Looking at the parts manual the leading rear brake shoe (item 32) is facing to the rear of the bike but looking in the service manual the leading shoe is facing to the front!
Which is the right way the parts manual or sevice manual or does it make a difference if the brake lever (item 24) is facing up or down?
Also, in this picture take from R.B.'s book it shows a spacer between the brake plate and swing arm,
none shown in parts manual of the 1971 BSA (or Triumph) any thoughts? I have assembled mine as per the parts maunual and the wheel is dead central in swing arm without this 'additional' pictured spacer, but once I'm not sure about something I start to doubt everything!
They reused the illustration from the Fury parts book, so thats why the shoes are the wrong way round. Late bikes used a longer lever and was fitted upwards to clear the wheel spindle.It should fit only one way to be at the correct angle.
Nice one, have measured the difference as you've got me worried, the gap is 5.18mm more on the chain side.
As Gavin's post has now been deleted, could someone confirm that I've got the shoes ass-about-face? The leading shoe marked with an 'L' should be toward the front of the bike and the shoe marked with the 'T' should be to the rear? (Opposite to what is shown in the parts book, as printed in my first post).
I also have in my box of goodies the short down facing lever and the longer up facing lever which should I use?
I'm not sure if this applies to A65s or not but when I started on my T150 I didn't have any wheels, or much of anything else for that matter so when started piecing together the rear hub and axles, spacers and what not I looked at a lot of photos in the TOL gallery. It seems the 71 models used the short offset lever turned downward and 72 on up used the longer straight lever turned upward. 71 R3's also used the shorter offset lever turned downward.
When given the choice between two evils I picked the one I haven't tried before
You will notice that in the parts book the brake plate and shoes are shown on the opposite side of the drum for clarity. The parts book is meant to aid in ordering parts, it is not a map for how things go together. From the '71 workshop manual, "The shoes are interchangeable, and are fitted with loose abutment pads to prevent wear on the pivot block." I've never seen a pair which were marked, L and T. I guess if you have clearance you would wish to use the longer lever for increased leverage. My '71 has the shorter lever pointed down and no spacer between the plate and swing arm. Works about as well as any comical rear brake I've ever had.
It mentions (in the front wheel section)that the brake shoes are interchangeable. It also mentions steel abutments between the shoes and the pivot. The front wheel doesn't have a pivot and/or steel abutments and the shoes ARE interchangeable.
However the rear wheel shoes are NOT interchangeable. It doesn't say so (in the rear wheel section) of the book either. The steel abutment plates are at the bottom of the shoes and only fit the bottom. The abutment-plates canot be fitted to the top. Therefore it is not possible to interchange the shoes. This is probably the treason that the shoes are marked L & T.
Upon further investigation the rear wheel shoes ARE interchangeable. From moving the left shoe to the right. This however results in the leading edge becoming the trailing edge. So they are not really interchangeable without upsetting the works.
Dick, therefore in the photo I sent you the shoes are clearly the wrong way around. This is however the way they were when I bought the bike. And I put them back the same way. By the way the brake worked fine, but maybe it works better now!
I have now swapped the shoes around, which results in the leading edge being similar to the picture in the 71 works manual, seeing that this is the consensus on this thread. Luckily the wheel is still out of the bike, took 10 minutes to change.
Now the lettering is not visible when the shoes are installed, however the L is on the right, towards the front of the bike.
Thanks for starting this thread, without which I would have installed the shoes wrong way around.
Yes I am waffling on a bit! However for peace of mind:
There is a very nice explanation on the workings of the leading edge drumbrake on www.engineeringinspiration.co.uk/drumbrake which confirms that the Leading Shoe marked L should be installed towards the front of the bike.
Looking at the drawing in the parts book, the drawing is correct, except that the leading and trailing shoes are transposed, also as far as the part-numbers are concerned.
You will notice that in the parts book the brake plate and shoes are shown on the opposite side of the drum for clarity. The parts book is meant to aid in ordering parts, it is not a map for how things go together. From the '71 workshop manual, "The shoes are interchangeable, and are fitted with loose abutment pads to prevent wear on the pivot block."
I've never seen a pair which were marked, L and T.
I guess if you have clearance you would wish to use the longer lever for increased leverage. My '71 has the shorter lever pointed down and no spacer between the plate and swing arm. Works about as well as any comical rear brake I've ever had.