The brake reaction bars (or Upper Cross Axle Braces, as they were once known) address the movement of the top of the suspension pillar and locate 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. There are two basic sources of this movement; (a) the action of the suspension itself, particularly on washboard surfaces and (b) reaction from braking stresses. Many have simpkly become used to the vibration of the front when braking, especially hard. This costless fix has been used for decades and will cure that.
"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. 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. There is another reason
for this. The flexible steel frame and wooden tub of classic Morgans absorb
impact forces..thereby sacrificing themselves rather than transferring
that deadly force to the occupants. We do not want to add anything that
can change that. It saved my life. Lorne CLICK
|WATCHPOINT: 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. They can even be very effect made from a flat metal strap. Update July 2012: I have noticed that the Factory has copied the Mulberry design and is now selling them in stainless through their dealership network. I have no reports as yet on the strength of their retaining bolts or how they react in an impact.|
The first thing I noticed after installing them 25
years ago 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. Gerry