Hi,

I have a very long 2-piece propshaft for my bike powered kit car.

Front half is ~50cm and rear part ~80 cm long, there is a middle bearing on the rear part of the front half.

I would like to install several prop catchers in case the propshaft fails to avoid personal inury.

Can you advise me where the ideal locations are to place them?

I read to place such prop catchers close to the U-Joints as those usually fail first.

Hence I would like to place a prop catcher close to the engine/gearbox flange and one close to the differential flange.

But what about the central u-joint which is holding both propshaft halves together?

Would I need to place two prop catchers there on each side of the U-joint?

Or do I only need one prop catcher on one side, as the middle bearing acts as prop catcher on the other side?

How far from the U-joint should the propcatcher be ideally located? I assume the ideal location would be a couple of cm away from the u-joint, on the tube side?

How much larger does the diamater of the hole in the prop catcher has to be compared to the propshaft? Is a 20mm larger diamater sufficient?

Can you recommend the thickness of such a prop catcher? Is 3mm mild steel with M8 8.8 bolts sufficient?

[Edited on 25/2/19 by reb]

[Edited on 25/2/19 by reb]

If all joints are the same quality, it is the front which will break because it's where power is initially driven into the driveshaft.

I always put mine just behind the front joint. Usually about six inchs, on a shorter shaft just move it a touch nearer.

2, 1 at each end is the simplest way to be sure.