BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: Bess on 19 March, 2017, 10:48:28

Title: A65 - Front wheel spindle
Post by: Bess on 19 March, 2017, 10:48:28
     Does anyone know the differences between the following spindles:

* 1968 part number 37-2057
* 1969-1970 part number 37-1641

I have put together forks, brake etc as per the 1968 TLS but the lug on the fork that fits into the TLS plate only enters partway. My thinking is that changing the spindle is the best option but I don't want to spend the cash if I'm barking up the wrong tree.

Best wishes...
Title: Re: A65 - Front wheel spindle
Post by: JulianS on 19 March, 2017, 11:50:46
Have got 1968 damper rod forks and wheel on my A10 but fitted with the 1969 brake plate. Forks with 6 3/4 inch centres.

Photo shows how much engagement of peg into brake plate I get.

The spindle 37 1641 is the one for 1968. It is a Triumph part for Triumph forks with centres 6 1/2 inches, but listed for the 1968 BSA. takes a 3/4 cycle nut.

My spindle is 7 1/4 long. There is a gap between spindle end and fork clamp as seen in second photo.

The spindle 37 2057 is for the 1969 shuttlevalve forks and measures 7 1/2 inches long. Dont know about the position of the shoulders. takes a 3/4 UNF nut.
Title: Re: A65 - Front wheel spindle
Post by: Bess on 19 March, 2017, 15:49:34
Thanks JulianS,
                         My arrangement is the same as yours, with the lug not fully engaged and a gap.

Image j02 show the gap, image r01 on a A50 which I think is the longer spindle and image t01 I welded additional and turned down to suit.

   It's very likely I will buy and fit the 7 1/2" shaft, however my investigations are throwing up part numbers 37-2057 and 37-3582 are identical. Do you know if this is true?

Best wishes
Title: Re: A65 - Front wheel spindle
Post by: JulianS on 19 March, 2017, 16:45:32
Not sure if identical but they are interchangable according to he BSA master price list from 1970 (first photo).

There are a number of different versions of the shuttlevalve forks  BSA (between models)and Triumph (with different versions with 6 1/2 and 6 3/4 inch centre forks and different length pegs to suit ) all looking similar. The A twins version has apparently got an identifying counter bore on the bottoms and the end caps.  See second photo.
Title: Re: A65 - Front wheel spindle
Post by: Bess on 19 March, 2017, 17:46:36
Okay, that changes things. The A50 has the counterbores the 2 A65's do not.

All three sets of forks have been rebuilt from scratch with new items corresponding to all part numbers from years 1969 to 1970 using the fork sliders with and without counterbores (slider part numbers 97-3641 & 97-3645).

My guess is that the counterbores are added to the fork sliders because they have been built as per the diagram attached. Maybe the fork sliders are the same for other models but with different internals.

I would value your opinion...
Title: Re: A65 - Front wheel spindle
Post by: JulianS on 20 March, 2017, 11:28:43
I have looked at 1969 fork parts for A65, B25, A75 and T120. The complete forks are different for all 4.

The the last 3 have the same part numbers for fork bottoms and end caps and the end caps are not handed, the same for each bottom.

The first 2 have the same fork legs and the last 2 have the same legs but different to the first 2,

They all have different yokes.

They all have the same shuttle valve. They all have the same wheel spindle but the A75 is showing the later part number.

The A65 bottoms are unique as are the end caps which are handed.

All change for 1970 though!! Different part number have not looked at them all but the last 3 all share the same fork bottoms but it looks like they are interchangable with the 1969 ones (Triumph service bulletin 362) , A65 has different parts but same handed end caps. Dont know if they interchange.

I suspect the difference is somewhere in the spindle anchorage at bottom of forks.

It must have been quite interesting managing a BSA dealer parts department.

Have you seen this thread?
Title: Re: A65 - Front wheel spindle
Post by: Bess on 20 March, 2017, 12:15:31
Hi JulianS,
                 Thanks for the reply, interesting findings, lucky I haven't got the issues like the chap in Canada but reading through and looking at the photos I had an epiphany.

I measured the metal between the tube and the spindle clamp. The counterbored slider has a length 0.780" the other has 0.650", the depth of thread is longer for the clamp bolts I expect.

I will be using the sliders I have using allen screws for the high tensile strength, unless I can source  new (that's doubtful). The other issue is that the gap between the clamp and slider is slightly bigger on the non counterbored sliders. Cannot determine the difference with the clamps.

Also now need counterbored clamps to fit the correct sliders on the A50.

I have sourced the correct spindle so the original problem should be solved after I fit it.

Thanks for your input, learnt a little more for the autojumbles.. :)

Title: Re: A65 - Front wheel spindle
Post by: Bess on 30 March, 2017, 20:12:46
Hi Julian,
               Just a quick update.

I fitted a 7 1/2 inch spindle, all is okay albeit the lug is still not fully engaged but the wheel sits centrally between the fork legs now.

 In near the future I will investigate the brake plate position in relation to the drum. I might get some leeway if I shim between the plate and the wheel bearing moving the plate closer to the fork leg. Obviously ensuring the shoe area is bearing fully on the drum.

Thanks again........
Title: Re: A65 - Front wheel spindle
Post by: JulianS on 31 March, 2017, 10:59:30

Thanks for updating.