The crank shafts have a radius on the shafts that come out of them to prevent the shaft from breaking under stress. Machined parts should have a nice radius and bolt holes should have a small countersink to prevent cracking. You can see that the inner sprocket has a countersink on the inside to fit over the radius. High grade bolts put a small radius where the threads end and under the head to make them resistant to breaking.
Handy,thanks for uploading
Hi Boz, thank you for this info, can't get it anywhere else. Did you finish the smart 450 project?
I did finish it a while back however both cars have now been moved on.
The crank shafts have a radius on the shafts that come out of them to prevent the shaft from breaking under stress. Machined parts should have a nice radius and bolt holes should have a small countersink to prevent cracking. You can see that the inner sprocket has a countersink on the inside to fit over the radius. High grade bolts put a small radius where the threads end and under the head to make them resistant to breaking.
Great information.
Spot on david thanks !!