BSA B50 -500 APG Build

[Old Scrambler]

Great Build and congrats on the 117.9 run......Hope to see you at BUB

[Koncretekid]

What I've learned!

I mentioned I had a few issues at Loring.  I'd like to share them with you to try to prevent a repeat of my mistakes by others.

Vibration is my biggest enemy!  The first photo is the oil filter after I added hose clamp and lock wiring.  I knew that!  The second photo is the rear fender showing the broken tab.  The third photo is the re-attachment, showing welding on both sides of the tab.  I also added a new mounting bracket to catch the top of the fender with 2 more bolts.

Not shown is another bracket to mount the chain guard. Mine is made of 1-1/4" by 1/8" steel and is heavy.  One bolt was missing after five runs, and it was cracked in two places.  I will also use self-locking steel nuts.  The idler shaft is not shown, but I had problems with this, as well.  The included bearing in the idler sprocket, which was purchased thru Princess Auto, did not have a locking collar and had a cheap ball bearing.  The vibration loosened all three set screws which was repaired by spotting the shaft with a drill bit, and putting in the set screws with lock-tite.  I am going to make a new collar for the bearing (which will be of better quality) with a set screw.  I think the bearing just spun on the shaft so developed a wobble.

[coloradodave]

Those big thumpers do vibrate a bit don't they?

[wobblywalrus]

My BSA's had the same problem.  A strong mounting plate attaching the frame and the cylinder head helped. and dynamic balancing, too. 

[Koncretekid]

Wobbly,
Mounting plates seem substantial - - 1/4" T6061 plates attached with grade 8 bolts plus a head steady made form 1/4" x1" steel, all attached to 1/8" wall mechanical tube crossmembers.  Balancing - -nada!  Maybe next year I can find someone to do that.  In the meantime, the entire frame becomes the harmonic balancer.
Tom

[wobblywalrus]

Tom, a thought.  I have not tried this.  Engine vibration is dampened by increasing the mass the vibrating parts must move.  Perhaps some really thick steel mounting plates, say 0.5 inches, between the engine and frame, all tightly bolted to the engine, would give the motor more mass.  Plus, the extra weight of the plates would be ballast, too.

[vgabndo]

Hey Koncrete, congratulations on getting a time you wanted. I'm curious. I only ran once at Bonneville and in 1969 with a stock engine modified frame 250 cc we went 117.252. (on a 107 record) The fastest leg was 121.621.  That was a 1967 engine.  What am I missing that you're  happy with your 117 with twice the displacement?  Respectfully askin'

[Nortonist 592]

What were you riding?  121 out of a 250 cc pushrod single is fairly movin'.

[Stan Back]

Well, Bill, I was with you until I looked at the record book.  And you know how much I know about 'cycles.  But the P/P record is 136 and change.  Don't have to be a single, tho.

Stan (the old 65 mph Parilla owner) Back

[Nortonist 592]

I know Stan.  That's Dave's record.  He's a limey too!   My remark was an attempt at sarcasm.  This build thread is about extracting as much as possible from an elderly (you should know about elderly) British single.  If it wasn't we'd all just run out and buy Hayabusas.

[Stan Back]

Ya, if our credit ratings were better than I think they are.

[Nortonist 592]

If we could go as fast as our credit rating we'd be doing good.

[coloradodave]

Credit ratings may not mean as much now as they did a few years ago, I think I would rather just have the cash thank you very much.
Leaving in 5 days, can't wait
 

[Nortonist 592]

Hope to see you there.

[Koncretekid]

Hey Koncrete, congratulations on getting a time you wanted. I'm curious. I only ran once at Bonneville and in 1969 with a stock engine modified frame 250 cc we went 117.252. (on a 107 record) The fastest leg was 121.621.  That was a 1967 engine.  What am I missing that you're  happy with your 117 with twice the displacement?  Respectfully askin'

Hey vgabndo, what were you riding?  The pushrod 250cc records are under 90 mph, and the pushrod 500cc records are from 112mph - 115mph currently. Still, Bonneville is more of a challenge than Loring because of the salt, the altitude, and the mile long run required for record, plus a return run. I will need everything and then some to get a record.
Tom