Snapped inner ring!? How and what do I do now? (pic)

PT_Craig
PT_Craig Posts: 28
edited March 2014 in Workshop
Was slowly approaching a bridge today, standing on the pedals to see over the hump in the middle, when I pushed down on the pedal I heard a clanging noise and couldn't pedal any more. Looking back I saw a piece of my inner ring sitting on the road!? On further inspection my inner ring looked a right mess, I tried putting the chain onto the big ring but for some reason it kept slipping off straight away.

I dont really have any mechanical knowledge when it comes to cycling so I have no idea why this would happen and also no idea what to do now. I've been looking at buying a new Tiagra chainset from Wiggle (£50) then taking it to my LBS to fit however someone suggested buying this instead...http://www.spacycles.co.uk/products.php ... 0s210p3055

My bike is a Bianchi Tiagra 2012 model, i've probably ridden about 2500 miles on it so far and have never had any problems with the chainset or gearing.

IMG_1336_zps32ea46ea.jpg.html

Comments

  • DKay
    DKay Posts: 1,652
    Inner chain rings are very easy to come by and that's all you will need to replace on the face of it. There are many different people who manufacture them, including Shimano. All you need to remove and fit one is a large screw driver and a set of allen keys. It's a five min job.
    N
    N+1
  • balthazar
    balthazar Posts: 1,565
    It's an uncommon failure, but not unknown. The forces transmitted by these components are very high. It's undoubtedly a fatigue fracture, partially cracked through for hundreds of miles before it finally fell apart. (I'd be interested to see a picture of the fractured edge). As DKay says, chain rings are easily replaced cheaply- they're "wear" items anyway.

    If the chain wouldn't run on the big ring afterwards, it possibly got bent somewhere when the ring failed. Check it thoroughly or, preferably, replace it anyway. Chains are cheap too.
  • me-109
    me-109 Posts: 1,915
    Check the arms on the crank spider to see if they are all still straight enough. I had an FSA crank fail on me (I think one of the chainring bolts went first, bending the inner ring and then one of the arms on the spider) that was nearly new and, as ever, impossible to claim as a warranty.

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