Hello All,
I welded up Aaron's frame and it is quite solid. John stated that:
Displacing the fulcrum point upwards will NOT cause the frame member or cross
members to break. These frame members can break after 30 years of viabration
and impacts. the frame members are normally 1020 steel and 3/16th thick. This
change causes the original mount bracket I.E. 3/32" thick to diflect in a
horizontal direction towards the center of the car. However this deflection
is limited due to the mount plate being butted up against the body. It CANNOT
move more than 5/16" inwards. This is not enought to cause stress fracturers.
Also I have NEVER had information of a mount plate attached to the frame
breaking.
I agree, however Aaron's tube shock mount does not move in and out toward the
body but fore and aft as the shock works. You can see where it has "worked" in
his photo:
http://www.triumphowners.com/uploaded/34/4978-4978-111032_35dscn2714.jpg The
top is rigid perpendicular with the frame. When the shock compresses it pushes
the top of the mount backwards, conversely on rebound. The original shock
mount is not designed to handle fore and aft twisting movement.
I believe an option is to stabilize the top of the mount with a brace running
back to an already existing hole in the frame. Boxing the backside of the
cross brace may also reduces twisting. After all, like John says these frames
are 30 years old!
Aaron's car handles better than mine with the tube shocks so I will someday
make the change.
Rick Patton
Not an engineer but do have a bit of experience fabricating.
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