BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Mark B on 04 Jan, 2019, 10:57

Title: Rigid B31 Rear Wheel Spindle
Post by: Mark B on 04 Jan, 2019, 10:57
I've bought a new rear wheel spindle and nuts from Draganfly, and the round internal shoulders of the nuts don't fit into the slots in the frame which the spindle goes through (if I've explained that correctly!). The diameter of the round bit of the nuts is 0.66 inches, and the slots in the frame are 0.60 inches wide.

So, either the newly-made nuts are too large, or the slots in the frame are smaller than they should be.  Can anyone offer any clues? Thanks for any replies.

Mark.  And a happy new year to everyone. 
Title: Re: Rigid B31 Rear Wheel Spindle
Post by: AdrianS on 04 Jan, 2019, 16:07
Have you got the old bits to compare to? Not unknown for new bits to be wrong!
Title: Re: Rigid B31 Rear Wheel Spindle
Post by: Mark B on 04 Jan, 2019, 16:40
If only I had, Adrian! The existing spindle is non-standard, as are the bearings, and there's a dreadful bodge of spacers to get the whole lot to fit the frame. Hence the new spindle.
Title: Re: Rigid B31 Rear Wheel Spindle
Post by: JulianS on 04 Jan, 2019, 16:43
What year is your bike?

The 1946/47 models used a different nut and different rear frame than the later rigids. These parts dont show up in the 1949-53 parts book.

Title: Re: Rigid B31 Rear Wheel Spindle
Post by: sidewaysid on 04 Jan, 2019, 19:11
(https://i.postimg.cc/B66P3hSj/20181130-121251.jpg) (https://postimg.cc/GBWmJxsR)

Is the set up like mine shown here
Title: Re: Rigid B31 Rear Wheel Spindle
Post by: Garyk on 04 Jan, 2019, 20:51
If it is a 1946/47, the attached may help - it is a screenshot from YouTube of some chap's restoration project 1947 model (apologies if any copyright issues!!). It certainly helped me, as mine was a basket case and it took a bit of sorting to get it right. As you suggest, the nut shoulder should fit into the slot on the frame - this is all that is outside the frame. Inside the frame is a snail adjuster that locates on a small lug inside the frame. Only thing to note is the tapered bearing obviously sits inside its cup, located in the hub.

I've just measured the slot in my frame with a digital Vernier caliper - came out at 0.62 inches, similar to yours. I tried it with the calipers at 0.66 inches, wouldn't fit anywhere near. Hence, I think you're right, the new nuts are too large. If Draganfly can't come up with a solution, I've found Simon at Barleycorn Engineering is very helpful and everything I've got from him has fitted perfectly - although I don't know if this nut is an item he stocks.

Hope the above makes sense and is of some help!
Title: Re: Rigid B31 Rear Wheel Spindle
Post by: sidewaysid on 05 Jan, 2019, 08:27
The nuts and thick washers for my build were amazingly found on ebay, I think it may have been listed under BSA C11 or C12, they are stainless, and didn't cost much if I remember.
Title: Re: Rigid B31 Rear Wheel Spindle
Post by: Mark B on 06 Jan, 2019, 14:31
Thanks for the replies. The bike was first registered in 1955, so it must have been an outdated rigid sitting in a dealership while everyone bought the new-fangled plunger and swinging arm models.  Sideways Sid: the spindle and fittings look exactly the same as yours.  I also found that the new bearings wouldn't fit the spindle so the whole lot's back with Draganfly for further investigation.  Mark.