A cranking bad day

caradale Posts: 34
edited February 2015 in Workshop
What a day, nice calm morning so set of in good spirits for a blast round the vale of Belvoir.
After about 5 miles I started feeling a funny occilation in my left foot while pedaling so pulled up to check what was wrong. first obvious thing was cleat bolts, nope all fine there. pedals next yep left pedal had half unscrewed itself, no problem I carry a multitool so tightened it back up and of we go. It only lasted a couple of miles before the wobble came back, right really crunch it up this time and carry on.
One mile further and the wobbles back, before I could find a safe place to pull over the pedal came off the crank completely and was dangling from my shoe.
Tried to put it back in again but the threads weren't mating at all.
Seven miles one footed pedalling home was horrifically slow painfull and unpleasant.
Back home and took the crank of the bike and cleaned it up a bit and yep virtualy no thread left.
Why this happened has baflled me as they have been on the bike for eighteen months without a problem, why suddenly start chewing up the threads now.
Anyway up to the local LBS who told me that as my version of 105 is about seven years old (fc5600) they couldn`t source a matching crank and said the only options were either a rummage on Ebay and hope I get lucky or a new complete crankset, bugger.

Would a new chainset 5750 be compatible with my existing 5600 stuff.

This was my first ever mechanical in years of cycling that ive been unable to fix or bodge at the roadside so well ticked off with it all.


  • Ebay if you're skint but I'd use as a golden opportunity to buy some new, totally guilt-free, cranks :-).
  • keezx
    keezx Posts: 1,322
    Befre you screw in your left pedal in anything else, check for binding bearings.
    No pedal should unscrew by itself without being something wrong with it.
  • keef66
    keef66 Posts: 13,123
    Unless you're feeling particularly wealthy I'd get on Ebay or look at the classifieds on here. You might be lucky and find just a LH crank arm, but any Shimano HT2 crankset will be compatible with your BB / other kit. If you want a quick fix I have a 4500 Tiagra 52/39 chainset doing nothing...

    (actually bought the entire groupset off a fellow forumite but after a year I've had to admit my elderly knees have no use for a 52 chainring and I've fitted a 46/36 CX chainset )
  • Matthewfalle
    Matthewfalle Posts: 17,380
    Just get a helicoil slapped in there - cost youa tenner and be as good as new.
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • jgsi
    jgsi Posts: 5,062
    Just a quick question... any chance that your pedal axle had seized?
  • Hi all thanks for the reply`s and suggestions , pedal seems to be spinning freely so that seems fine thanks
    keef66 thanks for the offer mate but my knees aren't man enough either for a 52/39.
    Matthewfalle thanks ive had a look at the helicoil thing (didn`t even know such a product existed) and that's defo worth a bit of thought.
  • johngti
    johngti Posts: 2,508
    Have a look in the classifieds, there's a few crank sets in there at the moment. Depends if you'd be happy with something used.