Author Topic: A7 rigid front end...again  (Read 998 times)

Offline prewarbsa

  • Moving Up
  • **
  • Join Date: Jun 2008
  • Posts: 22
  • Karma: 0
A7 rigid front end...again
« on: 16.10. 2009 12:19 »
Is there anything to stop me putting a '48 B33 front end into my A7 rigid, including the top and bottom yokes? Any horrendous differences in length, girth, width, colour, shape, niceness, etc??

BTW thank you to the folks who suggested a late 60's A65 front end...I'm keeping that one up my sleeve for now!

Offline beezalex

  • North Carolina, USA
  • Valued Contributor
  • ****
  • Join Date: Jan 2008
  • Posts: 374
  • Karma: 4
Re: A7 rigid front end...again
« Reply #1 on: 16.10. 2009 14:53 »
Hmmmm....dunno about '48, but for '49 (I don't think much changed on the front end), the lower yoke and fork sliders are identical...the top yoke and tubes are different part numbers, but I'm guessing they will interchange and I'm quite certain that, as a unit, they will freely swap.

Too many BSA's

Online Brian

  • Wise & Enlightened
  • *
  • Join Date: May 2007
  • Posts: 1708
  • Karma: 41
  • Mt Gambier, South Australia.
Re: A7 rigid front end...again
« Reply #2 on: 17.10. 2009 07:22 »
Pretty sure it will fit straight in. Just a couple of things to keep in mind though, those fork sliders are designed to take the standard 7" front hub so if you want to fit a different wheel it might take some more work. Also the front mudguard mounts are different but if you have a complete front end with wheel and guard none of this matters. If you intend to put a different front wheel in at a later date and are not sure which guard you will use I would try and get a set of 50' or later sliders (as used on the A10) without the hole for the brake plate locating pin. will save some work in the future. The 49' or later sliders that are designed to take the 7" hub can be altered, you simply remove the brazed on casting that locates the brake plate.
Most of this sort of BSA stuff is interchangeable but you just need to be aware of the subtle differences depending on what you intend to do.

Offline LJ.

  • Peterborough UK.
  • Wise & Enlightened
  • *
  • Join Date: Jun 2006
  • Posts: 1403
  • Karma: 15
  • The Red A10!
    • LJ's Website!
Re: A7 rigid front end...again
« Reply #3 on: 17.10. 2009 09:10 »
A set of M20 Girder forks would slot in nicely if you happen to have some kicking around. I know this for certain as my 49 A7 has them. But as Brian says... Most of this BSA stuff is indeed interchangeable! Good Luck.
Ride Safely Lads! LJ.
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline Rocket Racer

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 1434
  • Karma: 16
  • A kiwi with a racing A10 rig and too many projects
    • NZ Classic Sidecar Racing
Re: A7 rigid front end...again
« Reply #4 on: 18.10. 2009 09:28 »
It'll certainly fit, the early XB series ran fuel tank mounted speedo's so the top triple clamp has no holes in it to fit a speedo bracket and the mudguard stays were off a common stub on the back of the slider. Later ZB series have the stubs front and rear and also the speedo mount holes. The 8" and 7" brakes will fit these forks. Later forks do have more advanced damping as standard if you go down the A65 route. There are A65 sliders that still have the LH thread for the QD wheel and also nice damper rod assemblies, much advanced on the X & ZB forks.

my 51 ZB runs the later 8" brake rather than the std pressed 7" brake which is only suitable for a bantam or a shelf.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand