1961 Model is near the end of the line and would  originally have had the horseshoe rubbers, by my reckoning, rather than the pads. All depends on the underside profile of the tank, and whether that is original for the model year.

Swarfy.
Title: Re: 1961 A10GF Tank Mounting
Post by: AWJD on 31.07. 2019 11:27
I struggled to find a parts book covering a 1961 A10 model with 1959 being the closest I could get to it. I looked at a 1960 Goldstar catalogue which still had the use of the pads but it wouldn't surprise if the A10 changed to the A65 horseshoe shaped buffers when this bike was introduced in 1962. However, what was used on the 1961 A10 remains unclear to me.

I'm not sure whether you can tell from the tank's tunnel profile as to whether it was designed for pads or the horseshoe shaped buffers - as far as I can see, either approach would work in principle, at least with my tank which I am sure is original to the bike. At the moment, I'm inclined to use the pads simply because this will mean the weight of this old tank is supported along the whole length of the tunnel rather the ~40mm width of two horseshoe shaped buffers.
Title: Re: 1961 A10GF Tank Mounting
Post by: JulianS on 31.07. 2019 13:15
Pads not horseshoe rubbers.

No room for horseshoe rubbers.

Below from 1960 on parts book.

Dont forget there are parts books available on this forum.

www.a7a10.net/forum/index.php?topic=12471.0

Title: Re: 1961 A10GF Tank Mounting
Post by: a10gf on 31.07. 2019 13:32
& try this https://www.a7a10.net/forum/index.php?topic=12504.msg98203
Title: Re: 1961 A10GF Tank Mounting
Post by: AWJD on 31.07. 2019 14:22
Pads not horseshoe rubbers.

No room for horseshoe rubbers.

Below from 1960 on parts book.

Dont forget there are parts books available on this forum.

www.a7a10.net/forum/index.php?topic=12471.0
The horseshoe shaped rubbers I have appear to fit quite well - these were probably left over from a BSA unit single or twin. However, I've since found parts diagrams purporting to cover the complete period 1960-63 and they all show the use of rubber pads which is what I will use. Many thanks for all the feedback which is fully appreciated.
Title: Re: 1961 A10GF Tank Mounting
Post by: Swarfcut on 31.07. 2019 15:42
My bike came with horseshoe rubbers. It has the later primary chain case with the additional access plug  for the clutch springs and in other respects has features associated with a late production model of post 1960 eg. arrow head single piece rear mudguard stays.
   So, I assumed all were like mine.  V5 not to hand, otherwise I could provide a registration date for reference. Reg no is " numbers then letters."
 Sorry if I muddied the water a bit, but comments were offered in the light of my experience. Looks like mine is not to published data, or has been messed with sometime in the distant past.

 Anyone else got horshoe tank mountings from new, or know if this was an alternative/modification commonly used?

 Swarfy.
Title: Re: 1961 A10GF Tank Mounting
Post by: AWJD on 31.07. 2019 17:00
I honestly wouldn't be too concerned over this issue especially when you consider the A10 and A65 overlapped in production for two years (62 & 63) with BSA trying to run down the A10 parts stock over this period. They could well have run out of rubber pads at some point and simply switched to using horseshoe shaped rubbers? From what I have available, it looks as though the parts book may not have changed over the period 1960-63 and may not have fully reflected some of the parts used in production towards the end.
Title: Re: 1961 A10GF Tank Mounting
Post by: RogerSB on 31.07. 2019 21:16
AWJD, Sluggo instigated a section on here for parts list in Service Literature, Scans, Links, Documents. It's here:-
https://www.a7a10.net/forum/index.php?topic=12471.msg97833#msg97833

  *wave* A10 1960 - 1962
My contribution was to submit a parts list I originally produced for my own use to cover my 1960 G/Flash (In Reply #1).  It covers all A7s & A10s from 1960 to 1962, but I didn't include export models.   All the illustrations were cleaned up and the parts list completely re-typed into a different format to make it far easier to refer to than BSA's original parts list (which I always found difficult to cross reference the part names and numbers when they're on different pages). It's here:-

https://www.a7a10.net/forum/doc/parts/BSA_Edited_A7_A10_Spares.pdf

Edit: The Index is on page 6 and the page you want is 29.
Title: Re: 1961 A10GF Tank Mounting
Post by: AWJD on 01.08. 2019 07:30
Very nice! I know parts book 00-5086 is supposed to apply to 1960-62 but how do we know this? Normally, this is determined when a new parts book is issued in a later year but was there one issued for the A10 in 1963 or should we assume 00-5086 applies to 1960-63?
Title: Re: 1961 A10GF Tank Mounting
Post by: RogerSB on 01.08. 2019 10:28
I struggled to find a parts book covering a 1961 A10 model with 1959 being the closest I could get to it.

Hi AWJD, my response was to the statement above, i.e. to cover a 1961 A10 - and hopefully being far easier for you to use than the copies made of BSA's version. I can only presume the 00-5086 parts list was the last to cover the later A7s and A10s because I don't think BSA's management would have spent time and money producing a dedicated hybrid version in 1963 just for a limited number of machines they were phasing out and to be superseded in the same year by their newer models. It's generally known BSA used parts produced for newer models on older ones occasionally (e.g. alternators on 1961-63 A10s). I think it more likely they would have issued service sheets to highlight changes to older models. Only my guess, others may know a little more.
Title: Re: 1961 A10GF Tank Mounting
Post by: RDfella on 01.08. 2019 10:46
That was some work, Roger. These old documents can take hours just to refresh one page.
Title: Re: 1961 A10GF Tank Mounting
Post by: JulianS on 01.08. 2019 10:52
There were certainly 2 versions of the 1960-63 parts book, the later version including some changes up to frame GA7 11101 which started the 1961 model season and the earlier version not including the Triumph type 4 spring clutch.

To cope with modifications to parts and new parts introduced BSA issued unillustrated Parts Service Bulletins to dealers giving details. These were issued in series prefix GA for the twins, GB for B group singles. GC for C15, GD for Bantam, G for all models, N for new parts......... there were a lot of them issued.

So our parts books may not show a complete picture.

Dealers/storemen would use them to ammend their books.

The most famous of these parts bulletins probably being G21 from April 1962 which listed RGS parts and N8 from August 1963 which list late Super Rocket and RGS parts (plus some A50 and A65 parts)

Below are 2 bulletins showing the general layout.
Title: Re: 1961 A10GF Tank Mounting
Post by: RogerSB on 01.08. 2019 11:22
Once again to the rescue Julian  *smiley4*,
Title: Re: 1961 A10GF Tank Mounting
Post by: AWJD on 01.08. 2019 12:05
It sounds as though 00-5086 strictly applies for all models from 1960-63 with some changes over this period reflected in additions to 00-5086 but with others via the Parts Service Bulletins. I assume the basic A10 models (not RGS or Spitfire)  produced in 1963 were largely the same as the in the previous 3 years although I'm curious about when and where alternators were fitted.
Title: Re: 1961 A10GF Tank Mounting
Post by: JulianS on 01.08. 2019 15:27
Alternators were fitted, together with a dynamo on some Police specification bikes from 1956. Not all Police A10s had an alternator fitted, it depended on what the customer specified.

These were fitted in CA10 engines until mid 1960 when the alternator bikes adopted the large journal crank. The engine series then changed to DA10A prefix. less than 400 of these later bikes made and many of these were exported.

Australian Police alternator A10 below. From 1961 catalogue.
Title: Re: 1961 A10GF Tank Mounting
Post by: RogerSB on 01.08. 2019 16:05
Great photo - note the tyres with blackened sidewalls - must have been a former marine.
Title: Re: 1961 A10GF Tank Mounting
Post by: ironhead on 01.08. 2019 23:47
Alternators were fitted, together with a dynamo on some Police specification bikes from 1956. Not all Police A10s had an alternator fitted, it depended on what the customer specified.

These were fitted in CA10 engines until mid 1960 when the alternator bikes adopted the large journal crank. The engine series then changed to DA10A prefix. less than 400 of these later bikes made and many of these were exported.

Australian Police alternator A10 below. From 1961 catalogue.

Thanks for the picture Julian, Its a pitty not more than 400 were made as this model with a later 12v stator & rotor would make the perfect A10.
Title: Re: 1961 A10GF Tank Mounting
Post by: BSA_54A10 on 03.08. 2019 02:37
They are a disaster as the stator is bolted to the outer cover so it is near impossible to get it centered on the rotor so the output pulses something fierce.
Not too much of a problem is the bike was fitted with a car sized battery to smooth things out but a big problem if you are running a std 5Ah motorcycle battery.
Title: Re: 1961 A10GF Tank Mounting
Post by: ironhead on 03.08. 2019 10:57
They are a disaster as the stator is bolted to the outer cover so it is near impossible to get it centered on the rotor so the output pulses something fierce.
Not too much of a problem is the bike was fitted with a car sized battery to smooth things out but a big problem if you are running a std 5Ah motorcycle battery.

Never seen one up close, but is that shiny cover at the front of the primary case just a tin cover? If so wouldn't it be possible to access the rotor/stator from outside on assembly & slip feeler gauges between both to get centred  before tightening the cover fully? Or did they bugger it up so it can't be done .
Title: Re: 1961 A10GF Tank Mounting
Post by: coater87 on 03.08. 2019 15:21
 In the picture there is something mounted to the front fender, it does not look like a rocket and looks much further forward to me.

 Anyone know what that is?

 Lee
Title: Re: 1961 A10GF Tank Mounting
Post by: Greybeard on 03.08. 2019 19:56
In the picture there is something mounted to the front fender, it does not look like a rocket and looks much further forward to me.
Anyone know what that is?
Looks like a small plate. Probably says "I am the law!" Here's Judge Dredds', later Lawmaster model:
Title: Re: 1961 A10GF Tank Mounting
Post by: duTch on 03.08. 2019 22:14

 
Quote
In the picture there is something mounted to the front fender, it does not look like a rocket and looks much further forward to me.

 License/egistration plate
Title: Re: 1961 A10GF Tank Mounting
Post by: BSA_54A10 on 04.08. 2019 08:51
Digging deep into the grey cells I think it was the late 80's when the front number plates on motorcycles were abolished.
Some important persons son would have claimed to made the bike unstable at speed ( which they did ) causing a collision.
We had been advocating to have them removed from as far back as I can remember.
Title: Re: 1961 A10GF Tank Mounting
Post by: duTch on 04.08. 2019 09:10

 
Quote
Digging deep into the grey cells I think it was the late 80's when the front number plates on motorcycles were abolished..

 Is about what I reckon too... Beeza's first rego ran out in '84 and it had them (still have them both,but don't tell anyone)- bought the XT600 in '87/8 and don't think it had a front one, rego'd the Gutzzi in '92 and no front one ever, so was definitely somewhere in between (at least in the sunny state)
Title: Re: 1961 A10GF Tank Mounting
Post by: muskrat on 04.08. 2019 10:06
Getting a bit off topic but I think it was late 70's -early 80's. My new 78 XL500S had one, my new 81 CB750F didn't. I remember you could tale the front and back plate in and get a new iridescence one for the back only.
The fun police had to change all the fixed speed cameras to rear view as loosing too much revenue from bikes.
Cheers