Author Topic: Top Yoke and Forks Fused!  (Read 3447 times)

Offline Jes-can

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Top Yoke and Forks Fused!
« on: 11.06. 2012 16:49 »
Hi New member here. I did some searching last night before joining the forum, but couldn't find any posts about this.

I have a 1957 A7 which I am restoring. Most of the bike has come apart quite easily, but I started pulling the front end apart last night and when I got to removing the forks i discovered that they appear to be fused to the top yoke. I have the Hanes manual and followed all the steps. Not sure what to do at this point to get them out. Any suggestions would be greatly appreciated. The alternative if they are completely stuck would be to grind the top yoke off and replace the front assembly, but after looking on Ebay, it doesn't seem like these parts are in abundance.

The rest of the bike is in decent shape, but I guess if the forks have not had any attention recently I could see how this would happen.

Thanks in advance for your response.

Jesse

Offline fido

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Re: Top Yoke and Forks Fused!
« Reply #1 on: 11.06. 2012 17:11 »
Try soaking the area with penetrating fluid and leaving it for a few days. As you will appreciate, the forks are held in the top yoke by a taper so they are tighter than equivalent Japanese forks but they don't usually give much of a struggle to come apart. I don't know what the manual says but when I do them I loosen them at the bottom yoke, loosen the top nuts (bolts?) a few turns, hold a block of wood on the top of a nut and give it a tap with a lump hammer.

Offline Goldy

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Re: Top Yoke and Forks Fused!
« Reply #2 on: 11.06. 2012 17:53 »
As fido says they can be tight on the taper.Make sure the bottom yoke is free by knocking a wedge into the clamp slot. For the top I use an old fork top nut which I drilled and fitted a 1/2 inch bolt and it gives me something to get a decent strike at with the hammer. Try warming the top yoke to expand it a bit. All the best with it.
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Online Greybeard

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Re: Top Yoke and Forks Fused!
« Reply #3 on: 11.06. 2012 17:56 »
This link shows the official fork strip down

http://www.bsawiki.com/index.php?title=Chapter11

Offline Jes-can

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Re: Top Yoke and Forks Fused!
« Reply #4 on: 11.06. 2012 20:48 »
Thank you for the replies. Put the but back in and giving that a few taps sounds like it makes the most sense. I'll give that a go and let you know how I make out.

Cheers,
Jesse

Online duTch

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Re: Top Yoke and Forks Fused!
« Reply #5 on: 12.06. 2012 00:44 »
Quote
Put the but back in and givi.....

Not quite sure what that means??

 Hiya Jesse, It may be worth putting the angle grinder on ebay- get rid of the temptation! *smiley4*
 
 Also maybe worth backing off the stem adjuster a touch to allow the bottom yoke to move a tad, in case the bottoms are also tight??

 Also something (like a lump hammer or heavier, or piece of wood/pipe from the floor up) under the top yoke(next to where you're banging on top) will help not bend it, and sometimes a rap on the side of the taper helps.

 Good luck, duTch
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
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Offline Jes-can

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Re: Top Yoke and Forks Fused!
« Reply #6 on: 12.06. 2012 01:17 »
Sorry hasty typing! Sorry I meant the top nut!

I'll try all these suggestions tonight and see how it goes.

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Re: Top Yoke and Forks Fused!
« Reply #7 on: 12.06. 2012 08:50 »
 G'day Jesse, welcome to the forum.
                                                 Dutch has a point as I have had them that tight in the taper that a good belt may have bent the yoke. Buy yourself a nice new pair of nuts (mine are worn out too  *eek*) so you can give the old ones a good flogging. Screw'em in nearly all the way and hit with a hide mallet, Work your way up the knockometer range till it gives. WHAT, you only have one hammer. LOL.
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Offline Topdad

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Re: Top Yoke and Forks Fused!
« Reply #8 on: 12.06. 2012 10:49 »
Hi Jesse, and welcome. All of the above are how I've just stripped my forks down on Sunday and will work. Musky's idea to buy new nuts can sort out another question before you ask it ,how to get them fitted again particularly if you have any sort of headlight cowl on the bike. Well no need for fancy special tools ,use one old nut has advised has the dismantler (keep for future use ) and the other cut/grind the edges so that it fits through the tapered hole ,drill an hole through centre ,buy a length of threaded stud from an hardware shop ,one nut above 2 below , screw into fork leg push the threaded stud up through yokes/cowl and a large socket which you p[lace on the top yoke ,a few washers on top of the socket run down another nut ,pull into taper and pull up fork leg  with a spanner on the nut bingo tightnen bottom yoke pinchbolt , remove "customised tool" ,insert bright and shinny new one bingo jobs agood 'en !! took much longer to write than do ,I promise. Sorry yours is proving awkward but normally it's one of the easier jobs and I'm positive that with a bit of "persuasion" ie big hammer you'll get it done, best wishes BobH.   
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Re: Top Yoke and Forks Fused!
« Reply #9 on: 12.06. 2012 11:05 »
Hye Topdad, I'm sure that'll work.......after a couple of reads,.... and, musky reckons I did too much keepin' the battery topped up???...uh..you had to be there..

Cheers,
          duTch
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
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Offline Jules

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Re: Top Yoke and Forks Fused!
« Reply #10 on: 12.06. 2012 11:36 »
I have always found that a (good!) tap onto the loosened nuts breaks the taper ok, however, I'm interested in Top dads assy. process and whether others have found it necessary to actually use a special tool for reassembling into the taper. I had assumed that just tightening the nuts on the top would pull the taper in and lock up the top into the yoke adequately, is that not true?? cheers

Offline Topdad

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Re: Top Yoke and Forks Fused!
« Reply #11 on: 12.06. 2012 12:17 »
absolutely right 'cept those canny BSA engineers went and covered the fork legs at the top with a cowl /shroud or headlight ears which those pesky legs have to go through  and sods law dictates that has you push the fork leg upwards so it'll slip back into it's retracted position , bloody infuriating so I've found my method stops hammers and bit's of bike being thrown threw the shed wall ,oh you can use a wooden broom handle too ,through yokes twist into threads and pull gently upwards  but it comes unstuck sometimes and anyway the wife usually wants it back normally just when you need to work on the but always  a standby. By the way it costs about £3 from hardware shops  and you get some extra studding which is always useful,hope this is of help, best wishes BobH
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Re: Top Yoke and Forks Fused!
« Reply #12 on: 12.06. 2012 12:19 »

.. no need for fancy special tools ,use one old nut has advised has the dismantler (keep for future use ) and the other cut/grind the edges so that it fits through the tapered hole ,drill an hole through centre ,buy a length of threaded stud from an hardware shop ,one nut above 2 below , screw into fork leg push the threaded stud up through yokes/cowl and a large socket which you p[lace on the top yoke ,a few washers on top of the socket run down another nut ,pull into taper and pull up fork leg  with a spanner on the nut bingo tightnen bottom yoke pinchbolt , remove "customised tool" ,insert bright and shinny new one bingo jobs agood 'en!!

Briliant idea thanks. I'm doing my forks as well. I've bought new top nuts so I will use the old ones as suggested.

Neil Ives

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Re: Top Yoke and Forks Fused!
« Reply #13 on: 12.06. 2012 12:47 »
Heya Jules,
          And Topdad too,Bad connection here, Yes as Topdad says it works in some cases like mine,  as I have grafted on a  Lightning/Conical front end, and have just looked at the exp.view of the '57 and remember why,as I had this issue with my 'rocket in da '70s ...*problem* *dunno*!!
  Topdads idea is probably good, but in my case not applicable so got a mental block sorry!!
 cheers dutch
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline fido

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Re: Top Yoke and Forks Fused!
« Reply #14 on: 12.06. 2012 12:56 »
.....no need for fancy special tools ,use one old nut has advised has the dismantler (keep for future use ) and the other cut/grind the edges so that it fits through the tapered hole ,drill an hole through centre ,buy a length of threaded stud from an hardware shop ,one nut above 2 below , screw into fork leg push the threaded stud up through yokes/cowl and a large socket which you p[lace on the top yoke ,a few washers on top of the socket run down another nut ,pull into taper and pull up fork leg  with a spanner on the nut.....   

I think some bikes had a damper rod attached to the top nut as I found one at an autojumble that already had a tapped hole in the threaded part. I cut the hexagon part off and use it with an old stud in a similar way to your suggestion. I don't bother with the socket, washers etc though. When the fork is through high enough to catch the threads with the proper fork nut I just tighten the bottom yoke pinch bolt slightly to stop it falling back down.