Originally Posted by
pdlamb
Perhaps we need to consider what kind of "tour" we're discussion? On Tourist's point, that remote place looks like the place you'd be happy to have an extra 3-10 pounds of weight on the bike to handle the stresses without breaking. Many of the "broke a frame" accounts I've read have been people on extended tours over remote roads for months on end. And like mev's and BobG's examples, it's possible the long desired frame life is frequently met or exceeded on that kind of long trip, typically with a heavy load. Perhaps a loaded touring frame has similar lifetime to an unloaded frame that's not designed, built, and used for loaded touring, but that's just speculation. And does a loaded touring bike use up some of its lifetime if used for commuting?
You seem to be assuming that there is a defined lifetime for a bicycle frame. What would you estimate is that “lifetime”? I have tracked mileage on my bicycles since 1989. I have yet to see a mileage that defines what a “lifetime” for
all bicycles might be. Some individual bikes have had short lifetimes and others have yet to find the failure point. Of the bikes that have failed me…I won’t include the one where I caused the break…the Miyata Ridge Runner (1983) I finally trashed after it had an estimated 3000 miles on it. The Rock Combo failed after 3800 miles. Both of those are steel. The (supposedly) inferior aluminum Specialized Stumpjumper lasted 6600 miles. I have a T800 (retired right now but still very rideable) that has 9800 loaded touring miles on it. I also have a Salsa Las Cruces (also retired but rideable) that has 22000 miles on it with the original carbon fork. Based on my experience with broken frames, I should have
less trust in the supposedly stronger steel frames.
To be fair, I did have a steel Specialized Rockhopper that replaced the Rock Combo that had 9800 hard off-road miles on it.
I don’t currently have any steel bikes. That’s not because I think they are weak but I do think that they are heavy. Aluminum has served me very well…as have some of my steel bikes. Aluminum is strong enough for my weight, size, and loads I carry on tour. I don’t need the extra weight of steel to avoid any breakage.
Quality escapes should include those cases where process variability exceeds minimum design thresholds; e.g., ordinary statistical variation in a weld or heat treatment for a dropout will occasionally result in a weld or a dropout that will fail in normal use, and manufacturing quality should be designed and implemented to catch those cases. But, as Capt. Murphy found, it doesn't always work that way. That leaves ordinary consumers and bike tourists to guess how we should plan for, or plan to ignore, the potential for our individual frame to break.
You keep making mountains out of mole hills. Quality control in our age is far superior to what it was 40 years ago. Frame breakage from frames that have escaped quality control is still a very rare event. Frame breakage in general is a very rare event.
Speaking of statistics, I'm not sure whether I should believe this guy:
Or this guy:
Both of those statements are in agreement. They both address the rarity of events. Tossing 50 heads in a row would be a rare event. Breaking a frame is a rare event. Your 1% failure rate would mean that between 150,000 and 200,000 bicycles break per year (15 to 20 million bikes are sold each year). There would be far more reports of broken frames on the Bike Forums than there are. My 0.0001% failure rate is only 20 bikes fail per year. Mine estimate is probably too low but I would be very surprised if frame breakage per year topped 1000 across the world per year.
Either way, my gut would need a Costco size bottle of Tums to be as calm as his gut is about the likelihood of a quality escape on a given bike frame on an extended ride.
If you are that worried about frame breakage, perhaps you should just stay home. Even with 4 frame failures under my belt, I’m not concerned enough about frame breakage to even give it a passing thought while on tour…even while riding an aspoloding aluminum bike.