Isolation Plate inserts - a board failure risk?

[SunSurfer]

A word of caution around UPM inserts (and by extension Allflex inserts as well).

This photo shows my now mortally wounded Coiler NSR 182, a custom build for me in 2013. It was fitted with standard UPM inserts, and at my request Bruce added an extra insert set 4cm beyond that. I have posted in the past the setup that utilised those extra inserts allowing me an interaxle distance around 72 cm and a total plate height (with a Bomber 4mm plate) of approx. 21mm. When I rode it I found myself effortlessly carving at up to 70km/hr (post event tracker app data) without actually trying to go fast.

The laminate failure shown goes right through the front heelside extra and outermost insert. I suspect this was caused by riding that plate setup in lumpy end of the day snow conditions. The plate allowed me to carve in those conditions, but it also allowed me to exert forces that were beyond the capabilities of the NSR's construction with those inserts. On the same trip I had ridden old, stiffer, more heavily constructed boards with self added UPM inserts (Riot Supercarve 180cm, Pale Spook 174cm, Hot Blast Slalom 160cm-Red) without them failing. They don't have that beautifully smooth initiation of the turn that a recent Coiler provides, but an isolation plate makes them all remarkably good rides even in late day cut-up snow.

I've done a post-mortem via e-mail with Bruce, and he commented that he doesn't like putting UPM inserts into boards, that each extra insert creates a further weak point, and that he has had a number of boards fail like this. As I contemplate a replacement for the NSR (heading towards a 180cm Nirvana Energy - Torsion Plus, with a spot reserved on the Coiler 0.3mm Titanal build list) I have been weighing up asking for UPM inserts given my well known preference for riding with a plate, but now balanced by Bruce's comments above. I suspect I will go with no extra inserts and ride the coming Nirvana without a plate.

The farther out from the centre the plate inserts go (Allflex are a long way out) the thinner the board core at that point, and the weaker it becomes. The farther the inserts go out the greater the torsional resistance effect added by a stiff plate and the better the edge hold. Plates allow us to hold a carve in marginal conditions and clearly even though they allow the whole board to flex in response to bumps beneath us, they also allow us to place enormous forces on the board. It may well be that boards optimised for use with plates need to be of significantly heavier construction to minimise this risk of failure and that may be at the expense of the silky smooth feel that Bruce is able to create for his non-plated recreational boards. It strikes me that this may well be a reason why plates may only be really suitable for heavily built race boards.

[lowrider]

In the name of science you have to at least have the inserts installed in the new build even if you plan not to ride it with a plate!  You will be ending your exhaustive research without adequate data. Sorry for your loss. 

[Corey]

That sucks!  Is there a point in your pivot design where it locks up?  Is it possible that it flexed that far?  

You raise a valid point - the ability to suck up bumps may have allowed you to charge through conditions that would have given you pause before.  

This is a selling point for the Apex V1 plate - the duckbill will help to spread stress into the plate if/when it bottoms out.   

[SunSurfer]

Corey, I checked the pivots at both ends when I discovered the damage, everything working and pivoting perfectly and the slide has about 2cm available travel, way beyond anything that should be needed without having the NSR bent up around my ears! No possibility of plate impingement causing a lock up either. Note that the crimp has occurred through the insert line, not at the edge of the UHMWPE block that the hinge mechanism was mounted in.

Lowrider, the incident has left me weighing the myriad compromises in making a snowboard and in its' subsequent performance. Bruce has said he probably won't be making boards for too many more years. 0.3mm Titanal may well not be available to makers like him any more and so a future Nirvana may not quite hit the same sweet spot across multiple compromises that is a current Nirvana. This may be the last of Bruce's works of art that I get to buy. I would like it to ride it for as long as possible.

My wife knows me well. When I told her what had happened she suggested I keep the NSR as wall art and that I buy a replacement. Hopefully, one day, a long time from now, the Nirvana will join it.

 

[Apex Insider]

If you stick with the standard ASIP (UPM) insert spread of 64cm, the risk is minimal. There is plenty of core material at that point. However, when you push the inserts out to 72cm like your custom pattern or 78.4cm like Allflex, then the core becomes very thin and the risk becomes real. The risk is further magnified by the fact that the Allflex pattern has 4 inserts placed across the board instead of 2. 

I know that a lot of board manufacturers resisted the Allflex pattern for this reason. But, after 2-3 seasons of building, they have adjusted their construction methods so that breakage is less of a problem.

For a pro racer, who's career hinges on hundredths of seconds, board breakage comes with the territory. Us amateurs, who don't make a living on our boards, have to decide if the extra performance advantage of an isolation plate is worth the added complexity and cost. There are other plates that offer leverage and dampening and still use the tried and true 4x4 pattern.