Did I Don Goofed - Pedal Falling From Crank Arm

SAM28
SAM28 Posts: 6
edited October 2014 in Workshop
Hi Guys,

Took my Felt F95 on first 5 mile road ride to the gym today.

However on the return journey on left padal became loose, hand tightening it back in place and then slightly with allen key on my multi tool.

As soon as I put my weight on the pedal however it came loose/fell to an angle.

I've have strapped pedals, so I kept my right foot in the strap and my left sat on top of the left pedal so the strap was facing the ground (in hindsight not a good idea)

Can't work what I've done though guys.

I've fairly overweight (around 20 stone), but surely the weight I'm placing on the right pedal is the same but that seems fine, unless by not putting my left foot in the strap I've put more force on the pedal.

I can only think I've damaged/destroyed the treads on the crank arm as the pedal now slides straight in and out with no resistance/doesn't screw in.

I've attached some photos below showing the damage.

Any mechanics know what damage I've done? Can it be solved with a new bolt or is the crank gone after its maiden road ride.

Cheers,
S

2014-10-19181654_zpse75b61fb.jpg

2014-10-19181635_zpscc4cae89.jpg

2014-10-19181531_zpsd929cb5d.jpg

Comments

  • The threads in the crank arm are stripped, a decent LBS might be able to fit a helicoil, but more realistically you need a new crank set. You say the bike is new, makes me think whoever fitted the pedal either cross threaded it or over tightened it, if this was an LBS then they should pay for the new crankset.
  • Take it back to where you bought it from and get it fixed under warranty - from what you detail above you've done nothing to cause this, its an assembly and/or manufacturing fault.
  • SAM28
    SAM28 Posts: 6
    xdoc wrote:
    The threads in the crank arm are stripped, a decent LBS might be able to fit a helicoil, but more realistically you need a new crank set. You say the bike is new, makes me think whoever fitted the pedal either cross threaded it or over tightened it, if this was an LBS then they should pay for the new crankset.
    Take it back to where you bought it from and get it fixed under warranty - from what you detail above you've done nothing to cause this, its an assembly and/or manufacturing fault.

    Thanks for the reply guys, might not be an option for me as I bought the pedals with the bike, but attached them myself, followed a few youtube videos, used grease etc. but from the feedback it look's like I've tightened it to much?

    But surely as I damaged it in installed it should have slip out straight away or while it was on the turbo trainer?
  • lesfirth
    lesfirth Posts: 1,382
    It will not necessarily fail immediately . It looks like it has been crossthreaded or not tightened enough. I doubt you could over tighten it. An assembly problem. However you need a good bike shop to fit a helicoil insert. It will be, apart from a bit of cosmetic damage, as good as new then. Cost ,except in London of course, about £10/15.
  • DeVlaeminck
    DeVlaeminck Posts: 8,907
    Try refitting the pedal, see if you can get it in and tighten it up. If you can't then see what a bike shop can do, worst case is crank has had it but see what you can do with it first. I once put a pedal into the wrong crank, removed it and fitted the correct pedal and it still worked ok.
    [Castle Donington Ladies FC - going up in '22]
  • Ahh didn't realise you fitted it, helicoil or new crank then
  • trailflow
    trailflow Posts: 1,311
    Sam, are you aware that the pedal threads in the crank arms are opposite to each other ? i.e. you screw in the pedal towards the handlebars on each side of the bike to tighten them. As this is on the non drive side ,have you accidently screwed it in the wrong way ?
  • lesfirth
    lesfirth Posts: 1,382
    trailflow wrote:
    Sam, are you aware that the pedal threads in the crank arms are opposite to each other ? i.e. you screw in the pedal towards the handlebars on each side of the bike to tighten them. As this is on the non drive side ,have you accidently screwed it in the wrong way ?

    If he has screwed this one in the wrong way he has also screwed the other side in the wrong way! Any threaded bit on your bike ( or anywhere else) should screw in several turns with your fingers. If you can not, sort out why. Never force it in with a spanner or wrench.
  • frisbee
    frisbee Posts: 691
    lesfirth wrote:
    trailflow wrote:
    Sam, are you aware that the pedal threads in the crank arms are opposite to each other ? i.e. you screw in the pedal towards the handlebars on each side of the bike to tighten them. As this is on the non drive side ,have you accidently screwed it in the wrong way ?

    If he has screwed this one in the wrong way he has also screwed the other side in the wrong way! Any threaded bit on your bike ( or anywhere else) should screw in several turns with your fingers. If you can not, sort out why. Never force it in with a spanner or wrench.

    I guess you could screw them both on the same way i.e. both clockwise. But it would take a huge amount of force, even into an aluminium crank, and the thread wouldn't pull the pedal onto the crank.
  • keezx
    keezx Posts: 1,322
    Some shops sell separate left cranks (for square taper axle), is a better option than messing around with a knackered crank.
  • keef66
    keef66 Posts: 13,123
    That looks like the Wiggle special F95 with Sora and the FSA Tempo crankset. Thought it looked familiar; son's just bought one.

    I found him trying to remove one of the pedals from his old bike by turning it the wrong way :shock: That took some undoing!
  • Monty Dog
    Monty Dog Posts: 20,614
    Helicoil will be stronger than the original thread, no need to junk the crank. Guess it's only a mistake you'll make only the once?
    Make mine an Italian, with Campagnolo on the side..