Drop spindle questions

[ChadH]

I did a 4" narrowed beam to correct "poke" from installing CB drop spindles and disk brakes several years ago (this was link pin - but the same concept.) It changes a number of of things on the suspension/steering geometry:

* Shortening the torsion leaves increases the front spring rate. This would increase the ride height of the car a little, unless you installed adjusters to correct it.

* A stock swaybar will no longer work (as you already know), however the stiffer torsion springing somewhat makes up for removal of the swaybar.

* Both tie-rods need to be shortened. The shorter tie-rods make bump steer worse, and I believe it messes up the ackerman geometry a bit and increases turning radius. If I remember correctly, both tie rods are not shortened equally to minimize ackerman changes.

Having done a narrowed beam, I'd really discourage it if you are focused on optimum handling. In my mind, it's only benefits are aesthetics and eliminating tire rub.

[Ol'fogasaurus]

Good post Chad!

[ChadH]

One more thought..Is it possible the asymmetry of the tires is due to the camber adjustment? - One side is not adjusted the same as the other? Maybe it's not noticeable on a stock setup, but having the tire very close to the fender lip makes it more obvious.

[Marc]

* Both tie-rods need to be shortened. The shorter tie-rods make bump steer worse, and I believe it messes up the ackerman geometry a bit and increases turning radius. If I remember correctly, both tie rods are not shortened equally to minimize ackerman changes...

To make any significant change in the Ackermann effect you would need to alter the Pitman arm, or at minimum intentionally run it off-center when steering straight ahead.
The tierods need to be shortened enough to allow setting the toe-in. With the steering box & Pitman arm in stock location, if any more was cut from one than the other you'd just end up adjusting it so more threads were exposed.

The long/short tierod setup on a Standard Beetle works because even though there's no camber change as the wheel travels up and down, the spindle does move back and then forward again because the control arms swing through arcs as the suspension travels when viewed from the side. When you lower the car by moving the spring anchor points, the control arms end up closer to level (or in extreme cases, already angled upwards) at static height - so as the suspension compresses all spindle movement is forward. This compromises the original design which did a surprisingly good job of limiting bump-steer; in addition, the wheel can no longer "step over" obstacles by swinging back as it moves up. Together these effects mess up both the ride and the handling of a car that's lowered that way. "Drop" spindles retain all of the original geometry to avoid these problems

When I converted my last daily-driver to RHD I had to modify the LHD Pitman arm to reverse the built-in offset and retain Ackemann effect, but due to the lateral displacement of the steering box input & output shafts the RH tierod still ended up shorter than a normal LHD LH tierod which did impact the Ackermann a little. It was acceptable for normal driving but at low speeds when cranked to full lock either way there was more discernable scrub. I presume that the reason this hasn't been reported on narrowed-beam cars is twofold; they're limited to a wider turning circle so they don't ever reach the point where the Ackermann goes bad, and most are "slammers" driven by assclowns who have no idea what good handling is (lowering the CG does always have a positive effect, but in real-world conditions a properly functioning suspension is also needed).

[ps2375]

I run a BJ front suspension w/adjusters on my off-road Manx style buggy. BJ beam travel is ~ (roughly) 6 inches of travel most of which is limited by the BJs themselves. Remember, your '69 is a BJ beam and BJ beams do not have suspension stops; they use the shocks themselves as stops. Us'n off-roaders usually add "hoop and pin" stops to control suspension travel. There are specialty BJs for Class 5 (I think that is the class) that have the slots on the BJ lengthened up some to get a bit more travel. I do not recommend them for the street for several reasons mostly because they are modified and MAY NOT BE AS STRONG.

Also, if you notice the lower BJ is pressed in from the center of the spindle not from underneath as the "Thing" (Type 181) has. Too much travel can pull the lower BJ loose. More than you wanted to know but for understanding I think it is important.

(for some reason the video won't work in the new site)]

This was taken after a body lift and adjusters added but it should give you some idea of how much travel there is in a BJ beam. No hook and pins in this beam.

So, your saying lowering with adjusters have no effect on suspension travel? That is interesting info, but if I were to install them, I'd still have to cut and weld the beam.

One more thought..Is it possible the asymmetry of the tires is due to the camber adjustment? - One side is not adjusted the same as the other? Maybe it's not noticeable on a stock setup, but having the tire very close to the fender lip makes it more obvious.

As far as I can tell the camber on each side is the same or very close to being the same. I have them set for negative camber.

[Ol'fogasaurus]

"So, your saying lowering with adjusters have no effect on suspension travel? That is interesting info, but if I were to install them, I'd still have to cut and weld the beam."

Clarification: Unless you are running off-road or really beating on the car you should/probably not get to the limits with the exceptions of hitting pot holes or "turtles: (the large humped lane dividers, not the small itsy-bitsy ones. If your that low then you got big problems! ). If you think you need protection then add the hook and pins.

http://www.shoptalkforums.com/viewtopic ... A&start=15

This is part of a discussion on building a off-road BJ beam. Where I posted is the part of hook and pins. A lot of discussion here on that subject. The beam build was stopped because: 1) I made a gross mistake by not reading the instructions several times then marking out the sections that dealt with K&L adjusters and 2) the shock towers on the beam were rusted out inside worse than I originally thought. For what it is worth. Lee

[ps2375]

It's possible the backspace isn't identical on the rims, have you tried swapping them side-to-side?

Wheels are the same. Same amount of poke on the same side.

[Marc]

..So, your saying lowering with adjusters have no effect on suspension travel? That is interesting info, but if I were to install them, I'd still have to cut and weld the beam...

We tried lowering one of my son's cars by ~2½" with stock spindles and adjusters; used the long-slotted balljoints and Opel GT shocks which were still long enough when compressed to limit the travel (a lot of the shocks sold for "lowered" front ends are waaay short, to where you can't even bolt them up without a couple of friends sitting on the bumper). The balljoints lived, but the boots did not - they couldn't handle the extreme angularity.

Avis adjusters can be installed without cutting the beam apart (just slotting it) but it's only "easy" with a Brazilian beam that holds the center anchor block with plug welds...drill out the welds and the block can rotate, then grind a slot for the longer grub screw and weld the serrated plate onto the outside of the tube. If you can access the welds to drill them out, the lower one can even be done with the beam in place, and one might be enough in this case. With an OEM German beam the block has two flat sides which are locked in place by crimping the tube against them, with those you have to heat both crimps and force the block against them to iron them out so it's freed to rotate...possible, but not fun even with the beam out
The Sway-A-Way style require removing a section of the tube to weld them in, so care must be taken to not tweak the beam out-of-straight in the process. Doing one at a time and using short beads so the heat doesn't pull it works. Personally I use a big steel plate I made to bolt the beam halves to so they can be shimmed straight while welding them together (rather than cut up good straight beams for racecars I'd scrounge ones bent on one side from the wrecking yard, usually for free or close to it, and build a lowered beam out of two straight halves). Bear in mind that the lateral location of the center grub screws affect camber on both sides, so if this is done carelessly you can end up beyond the range of the eccentrics to correct.

[ps2375]

I'm thinking I'll put the stock spindles back on to see if the poke is still there. Then plan on narrowing the beam and reinstall the drop spindles after it's been narrowed. The adjusters will be another decision to make along with either narrowing the sway bar or buying one.

Being that this should be an OEM German beam, an "easy" install of that won't be anticipated.

[ps2375]

Stock spindles are back on and it looks as though the poke is still there, possibly not as much, but we do know that drop spindles do push the tires out some. Anyway the other side is tucked or nearly flush with fender like it was with dropped spindle, so it just wasn't as apparent at stock height as it was with the drop. I'll most likely narrow the beam a total of 3". My measurements with the drop spindles would have 2" on pass side and 1" on driver's side. I think I'll pass on the adjusters for now and be happy with the drop the spindles provide (as I was quite pleased with how it looked and drove). If the shortened leafs stiffen the from some, that will be great and if they take a 1/4" to 1/2" of the drop away, that will be fine too.

This will give me some additional time to decide what to do about the sway bar. And while the beam is off for the narrowing, I'll be able to clean up the threads on the pass side tie rod (as I have been wanting to do, already did the other one) and clean and paint them or even powder coat them.

[Marc]

IMO the Sway-A-Way springs would be the easier (if not cheaper) approach if you're only getting a tire rub on heavy dive.
Do you still have OEM-style shocks that have the rubber snubbers on the top? Just having those could be enough to make a difference by limiting dive. New snubber kits are still available, but they only fit OEM-style shocks which only come in one flavor, basic twin-tube oil shocks. Happily, those are quite adequate for street use. Stock length is too great for more than ~1½" drop with the springs alone (at that point use the Opel shocks)


If you're satisfied that the rim backspaces are identical and that there's no (easily-remedied) mechanical issue, you could approach this problem from the other end. Line the rolled lip of the front fenders with masking tape and take a spin to see exactly where the rubbing's occuring. If the interference is fairly minor, you may be able to cure it by simply tweaking the fender a tad. A baseball bat on the tire, held up against the fender as the car is rolled along, may do the job without damaging any (visible) paint.

[ps2375]

I have Bilsteins on the front, and the rub was basically under ANY braking, no matter how gentle I tried to stop. The side with the poke was less than 1" from the tire when sitting there, so I'm sure when driving it was getting very close to fender with any braking or road irregularities, if not rubbing more than just under braking. But that is when I would notice it.

[Marc]

...the rub was basically under ANY braking, no matter how gentle I tried to stop...

Oh. I was under the impression that it was just under certain combinations or turning/hard braking. In this case the stock shocks/snubbers wouldn't help....still worth looking into tweaking the fender, though.

[Ol'fogasaurus]

Stock spindles are back on and it looks as though the poke is still there, possibly not as much, but we do know that drop spindles do push the tires out some. Anyway the other side is tucked or nearly flush with fender like it was with dropped spindle, so it just wasn't as apparent at stock height as it was with the drop. I'll most likely narrow the beam a total of 3". My measurements with the drop spindles would have 2" on pass side and 1" on driver's side. I think I'll pass on the adjusters for now and be happy with the drop the spindles provide (as I was quite pleased with how it looked and drove). If the shortened leafs stiffen the from some, that will be great and if they take a 1/4" to 1/2" of the drop away, that will be fine too.

This will give me some additional time to decide what to do about the sway bar. And while the beam is off for the narrowing, I'll be able to clean up the threads on the pass side tie rod (as I have been wanting to do, already did the other one) and clean and paint them or even powder coat them.

Have one or both of the fenders been replaced?

Do a measurement from the lip to the body where the fender bolts on. Also look to see if there has been damage to the body where the fenders bolt on. Worth a look to see if they are the same or different distances. Maybe someone would be gracious enough to do measurements on their stock rigs just for comparison.

I wish I could help more on this.

[ps2375]

I mentioned earlier, that these are the OG fenders and no body work done to front of car(or anywhere on it for that matter). But, I will make those measurements. I was talking to my father about it (as he was the PO since about 1976 or so) and he was as confused about it as am I.