The exact same thing happened to me at the exact same race in the exact stretch of road.
I was on the descent from Hawi (Kona 2017), hit a seam in the pavement and the rear aerobar bolt sheared off.
Aerobars suddenly pitched forward but I was able to get a hand on the base bar and come to a controlled stop from 35 mph.
Bike tech vehicle showed up and helped me get the bar off. Mechanic was amazed as he had just attended a crash further up the hill caused by the same bolt breakage. At the time I did not know it was also a Trek.
I rode the rest of the way back to Kona sitting up, hands on the pursuit bar.

you two are just backdoor bragging.... ;)

---

Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

I've not had a bolt break... but I've found I have to torque them a little past spec to get them to stay tight... if we're talking about the monobar here. I shot a video of it recently as I rebuilt the front end and had forgotten this little detail. I torgue'd it per the spec written right by the bolt and after a 40 mile ride my monobar was almost falling off... finished the ride on my basebar, but it was just about to fall off! Next time I have it apart I'm also going to put some blue thread locker on it... I digress.

The roads are awful around here but it is unsettling if/when the monobar starts getting lose or even worse in your scenario breaks off. Do you have pics of the bolt?

do you have the tilt maxed out? is it only affecting those who use the full tilt up?

like the above poster, i have found over time the bar moves- I didnt realize it till i saw a pic of me side on, just how far my elbows had moved back towards my tummy. I now moved it back out, i have a bit of tilt but not a huge amount like the pic. I torque it up a little bit more than required. Touch wood my bike is 2014 and ridden on the trainer a lot so i cant complain with the movement over time as it has held up, that aside.
On a seperate note i find those bolts around the aerobars and mono really easy to round off

In addition to posting here, you absolutely should report this failure to the CPSC.

---

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
--

Are you using the correct length bolts? I don’t have a Trek, but I made sure to use the absolute longest bolts I possibly could with my aerobar risers. I want as many threads engaged as possible.
Also, you may want to source some stainless steel bolts to help with sweat corrosion from indoor riding.

---

Alex Arman

Strava

^ This. Stainless steel bolts. If you ever see the pros bikes, they all have stainless. I’m not sure why Trek never addressed this

I had one shear off about a year ago. I was able to make it home no problem still riding in aero.

I think its important how you tighten down both screws. Most people will just completely tighten down the rearward screw to the max torque and then move to the front. Personally, I like to evenly tighten both screws a little at a time so the load/stress is shared between the two screws. Tighten one screw a few turns, tighten the other a few turns, rinse/repeat until you get to the desired torque.

---

blog

I haven't had problems with those bolts (other than them occasionally coming loose), but have a consistent problem with my seat post clamp bolts. They've broken 3 times in 4 years, and I weigh 140-145lbs. After the first time, I made sure to use a torque wrench.

I tried using stainless steel bolts but just couldn't get the right fit with them, they'd come loose rather quickly. So now I just carry a spare seat post clamp & bolts with me at all times.

This happened to me twice but Trek replaced whole fork both times.

Blue loctite.

---

Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

Happened to me last year. I hit a bump and thought it had come loose, so headed home on the pursuit bars. When I took it apart I found that the bolt had sheared off.

The bike was just under a year old so they replaced the entire set of bolts on the bars for free, but I don't think that was standard practice. I don't ride the Speed Concept on the trainer.

---

-- Scott

Yes, I was a bit hesitant to use it there, perhaps unnecessarily so. Might have to go back to that idea.

Hi everyone,

I have owned my G2 speed concept for right at a year now and have had a fair amount of issues that occurred to the bike. I don’t really care to get into all the issues but I would like to discuss one that had happened to me during an Ironman race. The rear mono bar cradle bolt broke inside its T-anchor at mile 50 causing complete loss of control and usage of the aero position.

I did successfully finish the bike segment but was caused to ride in the bullhorns for the remainder of the race. We fast forward to the following week during my travels home I decided to contact Trek HQ directly and tell them what issues I had during my race. I was ensured that they had not heard of it before and the bolt breakage was a coincident. I was requested to take the bike to my local Trek dealer and they would have it sent in for inspection.

The result was Trek warrantied all the cockpit bolts and covered the repairs labor to the bike and I went on my way. This in my mind was not an answer to the issue I had and I felt that there was an underlying issue.

So, being the mindset that I have and the industry that I work in I started digging further into the issue and uncovered a lot of other people having the same incidents online with breaking the bolts. This thread is proof of what I found elsewhere, I even found people having accidents while descending (some may be in this forum). I started to become fearful of riding the bike so I contemplated selling a bike that was only 6 months old (at the time). I then decided that I would address the issue in another fashion as the bike was paid for and I simply didn’t owe anything on it.

I made a few sets of custom cradle bolts and started testing them – fast forward to the beginning of February I “searched” for someone that had continual problems and issues with the bolts breaking and reached out to them (Hence my ST account being created then). I sent them a set of bolts and I am proud to say that to date that the individual has had zero failures and has regained confidence in the bike (hopefully they chime in). I was told that they would have a failure every 6 weeks with the OEM bolts.

The bolts are a custom 450 stainless steel with a 180KSI strength – they are designed not to corrode and the strength should ensure that they never have a separation failure.

So, what says the ST community – is there interest in me manufacturing more of these bolts and if so how much interest? I can’t tell the pricing on them yet as it all depends on how many is made, it goes without saying that I was willing to go to great lengths not to get hurt and I suspect others feel the same way. It is a great bike and fits a lot of people but as anything IMO a minor manufacturing defect of material/quality for this design and clamping system.

Some photos of these beauty’s;

I think it is very cool that you made those new bolts. But....if you sell them, and one -happens- to break, and someone gets hurt, are you setting yourself up for a big lawsuit?

I’m Damiens friend. If you have another set shoot me a pm and I’ll buy them. I have yet to have a failure as I don’t ride my tt bike often but I don’t want to chance things. The courses we do are rough, and probably really bad after this winter

...Seems like trek isn't too worried about the weaker bolts they are providing.

i see this 'lawsuit' logic from people a fair bit. Does anyone here know of a person that 'acutally' sued a bike manufacturer?(Genuine question out of curiosity)

That sounds awesome, but besides the liability issues that one poster brought up, does Trek warranty get affected in any way? This is great of you to do this and if I had a SC I'd jump all over it.

---

Gary Geiger
http://www.geigerphoto.com Professional photographer

TEAM KiWAMi NORTH AMERICA http://www.kiwamitri.com, Rudy Project http://www.rudyprojectusa.com, GU https://guenergy.com/shop/ ; Salming World Ambassador; https://www.shopsalming.com

I'd absolutely buy a couple of sets from you. And per my post above, I'd buy some for the seat post clamp bolts as well, if they could be made available.

As with the other recent posts, I'd buy a set too if I were riding a gen2 SC (I own a gen1). I was just bringing up the point for food for thought...

To answer your question - yes, bike companies get sued! (google search it) lol. As for Trek not caring, maybe not, but they have deep pockets, liability insurance, and lawyers. :)

Interesting.

I’ve had my bike for about a year now and have maybe 3k miles outside on crappy Texas roads with nonstop chipseal, pot holes, etc.

Bolts haven’t come loose and are visibly in mint condition.

Granted my anecdote isn’t data.

Could there have been a batch with substandard metal that got into the pool?

I’d be interested.

Hmm. It seems worth stating the obvious -- that the gen 2 SC has been around a long while now, there are tons of people riding them, and aerobars are not failing at a high enough rate for anyone to notice before now. (Mine has 5000mi on it and I've changed the front end around a lot and no issues at any time.) I'm going to guess that this problem is limited to a pretty narrow set of circumstances. It seems to involve tilting the bars up near their limit, but I'm also guessing that somehow the rider position has to put significant downward weight on the extensions to stress the rear bolt. For example, I almost always pull up on the extensions to help generate power, so can't really imagine the rear bolt failing for me. Some installation details, such as order of bolt tightening, torque used, etc may also matter. It does seem like it would be worth Trek strengthening that bolt as much as possible. You guys should try hard to contact someone at Trek with some authority. It's too bad Carl isn't still around.

Never had an issue in 3 years and I use close to max tilt. I torque the bolts with my torque wrench, set the limit screw and that's it. I've taken my front end apart and used different degrees of tilt over time.

---

What's your CdA?