I had an aluminum frame crack on me after ~11 years of use. the manufacturer used to put a crimp in the right seat stay down by the dropout so the chain would have room to pass when it was in the smallest cog. the frame cracked there. thinking back to my unexplained shifting problems while climbing, I probably rode it partially cracked for a few months before discovering it. Frame was replaced free of charge by the manufacturer, no questions asked.
Two friends of mine have cracked the chainstays on their steel bikes, same frame type, major manufacturer. Again, both replaced free of charge.
Other than the first-generation carbon tube/aluminum lug frames, no
From personal experience:
-I broke two carbon/aluminum forks. One was a first-generation one (from the AL frame that cracked, purchased in ~1994). the fork blades were carbon tubes epoxied to an aluminum crown. after ~8 years I was cleaning the bike and noticed the fork blades could be wiggled back and forth freely, i.e. the glue joint had failed and was only being held in place by the bumps on the aluminum that the carbon was wraped around. Not good. the second fork sheered off at the steerer-tube to crown junction while I was riding it (luckily i was going uphill at the time and was not seriously injured), The fork was carbon blades and crown with a carbon steerer tube, stuck together using a !!!Cast Aluminum!!! crown race seat. Looking at it after it sheered, it was obvious that there was a void in the casting of the aluminum junction piece that acted as a stress riser that started cracking. The manufacturer insisted that their fork couldn’t have failed, and I must have installed it incorrectly. Coincidently, they no longer manufacture this fork and outsource their forks to Reynolds.
-I sheered an aluminum crank in half while coming off of a stoplight. it was one of the mid-90’s CNC’ed models that was all lightweight and shiny.
-I ripped an aluminum stem in half just in front of the weld on the quill. this resulted in a face plant in front of a bus in Boulder. Luckily the bus stopped and gave me a free ride home. A replacement stem from the manufacturer cracked in the same place. I told them to keep their next replacement and bought another model.
-I saw my friend rip his bullhorn bar (aluminum) in half next to the aerobar clamp the day before Ironman canada a few years ago.
On a side note, every single one of these failures advertised itself prior to the actual breaking of the component with unexplained creaks and noises that didn’t go away with tightening the bottom bracket, etc. If you have a creak that you can’t identify, or a funny feeling while steering, etc. find out where it is coming from!! it could save your skin.
sort of - I mean, non of the above parts would have failed if they hadn’t been ridden on, but I am confident that poor product design was the root cause of all of them.
other than the time I rode off the side of my rollers?
I have worked in a shop for two years. I haven’t seen a whole heck of a lot of failures, but here’s what I’ve got.
Frames- I have seen cracked frames on steel, aluminum, titanium, and carbon. A couple examples offhand:
Late 90’s steel frame, crack from bottle cage bosses, slowly grew through the down tube, frame warranted.
1980’s ti mtb frame ridden as a commuter. Crack in the bottom of the bottom bracket shell. Ended up being repaired by a local race car builder (it’s great living in Indy!)
Late 90’s carbon road bike, cracked/fraying chainstays where the stays meet the bottom bracket “lug” (both carbon). Warranted by manufactuerer.
Late 90’s aluminum mountain bike, cracked at weld joining bb shell to seat tube. Big rider, ~230 lbs. This is the only frame failure of the 4 mentioned that I could see as possibly being due to fatigue.
Components- I have seen a couple cracked stem face plates, but no stem bodies. The only broken carbon bars I have seen are from crashes. Similar to Tom, I’m not a huge fan of carbon bars. I have seen some slip in the stem clamp. Most are not aerobar compatible. I have seen several failed carbon seat posts. I personally had two be damaged from slipping down into the frame (seat binder was definitely tight enough, and NO grease on post). I have also seen them fail at the clamp- typically an aluminum clamp is pressed or bonded to the carbon shaft. I only use Thomson aluminum posts now.
Trainer damage… never seen it.
I agree with several others here- the frame material doesn’t affect the quality of a product or its fatigue life (and the engineers will give you numbers about aluminum having a short life and yadda yadda… you won’t “wear out” your frame). The more important thing is the build quality, experience of the manufacturer, and the processes they use. There are high quality and low quality frames and components made from all materials.
I had an aluminum Douglas frame from Colorado Cyclist. It had carbon seat and chain stays. I rode it on my trainer, then during the next ride I noticed my back brakes were rubbing. I thought it was the rear quick release sliding.
When I bent down to tighten the rear quick release, I noticed that the carbon chain stay, drive side, separated from the aluminum lug. I would guess it happened from the stress of that lug being held in the trainer and the bike moving side to side.
Colorado Cyclist took the bike back on warranty and even bumped me up to a ti frame with a five year warranty.
The great thing about mid to high end bike gear thesde days is that if you take good care of it, it will last for years. The quality is extraordinarily high right across the board. Yes there is the odd lemon out there.
Other than the obvious parts that get the most wear and tear - chains, cassettes, pedal cleats, tires - that do need to be replced periodically, if you take good care of your bike, it could last year 5 - 10 years with little or no problem.
Yikes… you don’t take your group ride on this road, do you?
Two lane road, traffic, NO shoulder AND a bridge!!! I don’t think it could be more unsafe…perhaps throw in a few semis, school buses and alligators jumping out of the bushes.
“…if you take good care of your bike, it could last year 5 - 10 years with little or no problem…”
Not surprising – the materials used to make bikes are also used to make airplanes, spacecraft, armored vehicles, and America’s Cup yachts. Kinda what I was thinking when I wrote up the questions – but I had to ask anyway. Every now and then (not vary often) there’ll be a small aside about how parts or bikes made of will have a shorter lifespan, and I wonder where they get their information. Bottom line is that it’s not the materials that fail – failures happen due to design flaws, manufacturing defects, or abuse.
Surprised about the carbon fiber seatposts and handlebars, though.
Trainers: I don’t doubt that some have had bikes come apart on the trainer – but I don’t buy that the trainer was the cause. If the bike frame failed on the trainer, then it would have failed on the road, too. The trainer is not a closed system, because the energy of the pedal stroke still goes out through the rotation of the wheel. The bike frame has to flex just as much on the road as on the trainer – but you can see it better on the trainer, and that’s what freaks people out.
I figure it this way, I can push 650+ lbs with my legs in the weight room, that would be about 325lbs each, take that - add my body weight, figure in the leverage from 175mm and the extra from the solid sole in the shoe…I bet 600lbs of force at the BB is about right…who knows, I may be wrong.
Not an owner, but I have ridden bikes for a very long time.
I have only seen frames fail at the joints. I have had two frames fail at the joints, and it was always corrosion. That being said, eventually, frames will fail at the joints.
Unless there is a big, fat, ugly void, a carbon frame will not fail from fatigue. I test and test my home-built carbon items, and they usually fail at either:
a) places that do not have enough material
b) places that do not have enough epoxy holding the plies together. I actually had a big, fat void in one of my very first lay-up ever. It was silicone contamination. Please note that you would rarely find that in a mass-produced bike frame.
I have seen these items fail from all materials: ti stems, ti bottom bracket spindles, steel stems, aluminium stems, aluminium handlebars, carbon stems, handlebars. Usually they fail by either:
a) not heeding weight limits
b) not following manufacturer torque ratings
c) not properly maintaining or replacing them at the right intervals
d) using a stupid light material in it’s first generation
When I rode 20,000 miles per year, you bet I replaced handlebars and stems regularly. You can’t pay me enough to ride a carbon road bar, unless it is a schmolke.
And lastly- don’t buy a stupid-light item in it’s first run. You would be their test-mule.
I have had one broken-in-half frame. It was broken in a race. I think only crashes would cause a broken-in-half frame.
Maybe, and I say maybe you may have used a few more cycles of fatigue from trainer use. But I have yet to see a frame fail from the trainer that would not have failed on the road.
It’s odd that I noticed this thread yesterday, and then last night experienced my first serious equipment breakage.
I was accelerating out of an intersection, going straight and on green, when my handlebars broke in half. Aluminum. They just ripped in half at the stem.
I purchased them about 6 years ago, used. So no complaints. I got my money’s worth.
Oh, after a serious WTF moment I coasted to the sidewalk, dismounted, and walked it about 4 miles back to the house. Luckily had just left home for evening errands and hadn’t made it too far.
Hit the LBS last night, bought new bars, and swapped them out at home. I had fresh bar tape on by 11pm, and back on the road for my morning commute.
Actually, if you look inside a Speedplay X pedal, the spindle goes nearly all the way through to the grease port screw on the end. So, there is very little torque on the bearings and the load is nearly all taken up by the spindle. I haven’t cracked open a Time pedal, but it looks like the bearing is the only thing holding the pedal body onto the crank interface, i.e. no axle…I really hope I’m wrong about that, though, because the amount of torque that the bearings would see would be orders of magnitude bigger than in the Speedplay and would easily be the main failure point. They need that huge bearing next to the crank arm because that thing is seeing torques in all kinds of directions instead of just perpendicular to the axle…a bearing the size of the Speedplay bearings in that situation would be a disaster waiting to happen…maybe that’s why the Time bearings have gotten bigger and bigger through the years? As an engineer, I would trust my life to a solid piece of metal long before I would trust it to a bearing…even one from a long-standing manufacturer like Time.
I would say, don’t run from a weight limit, just pay attention to it and know that if you’re a rider who’s big on torque, you might be pushing the limits. If you see a weight limit, that at least means that someone’s been doing some testing and knows the limits of the product, eh? That being said, I once heard a bridge designer say something to the effect of, “Anyone can build a bridge to hold a certain weight. It takes an artist to build one that barely holds it using the smallest amount of the lightest materials.” I think bike/component manufacturers take that sentiment to a whole other level, especially considering that, other than in places like Tacoma Narrows, bridges see a much more static load than pretty much anything on a bike.
You can’t push any more than your body weight, except what you are pulling with the other foot. Hamstrings actually generate relatively little force on the upstroke so I would be surprised if you are applying any more than 200 pounds force at any given point in the pedal stroke.
600 pounds on a 175 mm crank would be 344 foot-pounds of torque. Most cars can’t generate that, much less people.
but drivers not as scary as there in your place.