Author Topic: A10 S/A forks  (Read 322 times)

0 Members and 1 Guest are viewing this topic.

RESTORER

  • Blue Star
  • **
  • Posts: 69
    • View Profile
A10 S/A forks
« on: 14 September, 2020, 09:36:55 »
Hi all, hope you are all well.  I have a 1954 Flash restoration now finished, or so I thought.  If I hold the front wheel, I can move the handlebars and by some distance. This is not a rattle, more like about 10 degrees. I have now stripped and rebuilt these forks three times and cannot sort it. The bushes, shims, fork shafts, seals and seal holders are new and I have tightened the parts in the order given, really tightened.  They have oil in and I have pumped them a few times to tighten the bottom clamp. Before I try oversized bushes, which is the only thing I can think of but can't believe I would have this much play, can anyone think of anything else I can try? Thanks for reading.
1954 A10 Golden Flash, Swinging Arm

craigc11g

  • Blue Star
  • **
  • Posts: 91
    • View Profile
Re: A10 S/A forks
« Reply #1 on: 14 September, 2020, 11:11:51 »
front guard lose missing or split , it acts as a brace , wheel bearings worn out , yokes lose

Bess

  • Golden Flash
  • *****
  • Posts: 1067
    • View Profile
Re: A10 S/A forks
« Reply #2 on: 14 September, 2020, 12:31:49 »
Hi,
     Steering stem pinch bolt tight?

Best wishes...

RESTORER

  • Blue Star
  • **
  • Posts: 69
    • View Profile
Re: A10 S/A forks
« Reply #3 on: 14 September, 2020, 13:41:13 »
Thanks lads, all is tight and the wheel bearings are new. The wheels are rebuilt chrome rims with SS spokes by CWC.
1954 A10 Golden Flash, Swinging Arm

craigc11g

  • Blue Star
  • **
  • Posts: 91
    • View Profile
Re: A10 S/A forks
« Reply #4 on: 14 September, 2020, 15:08:25 »
i can only think front guard is flexing , is it the standard guard

idie

  • Silver Star
  • ****
  • Posts: 288
    • View Profile
Re: A10 S/A forks
« Reply #5 on: 14 September, 2020, 18:40:02 »
You will always get some form of twisting on the BSA forks. As said check that every thing is tight especially where the top yoke clamps to the steering stem, if that isn't tight the sleeve  that adjusts the bearings will wind up and down the steering stem.

RESTORER

  • Blue Star
  • **
  • Posts: 69
    • View Profile
Re: A10 S/A forks
« Reply #6 on: 14 September, 2020, 20:44:15 »
Hi and again thanks.  The mudguard is not the original, I bought it at an auto-jumble. It was new but I do not know its maker, see pic for the style.  The brackets fit OK except that the rear one needed a new hole in the mudguard about 3/8" towards the rear.
Having done more checks today, the upper assembly seems rock solid with no movement at all in either yoke, including the stem clamp. However the movement seems to be most obvious about the centre of each leg. It is difficult for one person to judge the movement whilst at the same time turning the bars and holding the wheel still, but in relation to the mudguard, what happens is that as the bars are turned one fork goes forward and the other goes backward as you normally expect when turning, but when considering that the lower half of the leg and also the wheel and mudguard are held still, this should not happen. Surely the offside should be locked by the brake strap and also by the spindle clamping it against the fork leg, and the nearside by the spindle clamp under the other fork leg, yet the handlebars still turn.  That's where I'm at, not really knowing what to try next except maybe get the tubes inspected and some oversized bushes made. Has anyone had this done and is able to recommend the firm?  Preferably in the North West but not essential. Sorry this is a bit long, but if you are still awake, all comments would be really appreciated.
1954 A10 Golden Flash, Swinging Arm

EDDIE SIMPSON

  • Royal Star
  • ***
  • Posts: 127
    • View Profile
Re: A10 S/A forks
« Reply #7 on: 14 September, 2020, 20:57:40 »
the flex at the wheel and fork bottom is usually taken up by the mudguard arched bracket acting as a brace. or your wheel and fork clamping is wrong.

EDDIE SIMPSON

  • Royal Star
  • ***
  • Posts: 127
    • View Profile
Re: A10 S/A forks
« Reply #8 on: 14 September, 2020, 21:10:48 »
once i had a wheel spindle bottom out at the thread leaving some play on the wheel on the clamp fork side. i had to cut a bit of hollow pipe to lengthen the step in the spindle so it clamped the wheel.

JulianS

  • Empire Star
  • *****
  • Posts: 2037
  • A10
    • View Profile
Re: A10 S/A forks
« Reply #9 on: 14 September, 2020, 21:26:23 »
Are all the fixing bolts the correct size? Any undersize will reduce clamping force.

RESTORER

  • Blue Star
  • **
  • Posts: 69
    • View Profile
Re: A10 S/A forks
« Reply #10 on: 15 September, 2020, 20:57:01 »
I believe that all the bolts are the correct size but if needs be later possibly some can be increased, as they are tapped into the base of the fork leg and then fitted with a locknut.  The four round head bolts that hold the mudguard to the brackets are only 1/4" but look to be the originals so should be OK.  I had not considered the spindle thread bottoming out on the first step and the fork leg rather than the second step clamping the spindle sleeve to the brake cover plate, which I think is supposed to happen but I do notice that the new spindle has more thread protruding from the fork leg than the original had, but can that relied upon (see pic). I also attach a view of Draganfly Plate 16 to show my hub assembly. All in all the right thing to do here is remove the complete front end, yokes included, and rebuild. So many thanks for your input, its much appreciated. Cheers.
1954 A10 Golden Flash, Swinging Arm

EDDIE SIMPSON

  • Royal Star
  • ***
  • Posts: 127
    • View Profile
Re: A10 S/A forks
« Reply #11 on: 15 September, 2020, 23:13:11 »
before you strip the front end place a large screwdriver between the brake plate and fork and wiggle around. the wheel should be rigid against the fork. the spindle should also be rigid and the clamp fork stays in place when tightened. there are lots of spindles that look the same but dont work on a a10. the a65 spindle being one.

DAVE BRADY

  • Golden Flash
  • *****
  • Posts: 833
    • View Profile
Re: A10 S/A forks
« Reply #12 on: 16 September, 2020, 08:05:06 »
Good morning,

As all the mudguard stays are attached to the sliders they will have only a small affect on the flexing of the forks and I believe that there will ways be a very small amount of movement which can most certainly be attributed to one part of the forks having to slide on  another.  If the original spindle is still usable try fitting that and see if it makes a difference so eliminating the spindle as the problem.  Does the movement feel springy in that it corrects by itself or do you have to twist it back in to place?  If springy then it is likely to be the 'natural' flex in the forks.  If not and the spindle has been eliminated then it may be worth revisiting the yolks and the fit of the sliders in them.  Are the top tapers correct and does the bottom yolk clamp properly on the leg?  A tight bolt may not be actually gripping the leg tight enough.
I know that you have redone all of this several times but once more will not do any harm apart from to your patience.

Dave.

craigc11g

  • Blue Star
  • **
  • Posts: 91
    • View Profile
Re: A10 S/A forks
« Reply #13 on: 16 September, 2020, 08:37:26 »
this is being tested with the bike under its own weight and not on the main stand ? ps bike looks great one of the best from bsa .

RESTORER

  • Blue Star
  • **
  • Posts: 69
    • View Profile
Re: A10 S/A forks
« Reply #14 on: 16 September, 2020, 20:58:54 »
Hi and thanks, this is all very useful for elimination purposes.  Eddie, I cannot find any play either with the brake strap tight or loose.  Dave, unfortunately I do not now have the old spindle, it was so bad I scrapped it off. I have put pic 1 in of the area when the bike arrived. I think the last owner must not have known about the LH thread and looking at the fork tube he was a bad shot with a hammer aswell, as the tube has dozens of little dents!  The movement is not springy and the bars stay where they are put, but what I have not said before is that the handlebars only move in one direction, when turning left (see other two pics 2 & 3). Also I don't know if this means anything but at the end of the left movement or when trying right, I can force the bars a little bit more but then they do spring back - your "natural flex" I believe.  Craig, the movement is the same either on or off the stand, except that off it is easier to move but I still have to hold the wheel with my legs. I confess to not understanding why you ask. Would you mind explaining please. Thanks all.
1954 A10 Golden Flash, Swinging Arm