Top Yoke and Forks Fused!

[duTch]

Which reminds me, how you going with it Jesse, haven't heard update for a while?? If you're still battling, try using a drift (~lump of flat bar~ 25 x10 mm?), and hit hard up against the underside of top yoke with a big hammer, or similar, on top of nut as resistance. This may require 2 people and a combination of some or all other options?
     Another thought is, and I think someone else pointed out that if the bottom yoke 'pinch' is loose enough(?) to slide down and off the bottom, try that.....uhoh yeah remembered is the slider/springs/stuff still on, or can you dismember (dismantle)it??

   cheerrs

[Jes-can]

Sorry I've away for the weekend so haven't touched the bike in a few days. Right side is still stuck, so will try some of these suggestions when I'm back. I'm thinking heat is the next on the list. I'm sure it will come out eventually. Looking forward to having it all apart so I can start restoring it!

On another note. I've got the top end of the engine off and the pistons have quite a lot of scoring on the top and one of them has a small scuff on the top surface. Should I replace them? And I have seen a few sets on Ebay.

http://www.ebay.ca:80/itm/ws/eBayISAPI.dll?ViewItem&item=300710979100&ssPageName=ADME:B:WNAFP:CA:1123

Thoughts? The engine was running ok before I started taking it apart, but if it's apart I might as well do as much as I can so I don't have to do this again for a while.

[RichardL]

A photo of the pistons would be useful. Worst case, I think, might be that the "scuff" was a hot spot that just reached melting point and subsided, but hard to know without seeing. Even on seeing, others here will be better at the diagnosis than myself.

Richard L.

[Jes-can]

Bloody thing is still stuck! I've tried torching it to heat it up and knock it out, but no luck. I have now resided myself to the fact that the fork is buggered so I've started to drill holes through below the top yoke to see if I can force it out from the bottom, but so far it hasn't budged! I'll get it out eventually but wow! Anyone know a good source for replacement forks?

[Brian]

Jesse if you are at the point of being prepared to damage the fork leg then try this.

Firstly wedge a screwdriver or similar in the bottom yoke, then unscrew the top nut about two turns.

Now the good bit, get a hammer and hit it. Now I dont mean a little hammer and when I say hit it I mean give it a good clobber. This will mark the top of the nut so use an old one if you have one.

The top of the fork is tapered, you only need to break the hold on the taper and it will come free. It only has to move a couple of thou to let go.

I've dismantled hundred of BSA forks over the years and have never found one that wouldnt come out.

The trick is to use a heavy hammer and give it a good hit, soft hammers and little taps will not work.

[RichardL]

Brian,

Your post sent me to the garage to look again at the structure of the top yoke. It is not thick and it seems that enough of a whack could fracture or bend it. Maybe I'm dead wrong. Jes' stanchion sounds like it is uniquely frozen to the yoke by rust or corrosion. I suppose that if the thing is going to get destroyed in the process anyway, maybe the huge hammer hit is worth a try, but is there not also a risk of messing up the steering-head bearing races? The stanchions are easier to replace than the yoke, so maybe the route could be to to cut off the stanchion below the yoke and then saw through its remains a couple of times until it gives up.

Richard L.

[Jes-can]

Yes I've already started drilling through it and it still hasn't budged. I'll continue on this route and see how it goes. It's obviously completely corroded where they meet. The bike is in relatively good shape, but I don't think it's been completely pulled apart like this. At least not in a long time. All the other stuff now seems easy in comparison to this issue which really should be simple. It's been fun though and I'm not in a rush to get it done, so I'm not too annoyed by it. I'll keep trying and keep you posted on progress!

Thanks for all the advice so far.

[RichardL]

Jes,

Looking back at your posts, we didn't hear much about you other than "stuck forks". Without prying, would you mind sharing where you are located?

Richard L.

[Brian]

My method does sound brutal doesnt it Richard, but it will work. I have had to resort to it a couple of times over the years. It wont bend or damage anything.

Its a case of sending enough of a shock through the metal to make the taper let go. A bit like one of those hand held impact drivers, you can use a soft hammer or a small hammer and they just will not work, they need a good belt with a heavy hammer to work properly.

Another example would be tie rod ends in cars, you can bash away at them all day with a copper hammer and they will not come apart. Hold a metal dolly on one side and give the other side a good belt with a heavy hammer and they will come apart every time.

"If at  first you dont succeed, get a bigger hammer" 

[muskrat]

 G'day all, how about removing the steering spindle/bottom yoke from the top yoke/stuck leg. Then set it up in a press and use the old nut (it should look pretty second hand by now).
 A nice new set of hard chromed legs arn't that expensive.
Cheers

[Topdad]

Hi Jes, Brian and Richard re my prev post I'm with Brian on this ,always found a 4lb lump hammer worked wonders and didn't do any lasting damage.  I to have never had a set of forks that wouldn't budge but there's always a first. Glad to hear that it's not but you off Jes ,these things are sent to try us and It must get better after you have sorted this! you've more patience than me though by now i'd have ground through the top yoke and started looking for a new one on e-bay or anywhere and has Richard has said probably regreting it has the fork is probably donald ducked anyway .best wishes BobH

[RichardL]

Jes,

I just realized that those of us who have been on here for some time have come to know eachother's experience and recognize it without words, but newer members don't have that advantage. I just want to say that the likes of me (a one-bike rebuilder of a basket case) know that the experience of Brian and others with multiple (or many) bikes deserves high respect. My thanks to Brian for a variety of good advice that's helped me. Paranoia strikes deep, but if Brian says "no harm", he probably knows what he is talking about.

Richard L.

[Jes-can]

Just realized I posted a response in another thread by accident! Anyway. Now having trouble getting the clutch centre nut off! And is there a special tool for removing the other one on the crank the holds the large spring in place?

Cheers.

[Stephen Foster]

Im in agreement with "mannosound" ..there are times Id have been floundering without "Brian"s advice & Id like to take the opportunity to thank Him !!

Regards,
Steve ..

[duTch]

Hi Jesse, I think I noted that you'd jumped another thread to announce success, is that correct??
  Re the clutch nut that's been discussed recently too...somewhere- you'll have to search?
 Re the Hammers, when I mentioned awhile back 'rubber mallet', I think I had in mind genteel things like shafts and like with threads on, and tinware, as I personally have a dangerous propensity for big hammers, a 10 pounder of which can work wonders if used carefully. Bloke I worked for a while back had a 14lb'er- that was fun!! requires good aim.

cheers