Just had a quite spectacular crash on the road bike. Was out of the saddle, putting some power down on the road bike - when inexplicably my crank arm detaches leaving my left ankle twisted, my nut either side of the top tube and a full over the bars in front of a load of commuters. Smashed my helmet (wear one kids!), iphone glass looks like a snowglobe, Evoc back pack shredded and ankle has come up like a watermelon.
To rub salt in a passing BMW driver ran my glasses over as she rubber necked me laying in the road. Not my finest commute.
I get the feeling that crash should probably have hurt more than it did so am thankful for that. But - The bike is quite new....had it a month of so on the RTW scheme and everything seemsed to be in order. There was no indication the crank arm was loose before it failed in such dramatic fashion. Am going to take a proper look later on - Not had a chance to inspect the bike yet as needed to get to work.
I accept liability for my own crashes, where I run out of skill, or because I am being a strava pillock. I'm not one of these people that looks to point the finger.
Question though - brand new bike with not many miles. Either the crank arm thread is faulty, or has been installed incorrectly by the shop. I've wrecked gear that is going to cost me a good few hundred to replace through no fault of my own. Worth raising with the shop?
mccraque - MemberQuestion though - brand new bike with not many miles. Either the crank arm thread is faulty, or has been installed incorrectly by the shop.
Or it just came loose afterwards. It's standard practice to do a nuts-n-bolts check after a few rides, bike shops often offer it for free- like Halfords offer a 6 week service for all new bikes. Manuals tend to include recommended service intervals (Giant's says to check before every ride for example).
Hope you're ok. I wonder if some imbalance was caused by you only having one testicle?
Hard to say without knowing what failed. Have a read of this: http://singletrackworld.com/forum/topic/cyclist-wins-1500-in-faulty-seatpost-case
You have my sympathy for the crash and the resulting damage.
Had you checked the crank at all since getting the bike?
They tend not to come off without a period of being increasingly loose first. Which type of crank arm attachment is it?
I had a very similar crash - although on quiet country lanes rather than in commuter traffic - when my chain came off whilst putting in some serious power. Cracked helmet here too but biggest casualty was pride.
I'm conscious my anecdote goes no way to answer your question, but Northwind's comments should be borne in mind.
there was absolutely no indication that anything was loose. I do check my bikes regularly - am a bit OCD with any type of play, be it cranks, QRs or whatever. so they all get a regular once over. Especially on new bikes as I know things work loose.
Crank arm was def the cause of the crash - not post event. I thought the chain had snapped - but it hadn't. Was the arm flying from the bike.
"Check before every ride" is stupid lawyerese disclaimer bollocks and no court would take it seriously. Properly designed fasteners shouldn't come loose that quickly. That said, it seems odd to lose a crank without noticing it coming loose. Unless perhaps the retaining bolt was missing completely.
I don't think the new HTII type cranks give as much warning of impending doom as the old square taper. I have a few riding friends who're not complete mechanical reprobates have had the non drive side come off mid ride. When I give my own bike a check up the non drive side pinch bolts usually need adjusting after a month or two's use. The old type used to feel a bit loose and you could sense the knocking.
Hard to tell. Post-new bike purchase you have a service (some shops sell bikes with these with 1month etc service) to recheck all tight/readjust etc.
How many rides have you done on the bike? If your an enthusiastic cyclist don't forget 'our' miles/usage in just a month may be 6months use to a normal person.
I've had a saint non-driveside crank arm come off. It started because the end cap came off/vanished I bet. It royally rounded off the driveside spline though before falling off too ruining the crankset.
Glad you are ok though. You could easily have fallen into the path of a tired driver.
I'm with northwind on this one, stuff come's loose, especialy on new bikes even when it's tightened up properly in the shop it'll still work lose in the first few rides and need tightening up untill it's bedded down. The manual will have words to those effect.
What make/model crank?
The specific mode of failure might indicate something, crank arms seldom [I]just[/I] come off...
What sort of Crank is it?
How has it failed exactly?
Is anything sheered/stripped/missing from the BB/Crank?
Most importantly Who exactly checked it when the bike was assembled at the shop a month ago? Is there a workshop card/sheet indicating that it was checked?
Am indeed lucky that it wasn't worse. Am definitely thankful for that.
The crank arm is (I think an FSA type one....that doesn't have pinch bolts. Just screws down - and self extracts (quite literally) with a (10mm?) large allen key type tool. The end cap is still on the crank arm! went from feeling crisp...no clunking or play on revolution, no hammy front shifting to SNAP.
One benefit though - the girls in the office are all flocking around. Perhaps I should try this one more often.
The end cap is still on the crank arm!
Good (well not good, but useful), so the retaining bolt is still present?
What it the state of it and the BB axle it was previously fitted to?
You're looking for:
a Sheared bolt?
Stripped thread(s)?
Or a snapped off stub of axle still in the crank arm?
Photos might be handy...
you will get at least £1500 assuming you can no longer wash your won clothes or go out
Wonders if true or an allegory
If true heal fast OP and you will win something as they probably wont fight
Photos might be handy...
I'll try later - except my phone is now out of action.....
The end cap is still on the crank arm!
This is interesting. Take LOTS of pics- high res from many angles. Also Docs/correspondence etc.
That shouldn't have happened. Its not blame culture. You bought a product that failed- causing injury and loss.
Re the crank bolt/end cap, on some cranks it's retained in the arm (Raceface frinstance) so that'd be completely normal if the bolt came loose, think some folks might be jumping to a wrong conclusion.
I agree that "check before every ride"'s unreasonable but that's just an example, point is that most bikes will come with sort of advice re ongoing maintenance. How many miles has your month included? Hora's spot on that servicing by months rather than miles is pretty hopeless, for lots of folks a "6 week service" means 1 or 2 rides and an annual service is all their bike ever needs.
You said you regularily check bikes etc, had you ever done this one? If you've checked the cranks (correctly) then that'd rule out incorrect assembly but not faulty parts. And it'd obviously change the picture re general loosening.
(this isn't trying to pick holes... Well, ok, it kind of is but if you're going to pursue it with the shop you're going to want to clear up any pickable holes now!)
How many miles has your month included?
230, Northwind
I did a wee sly edit btw!
I think after 230 miles you'd have to accept that the bike was bolted together properly when it left the shop. IME cranks tend to fall off within miles (if not less) of the bolt coming loose so if it was the bolt coming loose then it'd be down to you as part of some sort of daily/weekly/monthly check to see if they were tight.
Stripped threads won't tell you anything, if a bolt comes loose then the crank falls off it would pull out any remaining threads. I think you can only blame this on the manufacturer if there's something actualy broken.
I agree that "check before every ride"'s unreasonable but that's just an example, point is that most bikes will come with sort of advice re ongoing maintenance.
Be interesting to see if that affects liability, though - last time I bought a motorbike no one expected me to check if the bolts were all tight after a couple of rides just in case.
I bet it was an FSA one. In my experience some of them do this - they work their way lose and if you don't realise the feeling of them being a bit lose they fall off. I have experience of a few, some were alright and others just kept working their way lose not matter how often it was torqued it up.
I would certainly go back to the shop and explain your case to them. Hopefully you will get a nice new Shimano crankset which doesn't work it's way lose. Good luck with the rest of the stuff... 🙁
4week old cyclocross bike with an FSA omega crank..
The DRIVE side worked loose from the axle (it's with FSA at present for inspection - awaiting their outcome). No external influence,heard a metallic clonk when pedalling hard uphill & then noticed side to side movement of 5mm each way - could have sheared off!
mogrim - MemberBe interesting to see if that affects liability, though - last time I bought a motorbike no one expected me to check if the bolts were all tight after a couple of rides just in case.
Redundancy/overbuilding innit, you can build a 200kg motorbike to a different agenda than a 10kg road bike. It wouldn't be hard to build a pushbike that'd be less maintenance-touchy but no bugger'd buy it because it'd be expensive and heavy and hard to maintain.
But you can spec more or less reliable bits.
Mmm that sounds nasty hope you're OK. My instinct would be to go back and insert the fallen off crank arm in the manager, however that wouldn't be productive. I'd go back, explain the situation and politely ask them how they plan to rectify the situation to the original state.
I found loose stem steerer clamp bolts (among others) on a brand new hybrid on day 2 of riding. Not overly happy would be an understatement of my mood, went back to the shop and came out with a £50 voucher so some places do care, a bit. They obviously felt a wee bit guilty I had a check sheet that one of their scrotes, I mean mechanics, had signed saying every bolt was thoroughly checked to manufacturers' spec.
Sounds like your crank bolt wasn't tightened properly or maybe the arm did actually fail catastrophically in some way. Either way this sort of thing should not happen with a brand new bike even if it has gone 230 miles.
What other mechanical item needs so much fettling after purchase? As said above I'd be pissed if I bought a new motorbike and it was my responsibility to check all the bolts after the first 50 miles. Likewise with a car or even a lawn mower. There shouldn't really be much onus on you for ensuring a bolt on a brand new bike is tight.
Good luck.
[url= http://singletrackworld.com/forum/topic/self-loosening-crankarm-on-comet-fsa-m18 ]Spooky[/url]
Oh, just a thought- crank fitting isn't usually a shop job if it's a full bike, they'd be fitted at the factory. Shop should pdi it and check for tightness etc.
Spooky
indeed - I'd forgotten about that! But that was working loose gradually though on my friend's Boardman HT. But a thorough clean, regrease and retighten has resolved it, That one has been good for a year or so now. No further issues.
Mine is on my road bike. No warning. No pre loosening. and a couple of hundred dry road miles under the belt.
The common denominator is that they are both FSA.....
Redundancy/overbuilding innit, you can build a 200kg motorbike to a different agenda than a 10kg road bike. It wouldn't be hard to build a pushbike that'd be less maintenance-touchy but no bugger'd buy it because it'd be expensive and heavy and hard to maintain.
Yeah, but I'm not sure that argument would hold much weight if you took it to court - I very much doubt market share is a reasonable excuse for a dangerous product!
I bet I'm not the only one who'll be double-checking their cranks later 🙂
Sounds like your crank bolt wasn't tightened properly or maybe the arm did actually fail catastrophically in some way. Either way this sort of thing should not happen with a brand new bike even if it has gone 230 miles.
It's not really brand new after 200 miles though is it, I'd expect if it hadn't been torqued properly in the shop it would have fallen off on the way home. If it's come loose at the 200 mile mark then that's the owners responsibility to have checked that once in a while, the shop couldn't gaurentee that the bolt will stay tight indefinately, hence the owners manulay will have had statements that the bolts should be checked periodicaly.
What other mechanical item needs so much fettling after purchase? As said above I'd be pissed if I bought a new motorbike and it was my responsibility to check all the bolts after the first 50 miles. Likewise with a car or even a lawn mower. There shouldn't really be much onus on you for ensuring a bolt on a brand new bike is tight
No one said 50 miles, 200 miles is 20 hours, so that's arround the time you'd (or rather the garrage) be giving a motorbike it's running in service, which would probably include checking the more important bolts were still done up properly. As said, the onus isn't on you to check the bolts on a brand new bike (although for the sake of your dental bills it's probablya good thing to do), that's the shops responsibility. After a month/200miles though it's not new, and I think any reasnoble person is probably going to check them as part of their routine maintenance, ESPECIALY on a nearly new bike where you know things are going to loosen off as they bed in.
Yeah, but I'm not sure that argument would hold much weight if you took it to court - I very much doubt market share is a reasonable excuse for a dangerous product!
Not anything to do with market share, I bet there's more FSA chainsets to that design than there are of any given motorbike's crank. The point was a cyclists expects the bike to be light and well built to make it between fairly frequent service intervals, a motorcylists expects the same parts to last 5,000-10,000miles.
mogrim - MemberYeah, but I'm not sure that argument would hold much weight if you took it to court - I very much doubt market share is a reasonable excuse for a dangerous product!
Except who says it's dangerous? Requiring more maintenance doesn't make something dangerous. (though it might be- we still don't know if it came loose, or failed outright)
At lunchtime I re-checked all my 2month-old roadbike HTII bolts 🙂
Update - I'll try and get a photo on later as have taken some with the SLR.
You can clearly see that the non-drive side crank arm thread has stripped. There's a "curl" of metal floating around and where the thread should be has a large bald spot. Hard to explain without the photo, granted...but to me looks like it has probably been cross threaded on installation.
Pleased to say that other than really stiff neck muscles and sprained ankle, everything else seems to be in order today!