B25 damper rod fork reassembly - stanchion puller needed?

[MadPete]

I am reassembling the "damper rod" front forks on my 1968 B25. From members experience is is necessary to use a stanchion puller tool to get the stanchion up into the top yoke - or are there any tricks I should know before finding the required tool (as I don't have one). EDIT: I note a tool can be made from old yoke nut and studding, &c. but have others found this necessary?

And are there any tricks with placing the rubber sealing washer and the steel retaining washer at the top of the spring (and under the bottom yoke). Should it be possible to place the steel retaining washer from the top of the stanchion - to slide the stanchion up and then into the bottom yoke through the washers. Maybe I have a steel washer with a smaller internal diameter. Oh err, missus, &c.

[MadPete]

Update: The answer to my question is - "A stanchion puller tool is not always required" and in my particular case it is not required. Amazing and very useful to know.

The problem that made me ask the question is the internal diameter of the supplied steel "retaining washer" (47-5064) that protects the rubber sealing washer under the lower fork yoke. The internal diameter was such that the washer caught on the thicker section of the stanchion where the lower yoke pinch bolts grip the stanchion. The washers could only be installed before the spring was located on the stanchion (and then all the other stuff and the fork slider). It could not be installed "from the top". This did not seem normal but it seems the washer is thick enough to resist the spring which can be slightly compressed to get the fork bushings and the slider on and done up. So the complete fork stanchion is assembled with spring in place under slight compression. After that the fork leg can be slid into position in the bottom and then top yoke. The top yoke stanchion nut can then be fitted and used to complete the location of the stanchion top taper in the top yoke. Or so I hope but I am most of he way there already.

Hopeful to complete it all this weekend. I have learnt more about damper rod forks that I ever thought existed! And one thing I have learnt is that many parts supplied "by the usual suspects" were just wrong. Hey ho. On with the show... :0)

[MadPete]

Tried assembling all at the weekend and my idea of simplicity fell apart. I did think of the problem that hit me while considering the rebuild process. My scheme of fitting the "built up" stanchions was perfect if the bottom yoke was correctly positioned at the bottom of relevant enlargement on the stanchion and butted up against the retaining washer/rubber seal on the stanchion. But of course "any fule kno" that isn't going to happen in practice.

The basic problem is that the supplied retaining washers are not the correct internal diameter - they are too small if only by a fraction of a mm (sorry "inch"). They don't fit on the original stanchions either so deffo wrong. As I am sure many readers will agree - modern parts really lack quality control. A part may be stocked but rarely tested in used before sale - and so the only way forward is to make or obtain the correct size washer - which I think is 1 3/8 internal diameter.

So now I have to put the washers in a lather chuck and take 1mm of the internals - of get a cone drill to enlarge them. Or find somewhere that sells the correct washers.

And to top it I have the same problem with the sealing washers I was supplied with for the allen bolt that holds the damper tube to the lower slider. The internal diameter is perfect but the external diameter is 0.5mm too big and it won't go into the "well" on the bottom of the slider.

Hey ho - on with the show... :0/

[MadPete]

Finally an end to my woes! I bought a Honda... (nah just kidding).

The seal retaining washers (47-5064) supplied by Draganfly were too small on the internal diameter. And no one else seemed to have anything different. Thankfully I have a friend with a lathe, so we superglued the washers together, stuck them in the chuck and milled them out by 15 thou. Perfect. Then heat them up until the cyanoacrylate melted and we could separate the individual washers. Now they run freely over the widest part of the stanchion and I can finally fit the forks to the yokes correctly.

I did something similar with the fork slider bottom allen bolt sealing washer (aluminium). I turned them down to just larger than the allen bolt head and they too fitted well.

What a palava and from a "known" supplier too. Do members have any particular recommendations for obtaining B25 parts in general? of the 15 odd items I have bought for the BSA forks approx 6 do not fit , at all!

[Tigerfeet]

I would consider getting nine parts that fit, out of fifteen ordered, to be extremely good going! I reckon on one in three being usable....

[limeyrob]

I've just spent an hour grinding out the inside of a mag points cover to get it to fit.

[MadPete]

Oh the joys of BSA restoration... but I am slowly getting there. Now to press out the bushes on the new rear shocks to replace them with a larger diameter bush.  :0)

[MadPete]

Well Spring is nearly here which prompted me to blue my springs and make a second attempt at fitting the fork stanchions to the yokes. Yeah, I know it's been a rather long break. I have had to move the big box of bits to a garage so I can paint the frame and and then get the engine in a rolling chassis. Phew!

When I left this task before Christmas I was wondering if I needed a BSA stanchion puller tool. Using a stanchion puller is the recommended method to do this task. But, after some experimentation, I found that I could compress the spring by hand and hold it with a pair of small, long nosed mole grips clamped onto the stanchion (between the coils of the spring). This allowed me to fit each stanchion separately and easily.

Here is the grip in place holding the compressed spring so I can easily insert the complete stanchion.


To make the spring compression easy, I screwed an old fork top nut into the top of the (fully built) stanchion and clamped a mole grip onto the nut. That way I could turn the stanchion upside down, stand on the mole grips clamped to the fork top nut and pull the spring up using my hand and the (unlocked) thin nosed grips. I put the grips though the coil a short way from the "top" then pulled hard to compress the spring. Then I clamped the thin nosed grips as best I could onto the stanchion. The grips hold the compressed spring in place. I then remove the top nut with large mole grip attached.

This allows me to manoeuvre the complete stanchion into the bottom yoke and up through the headlamp shroud and into the top yoke. I "wedge" the bottom yoke clamping point to make sure the stanchion can be freely pushed through it. Then I use the top nut/washer to pull the stanchion up snugly to seat in the chamfered top yoke. Then I remove the wedge from the bottom yoke and bolt it up tightly.

Now the fork stanchion is held in place, I can unscrew the top nut and retrieve and connect the damper rod to the top nut. I short length of previously attached wire (loosely folded down into the stanchion) can help here.

Once I had got my thin nose mole grips out of the tool box, I had this all figured out and on in an hour. Which included removing and refitting one stanchion when I lost the damper rod down the tube! It was a reasonably simple way to do the job, which if one is stuck only required two sets of mole grips (one larger and one smaller with thin nose)
The thin nosed locking grip I used was relatively small - less chance of damage.

[Janacek]

If you don't have the tool to pull the stansions into the top yoke,simply take a length of rope,loop it through a mudguard lug on the fork,tie the ends together and loop it over the top yoke,using a piece of brush handle or wood and wind the rope together to pull the fork leg into the top yoke.

[limeyrob]

I bought a universal fork stanchion tool of e-bay for about £40, it saved a lot of time. I'd wasted ages trying other tricks. I tried the "wooden pole" method, got it all screwed in and at the final bit it pulled out and dumped a load of splinters down the fork, that's the point when £40 went from looking expensive to very attractive

[MadPete]

If you don't have the tool to pull the stansions into the top yoke,simply take a length of rope,loop it through a mudguard lug on the fork,tie the ends together and loop it over the top yoke,using a piece of brush handle or wood and wind the rope together to pull the fork leg into the top yoke.

Not sure that would work so well in practice. It is the sort of thing I wondered about at the start of this task. Unfortunately the springs resist the the force pushing up to the yoke and the stanchion itself (being free to move) retreats back into the slider. After that it is a case of take it apart and pull the stanchion back out of the slide & repeat...

My trick leaves the stanchion in some tension so it can be pushed up into the top yoke with no real effort. No really special tool required unless you can't get use of some thin nose vice grips. And even if you have to buy some its cheaper than the special tool - and the grips can be of general use, unlike the special tool.

I do accept the special tool is the approved way to do this job. But this trick worked so well for me that I thought I had better tell the members here. If I ever have to do this job again , this is how I would do it.

[MadPete]

I thought About making a new post but same project and same problem, so I'm continuing with the sage of the front forks here... :0(

Now the forks are on I quickly moved to fit the complete wheels. Front wheel to forks should be easy - so I got the wheel and offered the spindle and brake plate up and into place. I thought all was good until I got the bolts and slider caps and tried to do them all up. I had great difficulty in getting them to screw in by hand. And similar difficulty in very gently using a wrench.

I took it all apart and noticed the "bolt groves" in the spindle did not line up with the bolt holes on the slider. Or more correctly - I could get one side lined up but then the other side would be 1/4" out. Using some soft force I could get both to line up but then the sliders seemed to be "splayed out". I quickly took it apart again and had a close look.

Some photos - on the OS (left) the holes do not line up with the spindle groove, while on the NS (right) it almost lines up but


This was an "eBay sourced wheel" (some years back) with a twin leading shoe brake plate. I thought "just my luck" to get a bad'un but wondered if the original wheel that the bike came with was any different. And the answer was not really but I did notice the hack....

Some more photos of the original wheel spindle:


On this spindle there is a second grove (sort of) on the near side. Hmmm. Not correct or useful. That would explain the flattened threads on the bolts... :0( Obviously not the correct item, in some parts or in whole. Strangely the twin leading shoe brake plate fits in both of the wheels... The original brake plate was SLS.

My question is - does anyone here have any comment or insight or wisdom they can impart? Does this wheel/spindle hack happen often? And how to rectify this - do I buy the correct spindle and rebuild the wheel or am I missing something? Besides a useful wheel... ;0)

All comments welcomed.

[JulianS]

The 1969/70 TLS braked wheel and the shuttle valve forks used a different, slightly longer spindle than the 1968 damper rod forks.

My recollection having fitted a TLS wheel in a 1968 B25 some years back is that I used the original 1968 spindle. Below the only photo I have of it.

[limeyrob]

This is minefield and (trust me) someone has gone to the trouble of producing a whole table of the wheel spindle lengths and grooves and fork legs for Triumph, but most of its applies to BSA too.
Some fork legs have the bolts offset, some not, and the spindles vary to suit.  Since there are so many combinations and only one works one way is to get the spindle in a lathe and machine it to suit your forks.  If you do go down that path spend plenty of time measuring to make sure you get the wheel centred and the brake plate right.  The fork leg "peg" varies too.
My A10 came with an 8" TLS that fitted wonderfully until I fitted new wheel bearings and found a home made spacer pushing the wheel over.  Ended up getting the brake plate built up with weld and re-lacing the rim back to where it should be.

[MadPete]

Thanks for the comments guys... I am happy and sad at the same time! Another local biker sent me this comment:

BSA started fitting Triumph brakes in '68 and, pre-'69, Triumph fork legs were only 6-1/2" centre-to-centre, whereas BSA's were always 6-3/4". So, just in '68, BSA's have one-year-only sliders to accommodate Triumph's 1/4"-shorter axle.

Seems like I need to replace the spindle i have with the shorter spindle. Hmmm.... now where to find one that is dimensionally correct. I wonder if finding a nice complete wheel would be a better option and my rims are not great.

EDIT: interestingly this particular subject is one that Mr Ratio's encyclopaedia does not shine much light on. I presume one can "just" rebuild the front wheel with the shorter spindle... I might order a spindle and offer it up to the sliders in situ. If it lines up then that is the way to go. Unless I can find a good wheel with the correct spindle. Any offers? :0)

This is minefield and (trust me) someone has gone to the trouble of producing a whole table of the wheel spindle lengths and grooves and fork legs for Triumph, but most of its applies to BSA too.

can anyone point me at this table, please?