TD2 Shoulder Bolt Failure

[jnshapiro]

In response to Fin...

I just checked my bindings. One shoulder bolt was snug and not as tight as it should have been. Every other bolt was tight. The offending bolt is tight now.

[D-Sub]

Ahhh... and therein lies the difference. The user knowing the problem existed for months and doing nothing.

which would admittedly make it worse. Some people don't even routinely check equipment though! Imagine if a skydiver or BASEjumper had the attitude displayed above?

How anyone can think that maintenance is a hassle is way beyond me.

I guess I made my point

and, alexey...nothing personal. It was you who stated "some people might think..." and I'm not even assuming that you feel that way. Simple fact is, anyone who does doesn't belong on a snowboard. Especially an alpine snowboard.

[yyzcanuck]

I guess I made my point

Sorry, but I've missed it then. Could you restate your point?

[D-Sub]

nevermind. not worth the hassle.

[tpalka]

Anyone willing to post here if they do, it would be an interesting poll?

Just wanted to say that I too ran into one of these issues -- I had the lug bolt turned around 180 degrees. Crave2Carve helped me fix the problem and later Fin helped tweak some of the settings to improve the binding fit. I got into the habit of checking and tightening these bolts every time I rode -- glad to see this post.

[yyzcanuck]

I bet some of you will find a screw or two loose.

Fin, I just checked and yep... there are quite a few screws loose here at BomberOnline!

I check our (my wife's and mine) gear on a regular basis. What I find is the screws of our INTEC™ adapters seem to loosen more often than anything else. I'm pretty certain the screw isn't backing out. I believe the adapter material yields because it's softer than the screw head. This was even more evident when I was using socket head cap screws (smaller head diameter than OEM screws).

[trailertrash]

Just as an FYI...

From the TD2 Instruction .PDF

[pebu]

Simple fact is, anyone who does doesn't belong on a snowboard. Especially an alpine snowboard.

Not so much doesn't belong on a snowboard, but should be taught (from the beginning if at all possible) the correct way to do it. And shouldn't be boarding until they know it.

[D-Sub]

well..I did say "those that think that...is too much hassle..."

you're right. The correct foundation is a good idea. Plenty of people are just way too lazy though.

[D-Sub]

better'n "sweet cheeks?"

[Dan]

Also, if your bindings are sized too loose, that can cyclically load your bindings to excess. It should take a full hand or even two to close/open your toe clips.

YES!!

I discovered this myself a few weeks ago at Big MOuntain by tearing up a Catek bail. It was colder than my usual riding temps: about 10 F rather than right around freezing, and my boot shrunk enough to develop some play. By the end of the day, I'd put a crack in the bail...not all the way through, luckily, because I noticed before it completely snapped.

Definitely operator error though - keep those bindings tight!

[chadx]

In two different instances in the past, I had noticed bolts slowly coming lose. One of those times was off the hill. One was on the hill. I was in the bad habit of only checking the bolts once every week (or more). After that, I've made it a habit to check all bolts at least every other day. Usually I find nothing, but occasionally I do.

It's now just become part of normal maintenance. I'd rather spend the few minutes inside the garage and out of the wind doing it with a T handle than waiting and having to do it while fighting the cold and snow with freezing hands and just a little 'L' hex wrench and working on snow/ice packed hex heads. But then, I also do a walk around on my motorcycles and dirtbike before riding them. Much more convenient finding a problem in the garage than along the road or a trail out in the woods.

People just need to learn (like I did) to follow the directions that come with their bindings and do the maintenance. Mechanical 'skills' or not. It's a wrench and bolt. "Make sure they are tight" shouldn't be over too many peoples heads.

[Snowman]

Lets tar and feather Fin. His products stink. Come on, lets get real here. Luckily no injuries were incured. Remeber nothing is infailable and failures do incure weather they be a metal issue with the bolts or lack of rider maintenance. I for one am guilty of not checking my hardware on a regular basis but I have be fortunate to never have a binding break and Im a 200 lb fat ass. Who knows mabey the bindings were set up improperly. I am sorry to hear that it happened and I am positive that Fin will do what ever it take to rectify the problem.

Think Snow

[abakker]

i'm just going to go ahead and say that i check my binding constantly, morning at lunch and at night before riding. maybe a habit i got when i used to ride palmer bx lifts with k2 clickers on a burton board(screws just didn't stay tight).

now i have to ask, isn't the number of breakages in either bombers or cateks significantly lower than the old plastic bindings like burtons?

i met a guy on the chairlift who said he has been through 5 burton toe clips this season and said he keeps a spare in his pocket.

i'd rather check my bindings than carry a toolkit and some replacement parts.

Alex

[EastCoast]

Hi all, speaking as an engineer riding TD1s it seems to me that a simple bit of cheap insurance to ensure your shoulder bolts don't loosen up on you is to use a bit of medium-strength loctite on assembly. With the medium strength you can still get it apart later, but the bolt is much less likely to loosen from the repetative loading and thermal cycling these parts experience. It is true you need to be careful not to get any loctite on the bail to bolt surface, but if you get the newer loctite gel stuff its a bit easier. Perhaps I am missing something here? In any case, I check that all the bolts are tight on my bindings every couple of ride days, takes all of 30 seconds.

Phil.

[bob knox]

Why aren't the bails semi-stiff braided stainless cable instead of bent metal? Every time you bend steel it work hardens and you get residual stresses (post process heat treat helps, but doesn't cure). Cables would conform to every boot shape imaginable (eliminates us ice climbers from taking a hammer to the bails for a tighter fit, and no, I wouldn't do that to plate bindings). Having one cable loop would also eliminate multiple screw failure points. It would take some creative design to get the cable to adjust for boot lengths, but that shouldn't be too tough. It's what I do for a living :D

If anyone has these parts modeled up in 3D CAD, I could run a free Finite Element Analysis in Ansys. Fin's right though. Once those shoulder bolts loosen, ALL the stress directed right at the thread/shaft interface of the bolt which is REALLY bad. I would also look into cold temp Locktite and screw everything tight when the board is literally ice cold. Aluminum contracts like crazy with the temp change from inside to outside.

Bob K.

[Linus]

I'll let Jack, Fin, and others who told me that I let the bolt loose......

Funny thing is that My Suspension Kit came a couple of days before I went out and I install them just the day before the ride. As I always do, I tighted all the screws and bolts. So I don't think the bolt came loose after 3 runs.

Just let you guys know that I wax my board after one full day of riding and I remove my binding when I do so. So checking binding screws after every ride is just a normal every day maintainance for me.

I still can't figure this out yet but, I think I should just replace the bolts after couple years just to be safe. My TD2 is about 3 seasons old so it's definately not new.

Thanks Michelle for the quick response. I still believe in Bomber's product and I've been their loyal customer and will be.....I just wanted to warn everybody to know that it does happen so check your bindings and replace the parts after some years of use.

Btw, the Suspension Kit rocks!!!!!!!!!!!!!!!!!!!!!!

Fin, I'll send the block to you when I get my parts. Thanks

[dano]

I only have a pair of TD1's and don't use them at the moment, but I will sure as hell tighten the freaking bail bolts before I do.

I check my binding screws every few riding days..

Of course this stuff will get loose..all the tempuarture changes and varied loads. It's common sense to most but not all.

I also know that one should usually assume mostl customers are morons and make every attempt to let them know of any potential dangers. I hope the td2 docs don't just say "keep all yer bolts tight" . It should say keep them tight or THIS could happen and show Linus' pic.

What really is scary is some clueless twit buying used bombers on ebay w/ no docs, then having them explode and knocking one of your close friends or relatives into the trees head first. Morons don't always just hurt/kill themselves.

[Derf]

I am in the mechanical engineering field also. I didn't make any calculations, but I agree on the principle that the shoulder bolts need to be tight to work properly.

Bindings are like everything else: they need maintenance, especially if your safety depends on it. Maintenance is a part of life, period. you do maintenance on your body by eating well and going to the doctor when you are sick. You do maintenance on your car,(like my sister in law who didn't know she needed to chainge the oil in her car), you do maintenance on your bike, and so on. Even a computer needs maintenance (in relation to the thread in OT).

People think that because they can use something, they are OK. Lots of people forget the rest. Sometimes you need to know how to do maintenance, sometimes you need courses just to operate something and people won't do it. Sure, you can design something to be foolproof, but it doesn't replace a user who knows what he is doing, even less one that think that he knows what he is doing but in reality doesn't.

BTW, Linus, this is not directed at you, it is a reflection on people in general.

[Neil Gendzwill]

What really is scary is some clueless twit buying used bombers on ebay, having them explode and then knocking one of your close friends or relatives into the trees head first. Morons don't always just hurt/kill themselves.

The clueless twit could be the seller - if the bindings were used with loose bolts but hadn't failed yet, the buyer could be in trouble even if he properly tightened everything.

[Pow]

just tightened everything... I had been riding with a completely loose and freely moving heel block sunday and didnt even realize it! (not as outrageous as you might think... they are set all the way to the outer edges of the inserts so that the heel of the boot pushes the block out and keeps it on) I think i have a curse, for as long as i have been snowboarding my screws seem to always come loose more often than anyone else's on the slopes:(

[pebu]

On my soft setup, with exception of the lean brace which moves alot, none of the screws came lose. Even the mounting screws. On my new alpine board I already lost a screw. I'm sold on tightening every day or every other day or so.

[Linus]

I was hoping to be able to get some of these parts back so I could make a direct comment on this particular event but I feel I should share our conclusions now about this situation.

We have been running this type of interface on the TD line of bindings for over 15 years with great success. The concept behind it is we remove the 90 degree bend found in other bails that can be prone to failure if not bent correctly. We have ten of thousands of these shoulder bolts in service on thousands of pairs of Trench Diggers that have seen (collectively) used hundreds of thousands of days on the hill. And I can tell you with honesty, the percentage of these shoulder bolt failures is EXTREMELY small.

So why do we see a breakage like this even occur? After being able inspect a few of these in person and after seeing hundreds of bindings (all makes) walk through our shop over the past years it comes to one reason, the shoulder bolt was allowed to get loose. A should bolt gets its strength from the tension it is under, if you remove that tension the bolt loses a significant amount of its designed strength. Those shoulder bolts will lift a car in the air if tight but as soon as they are allowed to loosen, it will fail eventually.

A good portion of the people I also question who have had this happen have also admitted they have never checked those bolts or think they did maybe a while back....maybe. I have to admit, it is a unique bolt used only on our bindings and is not thought about a lot. But you still need to add it to your check list on your hardware.

The use of a shoulder bolt under shear is completely acceptable and has been since the design of the wheel, i.e. an axel bolt. The wheels on your car are held on with bolts in shear and works excellent. But if you allow those lugs nuts to become loose, you break a stud off. Keep them tight.

Now I agree alexeyga, you don't want to make things to complicated or people get confused and just don’t bother. But there is a certain level of responsibility by the user to maintain their gear. Carving set-ups inherently have many parts that need to be looked after and that will not change for a long time. Do you check the mounting screws on your binding to your board now and then? If you do, just add these bolts to the same check. I personally check all hardware when ever I do a tune/wax on the board and sometime more then that. To not to this, would be just dangerous and not responsible in my opinion.

We get tons of bindings that come through on boards here at the shop and at demo days. I am now at the point where I have a T-handle or driver near by and I just instinctively check all the bolts. I have lost count how many of these bindings (all makes) have over half their hardware loose. Here is a quick list of some of the "scary" set-ups we have seen over the years. I know there are more and I have always told myself to document these better but here are some samples of what people have the capability to do:

- A guys broke two shoulder bolts in a row with in the same week. I couldn't figure out why it was so chronic so I asked him to send me a picture of the third set-up after he received the parts. In the picture I could see what happened, he was assembling the shoulder bolt with the Lug turned 180 degrees. In other words the counter bore that the shoulder bolt sits into was turned INWARD towards the binding. Of course as you tighten it down the bail would just lock up and not pivot. So the guys figure he would just turn the should bolt out two turns and then the bail would pivot. The poor shoulder bolt would hold on for about a day.

- Another guy called and said he had some serious issues getting his newly acquired TD bindings to fit his mountaineering boots and had to modify them to fit his boot. I said that was strange as they should fit any DIN standard boot, but he insisted they did not fit right. So I had him send me a picture. The guy was new to plate bindings but had experience in mountaineering. He was familiar to crampons that have the clip on the heel of the boot. So the guy was trying to use the toe clip as a heel clip! And in an effort to "force" it to work he went ahead and bent the toe clip so it would sort of work. I told him it was for the toe and sent him new toe clip to try again BEFORE he went on the hill. Which he was ready to do the next day.

- I have seen people use pan-head screws on a counter sunk hole and wonder why they will not stay tight. I have seen people try to use the TD2 lower assembly without an E-ring. I have seen people use only two screws (not all 4) to mount the binding so they can get a wider stance. I have seen other dangerous set-ups that still make me wake up in a cold sweat after all these years. Yikes!

Bottom line, from a breakage standpoint bails are still the number one item to go. And this applies to ALL makes and models of bindings. And even then this number is extremely low from where it used to be at in the industry years ago before strong bindings like the TD2 and the Cateks. Do yourself a favor folks, when you get home tonight, grab your board(s) and a wrench (5mm for you TD users) and check everything on the bindings and while your at it hit your boots as well. I bet some of you will find a screw or two loose. Anyone willing to post here if they do, it would be an interesting poll? Now do this a couple of time a season and you'll be fine and can carve all day with confidence.

Wow.....

I guess there are more idiots than I thought. Especially the guy who tried to use TD2 without E-ring.....seriously, people got to pay attention to the manuals that they get with their product.

[martyagt4]

I'd like to make a comment here. As we know all bolts/studs, what have you, have a certain torque spec that yields the best holding power and strength.

Just making sure something is "tight" is not always enough. If when you go to check that it's tight, and you give it a small turn to just make sure, you are adding that much more stretch to the fastener. Over time this will be just as bad as running a fastener loose.

Not saying anyone should carry a torque wrench with them on the slope. Just an idea as to why one's bolt might fail after making sure it was "tight".

[powell1.8]

Good Point. Should it really take two hands to close the toeclip?