Viewing 40 posts - 1 through 40 (of 48 total)
  • XT Crank Fail
  • Premier Icon slowjo
    Free Member

    Half way through lap 1 of the Thetford Summer Enduro yesterday,I had an unexpected mechanical. I was prepared for most eventualities but not this…


    P1020593 by gouldjpg, on Flickr


    P1020592 by gouldjpg, on Flickr


    P1020590 by gouldjpg, on Flickr

    I finished the lap pedalling with one leg, handed over to my partner and then rushed home to get another bike.

    The cranks are a few years old now but I didn’t anticipate such a catastrophic failure.

    (The chainring bolts are missing as I was in the middle of stripping it down.)

    Premier Icon Tom83
    Free Member

    1st time I’ve seen that!

    Premier Icon trail_rat
    Free Member

    not the first time ive seen that

    seen it before on oOOOLD xt cranks that had seen a power of miles – foot rub basically wore the front thin – but you could see it clearly – the photos above dont actually look so bad) and cracking initiated in the front judging by the colours of the material i was looking at – the rear of the crank was shiny and fresh broken the front was dull and grey looked like it had been going for a while.

    Premier Icon schmiken
    Full Member

    Were you on the Singular?

    Premier Icon BearBack
    Free Member

    Doh

    Premier Icon billyboulders
    Free Member

    Eeek – my xt cranks are the same vintage as those and worn pretty shiny on the fronts too, time for new ones maybe. Glad your ok though could have been nasty if you were flat out halfway down a rocky descent!

    Premier Icon slowjo
    Free Member

    schmiken – yes, that was me!

    Trying to put a positive spin on it….. I managed to do left footed pedal drills for 4 miles! 🙂

    Premier Icon Cheezpleez
    Full Member

    Blimey! I’ve got two sets of those in regular use 😐

    Premier Icon Liftman
    Free Member

    I had an SLX crank snap like that except it was the chainring side that snapped.

    Premier Icon JoeG
    Free Member

    Its just a sticker!

    Premier Icon slowjo
    Free Member

    eh?

    Premier Icon spacehopper
    Full Member

    i’ve had a set of those crack in about the same place too.. put that down to heel rub..

    and another set i managed to bend and then rip the pedal clean out of threads on a drop..

    I don’t buy XT cranks anymore! 🙂

    Premier Icon I_Ache
    Free Member

    I didn’t realise how hollow they were. I just thought there was a little pocket in the middle. Bit nervous about getting rid of my Saints for SLX now. 😐

    Premier Icon fasthaggis
    Full Member

    That wouldn’t have happened with flats 😉

    Premier Icon mattjg
    Full Member

    That’s a bit worrying ….

    Premier Icon stimpy
    Free Member

    Its just a sticker!

    😆

    Premier Icon mattjg
    Full Member

    Might be worth sending those pics to Shimano to advise them and see what they say. Cranks are safety critical kit, they need to know if they’re failing.

    Premier Icon bigyinn
    Free Member

    If you look closely at the pics the out face of the arm looks to be alh the thickness of the inner. Thats a lot of heel rub!
    I doubt that you can afford to lose that much material without component failure!

    Premier Icon pictonroad
    Full Member

    extraordinary spelling of half bigyinn…

    Premier Icon z1ppy
    Free Member

    Bigyinn ain’t wrong:

    eddkh

    original thread

    Premier Icon samuri
    Free Member

    I’ve had some deore cranks break exactly like that, a long way from home.

    Premier Icon nickjb
    Free Member

    It would be interesting to cut them into a section like zippy’s image to see if it is local wear. If you don’t have tools I’d be happy to give it a go. Left hand one might be in a similar state.

    Premier Icon Northwind
    Full Member

    Enjoying the concern here, stuff breaks, if in 2013 you’re hearing about failures of what is I think a 2009 model (?) then it’s doing alright. Seen a couple of SLX do the same but then I think some people try to get SLX to do more than its paygrade.

    Premier Icon edd
    Full Member

    I cut one of those, an XT M760, in half once (obviously mine is a non-drive side). This is what it looked like:

    Shimano XT Hollowtech II Crank by eddkh, on Flickr

    Premier Icon bigyinn
    Free Member

    Apologies for the spelling of “half”, I normally pick that sort of things up. Too much beer sat night!
    z1ppy’s pic confirms what I thought.
    Not a warranty issue thats for sure!

    Premier Icon wwaswas
    Full Member

    that is a lot of missing metal compared with the 2nd pics.

    do your shows have a nice metallic sheen to them?

    Premier Icon mattjg
    Full Member

    yeah Edd’s pic shows equivalent thickness on the inner and outer sides of the arms, Jo’s pic shows a lot less on the outside!

    (as a compulsive heel-rubber, I’m off to look in the shed …)

    Premier Icon slowjo
    Free Member

    Agreed, a lot of metal has worn away. The thing is, it isn’t something you expect….even after years of pedalling!

    Ideally, some form of wear indicator would be a good idea but I have no idea how you would do it.

    I’m not sure Shimano would be interested, as mentioned previously, they are hardly new. I’d just have preferred it if they had gone nearer the end of the lap! 🙂

    Premier Icon wwaswas
    Full Member

    maybe some helicopter tape on the new ones!

    Premier Icon RustySpanner
    Full Member

    Interesting.

    Ms S is a serial heel rubber and has some, ooohh, 7 year old XT on her Rock Lobster.

    Ooops.
    Is there anyway to judge effective lifespan?
    How worn is too worn?

    Northwind – Member

    Enjoying the concern here, stuff breaks, if in 2013 you’re hearing about failures of what is I think a 2009 model (?) then it’s doing alright.

    You think 4 years is an acceptable life span?
    Wow. I would expect them to last pretty much indefinitely unless severely damaged or heel rubbed to hell.

    Seen a couple of SLX do the same but then I think some people try to get SLX to do more than its paygrade.

    Jumping/downhilling you mean?
    If XC use, I’d expect them to last just as long as any other model of Hollowtech crank.
    Lifespan isn’t model specific, is it?

    Not trying to be funny, just interested.

    Premier Icon 3dvgirl
    Free Member

    Shimano will still replace recalled cranks from the mid 1990’s id contact them.

    Premier Icon mattjg
    Full Member

    It’s more about amount of use rather than lifespan. I accept I’m a heel rubber, I don’t think there’s anything Shimano can do about that short of making 5kg solid cranks.

    A wear indicator would be handy but I suspect ain’t gonna happen, so I guess the rule is if in doubt then get rid. The potential costs and consequences of a failure far outweigh the cost of replacement.

    Premier Icon Northwind
    Full Member

    Rusty Spanner – Member

    Jumping/downhilling you mean?

    Yup. Tons of SLXs on dh bikes- I got on fine with mine but then I weigh as much as a child.

    Bear in mind here we’re not talking about a “4 year lifespan”, we’re just talking about a couple of items failing after 4 years, on a popular line. What’s the mean time to failure going to look like? Not 4 years, that’s for sure.

    Premier Icon wwaswas
    Full Member

    Maybe use some calipers to measure a new pair and then get rid after a certain (how much???) has worn off?

    Premier Icon bigyinn
    Free Member

    3dvgirl – Member

    Shimano will still replace recalled cranks from the mid 1990’s id contact them.
    Im happy to be corrected on this point, but im not aware of any recalls on Hollowtech cranks.
    Besides there is a clear cause of why the cranks have failed. Is not a manufacturing defect, but a direct result of excessive heel rubbing.

    Premier Icon ahwiles
    Free Member

    mattjg – Member
    …I don’t think there’s anything Shimano can do about that short of making 5kg solid cranks.

    deore cranks are solid (although the back of the arms are scalloped), and weigh a whopping 100g or so more than xt.

    Premier Icon londonerinoz
    Free Member

    Measure from new and check occasionally seems very sensible.

    Thankfully I’m not a heel rubber, but if I was I’d add cranks to the list of items that get replaced periodically to avoid a crash or injury in the event of age/use related failure, such as handlebars and helmets.

    Premier Icon 3dvgirl
    Free Member

    Im happy to be corrected on this point, but im not aware of any recalls on Hollowtech cranks

    no they were altus ones i think. I have just read the instructions for my crank it makes no reference to watch out for heal rub etc. like i said id contact them, if only for the sake of feedback, you might be surprised how interested they are.

    Premier Icon samuri
    Free Member

    Found my old deore ones.


    snapped-deore2 by Jon Wyatt, on Flickr

    Now *that’s* worn out. 😉

    Premier Icon mattjg
    Full Member

    ^^ !!

Viewing 40 posts - 1 through 40 (of 48 total)

The topic ‘XT Crank Fail’ is closed to new replies.