How do you get "into" off roading?

[300bhp/ton]

PugwasHDJ80 said:

I'll pick up on this-

you do get sudden jolt from the KERR if the vehicle you are trying to recover is very very stuck- when the KER has reached its point of maximum elasticity it becomes entirely taught- the problem you have then is that the recovery point is under huge load, more than a normal rope, at that point, if the recovery fails, and then the recovery POINT fails then you had aeound 6,000-10,000lb of thrust acting on something weighing 2-3 lb. Its incredibly dangerous.

With a normal winch rope, if the recovery point fails it tends to travel a short distance with relatively minimal force.

It is the same argument as to why dyneema (and its ilk) is safer than wire winch rope- no storage of energy.

If you don't understand why KERR's are dangerous for novices then i would suggest you need to consider whether you should be making suggestions to novices.

KERRs are great for specific jobs, at specific times, but not all and not frequently. In the UK a Winch is a much more controlled solution.

I don't believe I was ever comparing a KERR to a winch rope.

And I doubt it's that common to get so stuck on a ground with enough traction that another vehicle can pull a KERR taught. And even at that point, the loading will not be higher than a non KERR rope.

I accept if you manage to get full loading on a fully stretched and taught KERR, then should it fail at the precise point, it could cause a potential issue. But tbh, the chances of this are likely far more remote than simply ripping the recovery point off with a non KERR rope and causing all kinds of grief that way.

And a non KERR can and does cause a dangerous projectile when there is a failure. So the risk difference is minimal as an end result, but with lower risk of an incident in the first place.

Apologies for my first reply, I thought you were part of the above discussion, but that was my error. But I still stand by point.

[Ayahuasca]

A Kinetic strap HAS to be more dangerous than a regular rope as it is designed to stretch, like a bow or an elastic band. This means that there is no sudden shock as there would be with a normal rope, so in that sense it is safer, BUT if it fails it will fail much worse. The weak point is normally the attachment points, which tend to be made of steel, which will go through bodywork (both car and human like a cannonball).

In my car, the rear attachment is a Land Rover NAS step bumper with a pin thing:



The strap would go around the pin (not the ball); however on inspection the ball / pin assembly is only connected to the step with two steel bolts (like in the pic). There is no backing plate behind the bolts so I will be getting that fixed!!

[Cfnteabag]

Ayahuasca said:

I don't care about this discussion, I just want to be your friend!

[300bhp/ton]

Ayahuasca said:

A Kinetic strap HAS to be more dangerous than a regular rope as it is designed to stretch, like a bow or an elastic band. This means that there is no sudden shock as there would be with a normal rope, so in that sense it is safer, BUT if it fails it will fail much worse. The weak point is normally the attachment points, which tend to be made of steel, which will go through bodywork (both car and human like a cannonball).

In my car, the rear attachment is a Land Rover NAS step bumper with a pin thing:



The strap would go around the pin (not the ball); however on inspection the ball / pin assembly is only connected to the step with two steel bolts (like in the pic). There is no backing plate behind the bolts so I will be getting that fixed!!

I hear what you are saying. But just for clarification. A bow does not use an elastic or stretching string. The energy comes from the bow itself, not so dissimilar in theory to how a non kinetic rope would work.

The only scenario where I can see 'potential' for the kinetic rope to have more 'flinging' power (for want of another word). Is if you secured one end to something far more secure than a stuck vehicle and managed to fully stretch the rope. I would think you'd need some kind of winching device to do this (like a ratchet strap but bigger). Then release the energy. But a non kinetic rope would still have potential energy in such a scenario and both have the ability to fling an object.

In practice however, unless you are towing vehicles considerably above the weight ratings for the ropes, you are unlikely to be able to stretch the rope to it's limits. There most likely will not be enough grip and the tow vehicle will wheel spin, releasing the potential energy in the rope.

It's also vital to note, that when towing, we aren't talking about two static objects winding on extreme load to the rope. One of the vehicles is moving, and it's that movement that will make any failed recovery point fly through the air, regardless of the rope type being used.

And any snatch recovery that causes a recovery point to fail with a KERR, would also have happened with a non KERR strap/rope. But not necessarily the other way round.

[Ayahuasca]

Easy to model KERR / non-KERR effects:

1) take a piece of string, attach one end to a paperclip and the other end to your finger. Stretch your finger out. Release the paperclip.

2) now take an elastic band, attached one end to a paperclip and the other end to your finger. Stretch the elastic band out. Release the paperclip.

Which one hurts the most?

[DmaxSteve]

Standard Disco 3 can go pretty much anywhere even on standard tyres - though I they're better with the three types I tried ST's MTR's and ATR's

Video is a vanilla Disco 3 on ATR's - these are tracks from the BCCC 2015 Radnor Forest round
https://www.youtube.com/watch?v=U7WdUbCjl-E

https://www.youtube.com/watch?v=wmE8idVKSsY

https://www.youtube.com/watch?v=yoh5yvwPsaw

Edited by DmaxSteve on Friday 28th October 15:47

[Ayahuasca]

DmaxSteve said:

Standard Disco 3 can go pretty much anywhere even on standard tyres - though I they're better with the three types I tried ST's MTR's and ATR's

Video is a vanilla Disco 3 on ATR's - these are tracks from the BCCC 2015 Radnor Forest round
https://www.youtube.com/watch?v=U7WdUbCjl-E

https://www.youtube.com/watch?v=wmE8idVKSsY

https://www.youtube.com/watch?v=yoh5yvwPsaw

Edited by DmaxSteve on Friday 28th October 15:47

With respect, those look like very gentle routes.

[DmaxSteve]

Depends how hardcore you want to get - I took mine across Salisbury Plain, through Strata Florida in Wales and also up and down Pindale the now sadly TRO'ed) Roych Clough - much more than that and you're into the crash and bash brigade

And also did this...