Calls for Change After Frangible Device Costs Riders Results

I’m primarily a lurker on the eventing boards (have a background in the jumpers; trying to find the right horse to eventually go XC), but I’ve followed for a number of years the discussion of “WTF are we doing” and the improved safety measures that are trying to be taken for the sport.

I was shocked today when, on my Facebook feed, the following article showed up from the Horse and Hound UK:

It reads as if some riders are now complaining about the frangible pins - stating that the deductions from activating them are costing them overall placings.

What does the eventing community say about this? Is it a valuable argument? To me - if you’re hitting a solid object hard enough to activate them - even if you’re not necessarily at risk of a rotational fall - it’s a problem; but I’m admittedly not an active participant and wanted to see what the CoTH community would say.


I say be quiet and be thankful that pin saved your life (or your horse’s!)


The article doesn’t sound like people want to get rid of frangibles, but bring back an appeal process for those who believe the pin was activated without warrant. If that many riders activated a pin at the same fence I have serious questions on what is going on there. Is the fence that unsafe or was the pin too sensitive?

Cross country shouldn’t be penalized like show jumping and if pins are being activated in instances where it’s not preventing a fall I’m all for the appeal process. If it’s all or nothing, my vote is to keep the franglibles, at the end of the day there is always another competition as long as you and your horse are alive.


this issue seems to occur at some low frequency, but perhaps the nature of the MIMS isn’t fully understood. The discussion which inevitably swirls around the topic is at the extremes – you should be happy because it prevented a fall, there shouldn’t be any penalty for a glancing trip of the MIMS, there should be an appeal / review, and so forth.

Clearly, everyone (I think/hope) is all for the prevention of rotational falls. However, with all safety devices ever invented, they are done at a point in time. They should never be considered the end of the safety journey. In cars we’ve seen seat belts… then raised center brake lights… then air bags… then anti-lock brakes… then proximity sensors… then collision avoidance systems… there will be more to come.

So, we should think of MIMS as a start, not an end.

I wonder if there are certain types of fences in certain configurations / scenarios which are more prone to the extraneous MIMS trips from a harmless glancing / sliding over contact. Perhaps that is being studied? No way of knowing. I hope those involved don’t feel their safety work is done.

It seems that the (harmless) sliding over / glancing contact is a different profile in terms of a force vs time curve describing the contact than a direct hit, which would cause a rotational without the MIMS. Yet, the MIMS is a static metal component with assumptions built in about that impact force curve. The design test videos of the MIMS, with essentially a weight on a pendulum swinging to impact the rail imply a limited “model” of what an impact is. I don’t know if there are/were more sophisticated models of an impact (direct high force, direct low force, angular glancing/sliding low force, force duration over short time, etc.).


The problem is not breaking a clip after a hard wallop but a clip going after just a rub when innumerable other horses have, similarly, given the fence a rub or even a thump without it breaking. At the moment there is no way to clearly, unambiguously see if the clip is still structurally sound after a rub. It largely depends on how good an eye the Fence Judge has. Currently there is no appeal by riders against penalties for a broken clip though there was a process in the past. The rule was changed either last year or the one before, I think.


I know at the Tokyo Olympics the clips were changed between every rider, regardless of activation status. I haven’t seen reporting one way or another from Pau, but would have to assume all the major events do things fairly similarly in that regard.

This is largely true, but a quick clarification - because of exactly this, there are two different sets of MIM clips, designed to be activated with two different levels of force. Per the current regulations (I’m paraphrasing), fences that are approached head-on use red MIM clips, which take quite a bit of force to activate. Fences which are designed to be approached on an angle (corners, I believe angled gates, etc) use yellow MIM clips, which take less force to activate (but still very far from none, it doesn’t become a show jump) because a “head-on” impact with an angled fence is actually technically more glancing (because taking a straight approach means you will meet the fence at an angle).

I think it’s valid to question course design in an instance where the clip came down so many times, insofar as it’s fair to ask whether the jump should have been placed there. It’s also fair to consider whether the line of travel suggested by the question meant that the horses met the face of the fence angling across the front rail (the situation the clips were designed for, how you would traditionally jump a corner), or if they met it more perpendicular to the front rail (meaning it would take less than the intended force to deploy).

However, I will say that having watched Pau, I did not see that frangible come down from anything I considered to be “just a tap”, and it saved at least one, likely two, pretty ugly moments. Would every horse that took it down have fallen? I doubt it. But a few sure looked like they would have, and the others did jump poorly at best. I think course design could probably be improved here (but overall was excellent at Pau - very influential, tough time, but no bad pictures), but the riders that had pins did not ride the fence well. I don’t have a problem with the outcome in this case.


Right. The Yellow MIMs break at 70% of the force which breaks the Red MIMs. They assume that the impact is at an angle to the fence (with the yellow MIMs).

There is a more subtle point, to which I was alluding. The MIMs makers mention, particularly with the Yellow MIMs, that they could be activated by people leaning on or sitting on rails. So, they have a Silver cup mechanism which can be installed to prevent this false activation when the fences are not in use. Inherently, the MIMs can’t distinguish between a rapid impulse force, and a slow resting force. If the force is above it’s static limit, it activates, regardless of whether it is a rapid impulse, or a slowly applied force (like leaning on a fence).

A more sophisticated mechanism would be sensitive to the “rate of force application”. So, a direct hit, or angular hit would trigger it. But, sliding over a rail would not. There are examples of materials that have non-linear force response. Sometimes they’re called ballistic materials. They feel soft at low force and low rate of force application. But, at high instantaneous force application, they activate and are rigid. An example, is certain protective body armor.

Let’s hope for continual safety process improvement, not just saying, well we got the MIMs so we’re done with that.

Have a great safe ride everyone!


I do think this is correct. Some rotational falls can happen quite slowly, but will be nonetheless damaging to horse and rider. Sliding over a fence does still happen at a fairly high rate of speed. Unless there is a way to distinguish a slow rotational from a slide-over-the-fence, I think the clip sensitivity needs to stay as it is.

Agreed. I think there is a lot of work left to do. Course designers must continue to evaluate where it makes sense to place fences, and it may make sense to tweak the yellow MIM rule such that designers can choose between red or yellow depending on how they think the question will be navigated, not simply required to use yellow because “it’s a corner”. Always room for progress!


I think we are in agreement on this.

Note though that the “speed” in this case isn’t the speed of the horse (whether sliding over the fence or a direct it). It is the rate of increase of the applied force to the rail, which then triggers the MIMs. Certainly, horses which glance or graze over a rail are traveling at speed, perhaps even higher than a horse which is buried and can’t get his knees up and has a direct hit / rotational.

I wasn’t advocating for changing the peak triggering force. I was exploring whether there is a design concept which allows slower rate of force application to be tolerated.

What I would do is make some “instrumented logs”, which record the applied force vs time, and study this relative to MIMs trips. This data, over time, may yield insights which could improve or refine behavior. The “instrumented log” could be done in a way which is compatible with existing MIMs and installations. I won’t get into the design here. But easy enough to do.


Ah, but the genius of the MiM clip is that there IS a mechanism that precisely indicates if the clip is compromised. They have an indicator flag.


Unfortunately that indicator flag does not move below a certain amount of force. Hit it hard enough, the flag moves, the clip is changed. It is certainly easier to both see the deformation and to change out the clip than when a fence has frangible pins. There is no way to see if a horse, a second horse, a third horse… a ninth horse… hitting/tapping/sliding over the fence without sufficient force to activate the pin, or move the flag, nonetheless have weakened/invisibly deformed the metal, such that some unfortunate competitor taps the fence and the pin finally breaks through cumulative forces. Didn’t Jung have a pin break after he was over a fence? Some visual marker, a line or a horizon, to clearly show cumulative wear would be useful.


Published by the FEI, following PAU 5* (XC):

"Dear FEI Eventing Officials,

We would like to inform you that further to the issues raised by the athletes following the CCI5-L Pau (FRA), 26-30 October 2022, the following statement has been issued:*

CCI5 Pau (FRA), 26-30 October 2022*

Representatives of the FEI Eventing Risk Management Steering Group have collected evidence from all relevant sources and undertaken a full review of the circumstances surrounding the release of the safety device on fence 21B (a corner in the water after a drop fence) during the Cross Country at the CCI5 in Pau (FRA), where 8 combinations incurred penalties.*

Pierre Michelet the Course Designer said “21AB was a true 5 star test with a drop into water over a big log and 3 strides to an open corner designed to be jumped at an angle. The best riders did this well. For some riders, they jumped in awkwardly and/or took extra strides taking off either too close or straight on to the corner deploying the frangible device. This was the 5 star test”.

“Two of the activations almost certainly avoided a horse fall which is exactly what the sport is trying to achieve” said Geoff Sinclair from the RMSG.

In light of all the evidence reviewed, which included video and scientific measurements, the RMSG concluded that the frangible device in place with yellow clips intended by the Course Designer to be jumped at an angle provided the expected release. The fence required an accurate approach and rewarded the riders with the correct line towards the angled corner. The Pau organisers ensured that the clips were changed anytime a horse touched the fence so that it was fair for every competitor.

The FEI has collected data for the past 20 years and has identified open corners as the fence type that cause the most horse falls. This is why a specific standard has been developed for fences intended to be jumped at an angle.

The FEI Eventing vision statement and the Risk Management policy in place states that the 5 star Cross country needs to maintain the highest level of difficulty as well as preserving the degree of influence on the overall competition results but with a safe approach. The result of the Pau 2022 Cross Country achieved this goal as no horse falls were registered during the test and the difficulty of the course was of 5 star level.

If you have any questions, please feel free to contact us.

Kindest regards,"


WHY are we still using open corners if they are KNOWN to cause the most horse falls?!?!


The clip cannot be weakened if the flag does not move. If the flag moves, the clip is expected to be replaced. This MiM system absolutely does eliminate cumulative stresses when correctly administered.

For some reason I seem to remember that when I started eventing (late 90s), open corners were not allowed. Am I misremembering? If not, when did that change?

I’ve learned a lot about MIMS clips in the past few hours. A stronger red clip has been produced since 2021 because some did bend without breaking. On the other hand, a yellow clip will break when 70% less force is applied than for red ones. That means they may break if a person walking the course leans on the fence, or climbs onto it. Special temporary silver clips can be used before the competition to keep the fence intact. Who knew?

There is a lot about frangible and deforming safety devices on the FEI website under Eventing Safety, including an interesting video meeting about how to use them.

1 Like

Right, and as many fences/combinations at 5* level are often jumped at an angle, so…
Are 5* xc tracks to be dumbed down and we forget about the 5* standards altogether, OR we continue to develop and improve frangible technology and their use?
Lives were saved, the frangibles did the job where, in the past, they meant (often fatal) rotational falls.

As a reminder, at Pau: Out of 48 starters, 8 pairs got the 11 penalties at 21B, with AT LEAST 2 horses saved along with their rider’s ass!
Those who rode the 21AB combo the way it was meant to be ridden showed it wasn’t designed/meant to be dangerous.
Those who didn’t, paid an insignificant price considering…

I also have painful memories of many terrible rotational falls over wide tables, or other straightforward fences not jumped at an angle.
Should they be taken out too?

So, what do you suggest? :thinking:


There have been changes: tables must now have a higher back edge than the front. All fences must have groundlines. Some tables are now built with frangible technology. Course design guidelines include suggestions on contrasting colours for spread fences.

I could do without the maximum width essentially square tables, myself, especially when they seem designed to cause issues - e.g. the ones with “peep hole” cut-outs which are meant to distract the horse.


If you don’t mind, can you share the source of this information ?


I was rather surprised at the cost. On the other hand, the company puts in far more research for eventing safety than it will ever make back in money. The MIM clips are the way forward because they are quick and easy to replace unlike pins, though frangible pins do still have a place. Not allowed to use rope with pins now, must be cable.