18-10-2021, 10:35 PM
Hi Denis
Originating from experience with our Seven beginning with a broken steering arm in 1950 I have taken a long term interest in fatigue. In constant load lab tests only 10% of life remains after initial miniscule crack but the real world with fluctuating loads is very different. From the sheer number of cracked cranks and steering arms these must operate cracked way beyond 10% of total life. Curiously early overload can extend life! So a few bunny hops with new axle and early prising of the car out of parking space may be beneficial!
(With cast iron the life cracked is very considerable. An uncracked ci Bradford crank is a great rarity and probably a replacement)
Originating from experience with our Seven beginning with a broken steering arm in 1950 I have taken a long term interest in fatigue. In constant load lab tests only 10% of life remains after initial miniscule crack but the real world with fluctuating loads is very different. From the sheer number of cracked cranks and steering arms these must operate cracked way beyond 10% of total life. Curiously early overload can extend life! So a few bunny hops with new axle and early prising of the car out of parking space may be beneficial!
(With cast iron the life cracked is very considerable. An uncracked ci Bradford crank is a great rarity and probably a replacement)