Riding to work this morning my left crank FALLS OFF!

I was utterly stunned. A crank falls off?

I've got a one month old Seven Sola Steel and I'm trying to put some miles on it to break it in because I'm doing a portion of the Continental Divide this summer on it. Well I sure "broke" it in. The crank falls off in the middle of a turn. It's in the street and I'm dodging cars trying to retrieve it.

The long and short of it is the threads on the inside of the crank stripped. It's one of those ill fated '04 XT integrated BB-crank "innovations". I know what "integrated" means now-- when one tiny part fails, they all fail together. When the crank comes off, the whole crankring set and BB slide right out. I'm shoving this thing back in with my right foot and shaking the left crank off while avoiding cars. Jesus! At least I could walk the rest of the way. I would have HATED for this to happen in the middle of Montana. Still, there's this great shame *pushing* a $4000 bike.

Between the Dual Control shifters/levers and this bottom bracket from hell, what's there to like from XT? I've never had anything nicer than LX in my life nor have ever had a problem with Shimano equipment. Happiness is having a good time using inexpensive (and well designed) toys. I'm not happy. Do nice bikes break more often? It just doesn't seem rational but it appears to me nicer parts have greater expectations placed upon them and their design often tries to overcome conflicting needs i.e. lightweight but strong.

(On a side note, my LBS where I got my custom nightmare is replacing the whole unit with a different bottom bracket and an '03 XT crankset and sending this thing back to Shimano. It's one of those "octalinks". I just don't trust the thing and I'm nobody's guinea pig. I'm replacing the shifter/lever pods from my own pocket since they aren't my preference.)

Chuckie

Do you check your parts and bolts. I check after almost every hard ride and once a week for things to loosen...especially with my suspension bike.

I think you are one of the first people I have heard having a problem with the bb/crank...thats too bad...

Like you said, I have more of an expectation for nice parts. I expect them to work flawlessly or I consider them broken. Constrast this to low level stuff that as long as it stays together and shifts sometimes or whatever I am happy.

As with a lot of things, I try to stick with tried and true technology.

Nice bike by the way. A Seven MTB and road bike are my dream bikes.

A see...I guess I have a different view. More epensive parts are not always as durable. I find the upper echelon xc parts are more 'light' oriented instead of strength oriented.

Not that in this situation that is true.

My 820 held up to stuff that flattened a lot of people and places people busted chains. Example: urban assault on downtown Cleveland, climbing a hill, a full XTR, spandex clad rider busted a new chain climbing the same hill that I was beating him up! Another example, after jumping a 3-4 foot ledge, a rider on a dirt jumper got a flat tire, and my bike held up fine. I really think that the Trek 820 is more trail worthy than many think. Maybe the lower end components, since they are steel, are tougher...just a theory though. I'm out there for fun, I don't need a race bike. With the accessories and upgrades I've put on the 820, its a durable(HEAVY) ride. I look forward to a summer of pounding on it, and another and another.

Oh, and I am a rather robust rider(210), so weight takes a back seat to toughness

You might want to check your frame for cracks trekkie. A good bike will have parts that will give in way before the frame will. I'm not saying that your 820 is a depot store bike, but the parts spec is very close to that. Plus you have to think how old that chain was(It mayhave looked new, but the person could keep the chain looking new.) Or it was a defective chain, no way to control that, and what psi the dirt jumper was running could have been low. You got to put all of those equations together before assuming something like that.

Back to the topic, do what maelstrom said, check bolts before and after each ride.

You espically have to check the 04 XT cranks. the crankarms seem to be bolted on to the bb.

I always inspect my bike after a ride, along with a complete cleaning and lube and bolt check. You can never be too careful...

i don't know

i am just waiting for my carbon fiber steer tube and crown to snap on my sid worldcup....so far so good though
when i bought the bike the dudes at the shop were like...."this is really a race day fork"....what does that mean???

on the other hand...for the first time in 12 years of riding i broke the free hub mid ride on my hugi/517's...which i thought were decent wheels.

i think some of the very light "race stuff" is built to "burn bright but not long"

$5k on a bike SHOULD give you a little peace of mind...oh well

I'm with trekkie on this one. I have a 1994 trek 820 that I'm finally replacing this year. Not because it's broken, but because I grew out of it a few years ago (still kept it for short commuting during college). The last few years I've kept it outside during for long periods of time and not given it a second thought. The chain rusted but otherwise the bike keeps chugging along. Mind you this bike was my only form of transportation for many years. It must have thousands of miles on it. Some cheap bikes will perform forever.

It means that you put it on for race day, because the $1000 CF fork couldn't withstand everyday riding.

This coming from the guy doing urban on an 820

I like this saying:

Cheap, Light, Strong........ Pick two

I saw this on a guys signature at a different forum. I think it is pretty accurate.....

Dean

There is a big difference between race reliability and tour reliability. For racing, it should work really well, but if it breaks, you are out of the race anyway. On a tour you want what engineers call "graceful degradation". If it fails, you can still ride the bike, even if you lose some speed or gears or indexing convenience.
Its really hard to find modern tour-worthy components, that is why so many touring bikes look retro.

Truer words have not been spoken. I like cheap and strong, so maybe i didn't do too badly with my 820.

I completely agree. I too like cheap and strong. Hell, I'll even take moderately expensive and strong as long as it works-- can't stand when something breaks from ordinary use. I *am* more understanding when it's cheap, though.

Chuckie

Mmm... Shimano. King of building you sh1t you didn't ask for. You know.. they could build you a bike that would never break in a lifetime of use. The only drawback would be that it would weigh 400 pounds.

thanks for clearing that up chief!

...but seriously...the fork has been bullet proof!....i mean i am not reagulary hucking 15 footers but south mountain is brutal!

I'll take light and strong, personally, but I'm a little girl trying to drop the boys. Anyway, it sucks about your crankarm; at least they're going to warranty it. I don't know what I'd do if out of the blue mine fell off. At least you weren't 15 miles from the trailhead, I guess. I refuse to try the new shifters; it seems like more stuff to go wrong. If it works, I don't mess with it.

Truthfully after working on, using, and now owning the new STI XT shifters Rapidfire feels like a trip to the Paleozoic era... I've had my XT's apart and think they are at least as easy, if not easier to work on than the old RF's since the shifter mechanisms are more readily accessible by simply removing the top cover... no need to take them off the bars even. Lots of crashes and still going... just like any brake lever, don't tighten the shifter onto the bar so much that it doesn't give under an impact... actually mine took the entire force of an impact coming down about 4ft onto concrete at speed... just a bit scratched.

Seely, I'm more concerned with my riding style, and braking/misshifting causing a crash. The concept works great on my road bike, but the technology on my mtb causes a little concern. Of course, I'm still running v-brakes for the same reason.

I believe that was tomac. And it is very true. Personally I am a cheap/strong guy

I've had the crank arm fall off 2 different DH bikes I own over the years.... The reason? They simply came loose and the bolt fell out. The 1st time I had to hikeAbike for about 3 miles back out, but the 2nd time I was able to locate the bolt, but didn't have an allen wrench to fully tighten it. I had to stop about every 100 yds. & tighten it the best I could with my keys... I now carry a small asortment of allen wrenches.