Steering Arm routine bring up

[John Raeburn]

Hi john,

an experience nobody wants to go through. I'm happy to here you wasn't injured.

Perhaps Austins, "design falt " worked in the way it was intended. Under load on a roundabout or in a car park.

If Austins design fault wasn't there it may have been far worse at 50mph.

May I ask if and when the arm was tested before it gave way. As these cracks let alone a failier normally take years to happen.

And also what checks you have planned in the future for the new arm, or will it be a fit and forget item.

I know the questions are controversial, but they are only in interest to how these parts were used in the past, and how they will be used in the future.

Tony.

Hi Tony,
No I was't hurt at all, but finding your self nearly upside down in a Seven does tend to focus the mind!!
Was the arm tested before it gave way? No not at all, in those days I didn't know that is was likely to be a problem, and you know I just replaced the broken one with another, assuming it to be a "One Off" incident, mind you that one lasted for years. But the thought of an arm failing at 50 mph. no thanks!
Davids replacement arm is a better design with a much larger radius, the same as on the Big Seven, and I have never heard of a Big Seven arm letting go, which leads me to think that Austin's knew that there was an impending problem,
but we shall never know for sure. 
To this day I still look at steering arms and think Mmmm.
J

[Tony Betts]

Hi john,

Thanks for your honest answer.

It goes to show that steering arms should be crack tested from time to time.

Tony

[Colin]

Well well. Mr Williams and his chums strike again!
At 76, I have learned tolerance and appreciation of other peoples opinions, whether agreeing or not. I have certainly long grown out of the childish habit of rounding up on the different, whatever the situation or reason.
This type of arrogant behaviour is un-befitting this forum!!
Carry on pontificating Bob. I will respect your right to expresss your views and opinions.
To you all, a Merry Christmas and Happy and Prosperous New Year.

[Bob Culver]

This began as a serious well meaning post but has strayed far and wide, and attracted comments based not on the actual complete literal words but on some entirely imagined motive I am alleged to possess.

Any references by me to safety are not snide cracks at the competition fraternity. They know their vehicles intimately and the total situation. Many other owners are not so familiar.
(As for trialling, I suspect the greatest risk is the road trip in traffic  to the venue! If not risk averse why the chains on the spring?)
 
I make no secret of the fact that I do not have a car on the road. A degree of detachment assists objectivity! It could be argued that experience  from very extensive everyday city and open road driving when Sevens could keep up with much of the traffic, is more informative for normal vehicles  than much modern usage, including racing.
If I was driving every day the physics of metal fatigue and the number of dubious steering arms would not alter.
 
I made no reference to comparing apples with apples, but the matter of Seven relative frailty, reliabilty, safety cf contemporaries  could make an interesting topic.  However it would be impossible to contain on a rational level.  Comparison would include the 1935 Ruby vs Morris 8 with brakes etc ....
The factors which make an intriguing hobby car of choice are not the same as applied when new.
 
Hopefully someone else with a conscience will repeat this bring up next year and avoid the nonsense which it triggered.
 
I thank those users who responded rationally and especially those sufficiently bold to express support.

[cardiffrob]

I took mine off and polished the inner surface to reveal that the arm was cracked perhaps 25% of the way through at the surface. Not sure how far it had broken inside the structure.
It was a case of polish, hot oil, dry right off, clean surface, hit with a soft mallet to squish the oil out a bit and then dust with talc. Nice black line emerged. Maybe took 20 minutes to do.

[Dave Wortley]

    This is an arm showing cracks on internal spigot radius. Not easily spotted without taking off the car

[Ruairidh Dunford]

Dave,

are you prepared to destroy (snap) it and report back please?

[Dave Wortley]

R,
I can have a go but my 4” vice may be the first to break!
Cheers,
Dave.

[Ruairidh Dunford]

Thanks Dave,

I have a good number here but none show any cracks, otherwise I would do it myself.

[Dave Wortley]

R,
Just had a go at trying to propagate the crack in the corner rad in the spigot using a 4 ft scaffold pole.Succeeded in bending the arm over its length by 10 deg but no alteration in crack size. Also managed to move my bench by 2ft. Arm going in scrap bin. Dave