BRAKE REACTION BARS
by Gerry Willburn and Lorne Goldman

Smart trad owners all use them, the Factory install them on request....but why?

Too many owners, don't understand them. They put them on because someone tells them to. As I an amateur, myself, I dislike that. One of the great gifts of Morgan ownership is that they can lead to  mechanical and eletrical understanding that can massively benefit your life and not merely your Morgan (s).

Morgans are not perfect..though they CAN be so with a bit of common sense and this Manual. Auto mechanics is not magic.

(Lorne) Brake reaction bars (or Upper Cross Axle Braces, as they were once known) address the movement of the top of the suspension pillar and locates it with respect to the chassis. There is already a brace from the bottom of the pillar back to the chassis to locate that end. However, under hard braking, the top of the kingpin assembly moves under that force to ill effect, being that wobble of the front end you feel..which also reaches the steering wheel. Hard braking is urgent enough that you do NOT want to be controlling the steering wheel at the same time! There are two basic sources of this movement; (a.) the action of the suspension itself, particularly on washboard surfaces and (b.) rotational reaction from braking stresses.

(Gerry) I must admit that when I first put them on our DHC back in 1959, I had never even heard of brake torque reaction. I was addressing the movement on uneven surfaces which (in addition to making the steering a bit vague) caused cracking of the front wings just inboard of the wing lamps due to movement of the wing stay attached to the top of the pillar. These cracks began to appear within weeks after we bought the car! 

I asked Chuck Talbott (then Tech Editor of the Morgan Plus 4 Club) and he told me that all of the racers had installed a brace from the top of the pillar to the chassis where the damper blade is attached.  I built them myself (as well as for all of the Morgans I have had through the years). All were made from aluminum and  I used thin wall electrical conduit tubing.

After cutting approximately to length (a little long), one end is flattened with a hammer on an anvil (or the end of a vice) and drilled to take the oiler bolt at the top of the king-pin. This is then bent to the angle required, the other end measured and flattened.  It is bent to shape and trimmed as necessary, then drilled to take the forward damper blade bolt.

It is a very simple installation. The only trick is the avoid accidentally nudging the kingpin assembly after you remove the top bolt. Take it out and then immediately put the bar and bolt back on and thread the bolt, to secure it but not to tighten it completely at this stage. I am concerned that you lose the exact alignment of the top bolt into the kingpin threads and or the kingpin and the main spring dislodge. (That is dangerous!!) Then let it find its proper spot on the frame, drill that hole and tighten the two bolts. I have never seen any indication of damage to the frame through their use.

One precaution is to use bolts weak enough to shear in an impact. The Mulberry and Heart of England versions are supplied with such bolts.
 
WATCHPOINT:  (Lorne) Brake Reaction Bars are made of a number from a number different metals and formats and levels of sophistication these days. They can also be purchased from Peter Mulberry Fabrications (Mulfab) or Heart of England Morgans (John Worrall) or Librands. (See the Morgan Masters Page.) There is also a write-up on making and fitting them in Cuthbert Twillie's famous A Yank in Malvern and that is the source of the diagram above. They can even be as effective when made from a flat metal strap you can find as scrap.
Update July 2012: I have noticed that the Factory has copied the Mulberry design (a habit they have had, copying any aftermarket design they like)  and is now selling them in stainless through their dealership network. I have no reports as yet on the strength of their retaining bolts. 

The first thing I noticed after installation was how much better the steering felt in rough corners.  The cracking of the wing ceased (and was covered up by installation of wing mirrors over the top of the existing cracks and bolted through the wing stay). I have since installed them on every Morgan that Barbara and I have owned and several

others for friends.  I think they are beneficial to all Morgans. I have always installed them "to fit" and never made any attempt to adjust caster through them.  I am the most surprised that they only recently (in the last several years) re-surfaced as a "new" innovation in England.  (wryly)

(Lorne) The second thing they prevent, especially for those of use, like racers, who brake hard and often is the deadly bending of the cross-frame. This can be a lot (see John Sheally II's old cross frame comparison below), or subtlely enough to alter your front end dynamics without you knowing it.



THE MOST IMPORTANT WATCHPOINT in this process is the one alluded to above. Where Morgans are at their unintentional best is the amazing crumple zone effect they have....many years before Formula One and then regulatory authorities realized that safety feature. It saved the lives of my wife and I in 2002.  My wife and I survived as the Morgan flexing ladder frame, eliminated in 2020, combined with the wooden tub also eliminated at the same time, absorbed impacts before they reach the cockpit.

In the front part of the car, Morgan frames pleat at the bulkead, allowing the entire front suspension and the engine to resist the impact force's egress before they too reach the cockpit. (I have seen the Aeros react the same way). Though unplanned, this crumple feature is fantastic. Morgans do have unsafe areas, but with a neglibile amount of money and good sense, they can be cured.

So the trick is to use these reaction bars to steady the front end, providing the great benefits discussed above but WITHOUT eliminating the natural safety elements and having these bars transfer impact forces in an accident to the cockpit. To achieve this is merely a matter of using weak bolts that will shear in an impact but are strong enough to do the joib intended. As Gerry noted above, we are not sure the what bolts the Factory uses with THEIR kit. I use tjhe pretty polished bars shown above..and they will shear not only at the bolts but at their bend pleats as well.