Paul wrote:

Here is a picture of the 22001 Barry rubber bushing
installed on the nose gear. The bracket must be drilled out
with a 3/4 inch hole. I used a hole saw.

The static load rating on this bushing is 250 pounds. Far higher than any
shock absorber bushing. The next size up will give you up to 630
pounds static rating but you will have to sleeve the hole in the rubber
mount steel spacer with another smaller steel spacer 1/2 inch OD with a 3/8 ID.

Page 956 in the 105 Mcmaster Carr catalog. $5.50
Comes with snubbing washer.
Vibration Control Mounts in the index.

Paul Lamar

The Barry mount rubber that you are showing is roughly the same size
as a rubber shock set (which is demonstratably over 250 lb static
capability). It appears that you are not clamping the bracket, becase
of the height of the reduced diameter center. I have no feeling
against increasing the rating of this part, but it should be clamped to
resist movement in both the bound and rebound directions. The
shock we use is designed to limit the down travel on an auto
live axle rear end, where it regularly would see loads in excess
of 250 pounds.
With that rubber add another washer/spacer such that it will clamp.
Vance

It is almost twice as large with roughly four or five times the volume as 
the shock absorber rubber bushing I got with the kit. If it was truly twice
as large it would be eight times the volume.

Much depends on the durometer of the rubber, the volume of the rubber
used and the chemical composition of the rubber. Various loads are available
for the Barry by changing the chemical characteristics of the neoprene. 

The difference between the shock absorber  rubber and the Barry
is the shock rubber is not designed to withstand a static load. The Barry is.
The nose gear constantly sees a static load while parked and a much higher
load when landing. 

In normal operation with the car stationary or moving over a smooth road 
there is no load, static or otherwise, what so ever on a shock absorber rubber 
bushing. It only sees a max load when the axle is in full rebound (rear 
tires in the air) over a big bump at high speed which is a very rare 
situation indeed. Up travel is always limited by a device called a bump 
stop external to the shock.

I would not think of designing a spring shock unit for a car and use a stock 
shock absorber rubber bushing. Look under the hood of any car with a McPherson
strut front suspension and you will see rubber bushings as much as four or five
inches in diameter and several inches thick  at the top of the struts.
Even in very small cars that weigh about 2500 pounds. That is maybe
700 pounds per corner static given typical weight distributions. The volume of
these rubber bushings is enormous compared to a shock absorber rubber bushing.

The Barry bushing I choose has a static load rating of 250 pounds.
I am not sure how much static load on the Cruiser nose but that is 
in the ball park I would guess. I can get bigger ones if needed.

It is not completely installed Vance. It will be clamped and bolted to 
the firewall when I know the exact load on the nose gear.

Paul Lamar
 
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