The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: cosmikdebriis on 15.03. 2012 08:13

Title: Plunger head races removal from frame ?
Post by: cosmikdebriis on 15.03. 2012 08:13
Regards the steering head races on a plunger framed A10...

There doesn't appear to be an easy way to drift these out but there is an internal thread for a "special tool".

As I'm too tight to buy one I just wondered if anyone knew of an alternative?

Looks like the bottom bracket from a push bike might screw in?

Update...

Just tried a cup from a bicycle bottom bracket and it's too small... Grrrr...
Title: Re: Plunger head races removal from frame ?
Post by: terryk on 17.03. 2012 05:42
Weld a piece of rod across them then hit them out from the other side.
Title: Re: Plunger head races removal from frame ?
Post by: terryk on 17.03. 2012 05:44
Of course you will need to buy new or good SH ones. It may be a good time buy the tapered type.
Title: Re: Plunger head races removal from frame ?
Post by: BSA_54A10 on 17.03. 2012 09:52
Get a long cold chisel 10" or better.
Grind a corner out of one ( or both if you feel like it ) side.
This will now go inside the steering tube, locate on the thin edge of the bearing cup so you can tap them out.
The easiest method is to run a heavy line of electric weld around the cup.
When cool it will fall out.
Title: Re: Plunger head races removal from frame ?
Post by: cosmikdebriis on 17.03. 2012 11:31
Thanks guys though what I actually did was...

Don't read on if you're a little squeamish or a rivet counter... *eek*

Drilled two small holes in the frame (one for top and one for bottom race) that allowed me to use a punch to push the races out. To explain more fully. for the bottom race, I drilled a hole in a similar manner as the grease nipple but so that it came through at the bearing seat instead of above it.

Lost a couple of drill bits in the process as they obviously went blunt when they reached the bearing.

I'll now tap a thread and insert a grub screw so that, in future, it can be done again ;)

I did consider the structural integrity of the whole thing but very much doubt there will be any problems.

Pity BSA didn't do this in the first place ;)

Title: Re: Plunger head races removal from frame ?
Post by: bsa-bill on 17.03. 2012 14:45
Quote
Pity BSA didn't do this in the first place

Yes what on earth were they thinking of, not making the replacement of head bearing easy some sixty years later *whistle*
Title: Re: Plunger head races removal from frame ?
Post by: fido on 17.03. 2012 18:12


Lost a couple of drill bits in the process as they obviously went blunt when they reached the bearing.

Quote
Drill bits can be sharpened  ;)
Title: Re: Plunger head races removal from frame ?
Post by: muskrat on 17.03. 2012 19:12
 I've used both of Trevor's methods on many bikes over the years and Terry's once.
Did you replace with std or tapered roller?
Cheers
Title: Re: Plunger head races removal from frame ?
Post by: cosmikdebriis on 17.03. 2012 22:55
Bit of an admission going on here as this is not a restoration, more of a mild customisation.

I'm fitting front end from a Chinese import bike with upside down forks  *eek* *eek* *eek* *eek* *eek* *eek* *eek* *eek* *eek* *eek* *eek*

I'm making a kind of flat tracker.

I'm keeping all the original bits and with the exception of the two tiny holes I don't intend to modify anything that can't be put back to standard.

Just fancied something a little different.
Title: Re: Plunger head races removal from frame ?
Post by: SixFingerJack on 18.03. 2012 08:11
Bit of an admission going on here as this is not a restoration, more of a mild customisation.

I'm fitting front end from a Chinese import bike with upside down forks  *eek* *eek* *eek* *eek* *eek* *eek* *eek* *eek* *eek* *eek* *eek*

I'm making a kind of flat tracker.

I'm keeping all the original bits and with the exception of the two tiny holes I don't intend to modify anything that can't be put back to standard.

Just fancied something a little different.

How very very dare you?
You'll have the rivet counters after you now!
I think I may be getting told off too, when they see what I'm doing to my A7.....
(http://img535.imageshack.us/img535/8003/dsc0070si.jpg)

Good on ya mate, different is good.
Title: Re: Plunger head races removal from frame ?
Post by: bsa-bill on 18.03. 2012 10:09
Shame on you both, may the god of all things A send a plague on both your houses. *evil* *evil* *evil*
and when you've finished the Devils work each of you suck six lemons, this won't atone for your sins but will take the smile of your faces *smiley4*

Joking of course - best of luck with the projects
Title: Re: Plunger head races removal from frame ?
Post by: cosmikdebriis on 18.03. 2012 11:05
Liking the springers and the 16" wheels *beer*

Mine is more of a "Scrap Heap Challenge" effort. *smile*

I'm sorting the engine, new shells, rings, bushes/bearings etc but I want it to have that "ugliness" about it. Frankly because I own a lit of vintage bikes, right back to 1920 and I just wanted a break from nut and bolt restoration.

It's bliss...
Title: Re: Plunger head races removal from frame ?
Post by: SixFingerJack on 18.03. 2012 17:06
Thanks, still got a long way to go, I've built a few bikes in the past, this is first time I've used something really old as a donor bike.
Not sure how much of the original I'm gonna use, that's just a quick throw-together to see how it sits with the springers and 16 rims.
Sometimes you have an idea in your head of how it's gonna look, but when you see it in metal it looks nowt like, this turned out ok!