I am having a problem with a new dual seat for my 1955 B33 (swinging arm model). The original seat isn't available to compare and it looks like the new rear seat fixings are approx 1" out of position. The mudguard and rear seat support bar are original, but seat doesn't align with the original holes . I have spoken today to Classic Bike Shop and they say that their remaining stock has the same fixing holes and that other customers haven't had any problems with the seats. I could have a bracket made to accept the offset fixings but would prefer a standard fit. Classic Bike have offered to take back the seat but that won't solve the problem if other suppliers have the same pattern item.
Has anyone else had this problem and how was it resolved.
Ronnie
Unfortunately, there are many batches of BSA spares out there where the manufacturer got the dimensions wrong and mounted brackets and holes are in the wrong place. I'm not familiar with the B33 seat mounting but I had what sounds like a similar problem on another new BSA seat. In the end I had to make up a couple of small brackets to move the mounting points back to where they should have been.
You could try R K Leighton for a seat which fits.
http://www.rk-leighton.co.uk/bsa/
Thumper & Julian, thanks both for your advice. I will speak to Leighton's on Monday and if their seat has the correct fixing positions order one from them. The photo on their website looks identical to the new seat already supplied by Classic Bikes. Alternatively I will make or have made, brackets to compensate for the offset holes. The supplier also mentioned A10 when confirming that my B33 dual seat was correct part number. That makes me wonder, is the A10 swinging arm frame identical to my B33 swinging arm frame ? I need one front RH footrest and splined footrest stub and wonder if an A10 part would also fit ?
Frames not quite the same, differences to take twin/single engine but foot rests are.
The nearside parts changed for both for 1958 on.
Andy Leighton knows his stuff and will be able to advise on the ins and outs of the fixings for a B33 seat.
Thanks for the assistance. I have now ordered a replacement dual seat from Andy Leighton.