TD2 Shoulder Bolt Failure

[Linus]

I was having a great day today. Combination of very little amount of people on the slopes with not too cold weather, I was happy. :-) As I always do, I went to the steep and started euro carving. After about 3 runs, I cliped in and start with my heelside and went for my toeside. Certainly, my front foot was on the slope and my board flew up in the air. Since I was euro carving, I didn't take any impact from falling but, my ankle was sore. I wasn't really hurt so I took my time to look what's wrong. And guess what? The shoulder bolt sheared off, spring was gone and bolt head was missing from my TD2 As you can see from the picture, the remaining piece of the bolt is still there.

FWIW, I'm 5'11" 175lbs. and people tell me I'm very aggressive since I use a lot of body rotation.

I think I heard this happened to the other member of this forum and I'm now a bit concerned about the whole thing. Is this just a bad batch of bolts making problems or else?

[MR. JOHN DEERE !]

get our fat ass's out of bed, catch the first chair upto the top. its going to be a perfect day! 8" fresh snow friday. in the single digits for two days in a row, and the whole mtn was curdoroy. my buddy goes to put his rear foot in and the screw snapped. hes used his td'2s maybe 10 times and they have broken 3 times. good stuff. ive had bails break a handful of times but not 1 out of 3 days. he was bulls@&%. it was along walk down. but i had a great day, so f@%* em! lol

[Jack M]

Any bolt will fail if it is not torqued properly. When was the last time you checked it for tightness?

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.

[alexeyga]

Is it me or somebody else also thinks that it's just not a good idea to use rather small screws as a shaft? Bolts/screws are meant to be loaded longitudinally, not tangentially... There is a whole bunch of mechanical engineering geeks around here, speak up people!!!

I don't want to start another Catek VS Bomber flame, but keeping in mind that it's the 2nd thread about TD2 shoulder screws for the last couple of weeks.. I tend to think that Catek's stupid-simple bail is somewhat safer...

[Michelle]

I received an email from this customer, and we are taking care of him today. Whatever the issue was (based on you engineering minds) I will have him back on the slopes before the weekend.

[D.T.]

I don't want to start another Catek VS Bomber flame, but keeping in mind that it's the 2nd thread about TD2 shoulder screws for the last couple of weeks.. I tend to think that Catek's stupid-simple bail is somewhat safer...

Here is you answer:

Any bolt will fail if it is not torqued properly. When was the last time you checked it for tightness?

Also, if you bindings are sized too loose, that can cyclically load your bindings to excess.

Post #39 in this thread discusses the issue as well.

The problem boils down to people not taking care of their gear! CHECK YOUR GEAR PEOPLE!!! Do it regularly! If you are obsessive, do it everyday before you ride. At minimum, do it every couple of days. If you ride aggressively do it more often. If you are a bigger person, do it more often. Replace your all fasteners every couple of years to minimize the possibilities of long-term problems, i.e. fatigue failures.

How often do you tune your boards? How often do you check your bindings? How do the numbers compare? If the number of times you tune greatly out numbers how often you check you hardware, you should rethink your maintenance habits.

[alexeyga]

Here is you answer:

Any bolt will fail if it is not torqued properly. When was the last time you checked it for tightness?

Try explaining it to the next guy who'll end up in a hospital because these screws have failed... These bails have to be bulletproof and should not require an airplane-like checklist before being used, that's just poor engineering (or over-engineering)! Not everyone is mechanically-inclined around here....

Linus,

Is it the rear or the front one which failed?

[pebu]

It's easy to blame engineers. Everybody always does. And sometimes it is the engineers fault. But in cases like these the engineer is in a lose lose situation. The package size of course has to be small. But there are so many other things that need to be taken account for. If the package got too big then consumers wouldn't like it. If it breaks consumers don't like it. It's a trade-off. The lesser of two evils, so to speak.

Not to mention, you're flyin down the hill at 40 or 50+ mph on a piece of wood! (Depending on your ride of course.) This is at least as dangerous as an airplane, so why shouldn't there be a checklist? I think it's a fair price to pay. If you're not satisfied then talk with an engineer and see if the two of you can come up with a custom product that will make you happy.

[Jack M]

Alexey, do you wait for a red light to shine on your dashboard before you change your oil? Do you wait to hear a grinding noise before taking your car in to have the brakes inspected?

Take a look around. The few people breaking these things are the exceptions. It's user error.

[alexeyga]

Jack,

I see you point, I totally agree, but having used a product which doesn't leave any room for such "user's errors" makes me really anxious...

[alexeyga]

It's easy to blame engineers. Everybody always does. And sometimes it is the engineers fault. But in cases like these the engineer is in a lose lose situation. The package size of course has to be small. But there are so many other things that need to be taken account for. If the package got too big then consumers wouldn't like it. If it breaks consumers don't like it. It's a trade-off. The lesser of two evils, so to speak.

Being on engineering position I know a bit too well what you mean... But let's get back to these bails, the idea is beautiful, however the fact that it only takes one loose screw to f#$k things up doesn't inspire any confidence, does it?

Fin,

What prevented you from making real shoulders on the sole blocks? Or making shoulder bolts to go deeper into the sole blocks?

Is it me or these shoulder bolts take nothing to snap if only a bit loose?

[D.T.]

the fact that it only takes one loose screw to f#$k things up doesn't inspire any confidence, does it?

alexey, the problem was not simply "one loose screw". It was one screw left loose for a prolonged period of time without the proper preventative maintenance that caused the problem. There is a big difference.

[fin]

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.

[D-Sub]

last night playing pool I was angry and smacked my cue against a barstool. The shaft broke.

!#$!@#$!@# Viking Cues better resolve this issue or I will sue them!

Alexey

stop and think for a second. You stated above that asking users to tighten a few screws/bolts regularly is somehow expecting too much.

you can't possibly think that is logical.

[alexeyga]

stop and think for a second. You stated above that asking users to tighten a few screws/bolts regularly is somehow expecting too much.

For some people making a difference between hex and Phillips screw heads is "too much", so how can you expect any regular maintenance from them?

[D-Sub]

For some people making a difference between hex and Phillips screw heads is "too much", so how can you expect any regular maintenance from them?

Bro...you're gonna make me lose my temper. You are making some incredibly irresponsible inferences right now.

Bomber supplies the wrench that fits every single bolt on the binding. They specifically had the mounting bolts custom made so that one wrench would fit everything.

If someone is that !#$!@#$ lazy, I couldnt care less what happens to them.

[Bullwings]

For some people making a difference between hex and Phillips screw heads is "too much", so how can you expect any regular maintenance from them?

this is sounding a lot like

"OMG, i spilled coffee on my lap and got burned. that damned McDonalds makes their coffee too hot, they need warning labeles."

Or

"All that crap in McDonalds food has given me heart disease, they need to fix that..."

how about, your fatass not eat mcdonalds every day and watch Supersize Me. and what did your dumbass think coffee was gonna be filled with, icecubes?

this is like asking your parents to hold your hand till your 40 everytime you cross teh street.

edit: i'm not attacking you either alexeyga, just to make that clear, since internet is touchy like that. just a certain level of responsibility needs to be accepted by the user/consumer

[alexeyga]

Bro...you're gonna make me lose my temper. You are making some incredibly irresponsible inferences right now.

I might just keep tickling you for the sake of it... :D People are lazy, and the biggest mistake you can make is judge everybody taking your-self as a reference... I guess i'd better shut up, it's getting too personal... These who care to stop and think, had enough in this thread to think about...

[D-Sub]

Again I say, if someone is that stupid to where the incredibly minor amount of maintenance required by TD2 bindings is too much, then natural selection will soon take control.

[Mike T]

Thanks for the post Fin! After seeing a buddy break a couple of bolts my stomach was queasy even though my brain told me that I had nothing to worry about since I am obsessive about setting my gear up properly and checking it often. The queasiness goes away when I know specifically what to look for.

In any case, I was changing a spring on my wife's TD2s the other night (I had damaged the old spring when converting her step-ins to standards... with a little help my my 4yo who was 'helping'...) and reassembled it with the lug bore facing the wrong way as Fin describes. REALLY easy to see that you've done this:

1) When you tighten it, no spring-action on the bail

2) The bolt sticks out of the lug, rather that being flush with it

If you ever find a bail not springing nicely when you have it cranked down tight, it means you probably have a lug facing the wrong direction *or* you threaded the bail into the lug unevenly, i.e., a different number of turns on each end. I can imagine that the latter situation would cause some fatigue too although probably a lot slower than the reverse lug situation.

PLEASE check your gear and don't rush when setting it up! Also, I know a lot has been said about not using T-handle wrenches to attach discs to decks, for fear of over-torquing and ruining inserts, but I personally won't use anything else to assemble the binding parts together.

On that note, if you use a short T-handle to fine-tune your bails while the binding is mounted to the board, you may find that the board gets in the way of tightening it properly. Some nice, high-quality *long handle* T-wrenches are available here:

http://www.wihatools.com/334serie.htm

(I personally fasten disk to board using left hand, everything else with right... seems to get me the right torque... YMMV. The long handles give you a TON of power!)

[Jack M]

For some people making a difference between hex and Phillips screw heads is "too much", so how can you expect any regular maintenance from them?

I personally am not as concerned with these people's safety as I am about them polluting the gene pool.

[D-Sub]

I personally am not as concerned with these people's safety as I am about them polluting the gene pool.

ditto.

sad thing is...the Nanny State is concerned with their "safety" and is perfectly happy allowing them to sue upstanding businessmen. Anything specific come to mind?

If you can't remember to tighten bolts, you might want to consider agoraphobia. Never have to worry about getting injured.

but wait...that garbage disposal! Coffee maker! MICROOOWAAAAVE!!!!!

[tex1230]

:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

[D-Sub]

man I just fell off the toilet. I was sitting there doing my business, and all of a sudden CRACK and Im on the ground.

looked, and the damn bolts that hold it down sheared off. The toilet had been shifting around for months, but I figured it would resolve itself eventually. I mean...who wants to get down underneath a nasty toilet to check if bolts are tight?

Im writing my congressman right now. Well...after I get all this :confused: off me.

[yyzcanuck]

The toilet had been shifting around for months, but I figured it would resolve itself eventually.

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