BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Maddog226 on 01 Dec, 2023, 17:29

Title: B44 EA front wheel offset
Post by: Maddog226 on 01 Dec, 2023, 17:29
Hi All,

can anyone provide the offsets/dimensions for the B44 front wheel using the 7" sls half width drum.  This is the version where a lug on the brake backplate engages with a cast-in recess on the r/h forkleg.  I fear my wheel has been built up with too much offset towards the r/h forkleg.  By eye, I am somehere between 3/8 and 1/2" off the c/l of the bike (plumb dropped from headstock and as you look at it from the front of the bike). 

Any help will be gratefully received.

Mac
Title: Re: B44 EA front wheel offset
Post by: EDDIE SIMPSON on 01 Dec, 2023, 17:53
hi mac
the earlier a7 hub is very similar to the unit 7 inch brake hubs but the wheel offset is not central on the b44 and i believe the a7 is central. the b44 brake plate has a strengthened boss.
i have one here but the rim has a rust patch on a  original rim so was planning to have rebuilt.
the wheelbuilder i ve used before is aware of the difference between offsets for twins and singles
Title: Re: B44 EA front wheel offset
Post by: Maddog226 on 04 Dec, 2023, 15:39
Hi All,

I have had a look in the RR book for B44 offset using the 7" SLS drum and they don't seem to make sense either.  I'm going to have to take some measurements and photos and go back to the chap who rebuilt the wheel in the 1st instance.

Eddie, if you are able to attach a photo with a strategically placed ruler/straight edge, I'd be grateful.

Regards, Mac
Title: Re: B44 EA front wheel offset
Post by: EDDIE SIMPSON on 04 Dec, 2023, 22:32
will do tomorrow
Title: Re: B44 EA front wheel offset
Post by: scifi on 05 Dec, 2023, 10:29
As a rough guide, try pushing the same finger from both hands into the gap between your forks and tyre. they should both touch at the same knuckle joint.   If you have a Spoke Key it is easy enough to move the wheel over a few mm by loosening the right hand spokes by quarter of a turn and tightening the left hand side spokes by quarter of a turn.   Make sure you do all the spokes equally, and you should be a bit nearer central.
Title: Re: B44 EA front wheel offset
Post by: EDDIE SIMPSON on 05 Dec, 2023, 18:41
mac,
i measured 18mm from edge of rim to outside of brake plate. without the brake plate it was 13.8mm from edge of drum to edge of rim. all using a square edge and vernier.
Title: Re: B44 EA front wheel offset
Post by: Maddog226 on 10 Dec, 2023, 17:30
Hi All,

many thanks for all the responses.  I have sent some photos and measurements onto the chap who rebuilt my wheel and he has agreed to adjust it to suit the fork/yoke setup I have (it appears I have a 'wide' set of yokes - the bike is a bit of a bitsa tbh) as he set it up using a standard B44 offset.

Thanks again for all your help.  Mac