Giant Defy 3 (2010) broken crankarm

[kasioris5]

Hello, all lovely people. I have some serious issue that's been going for a while now. My Giant Defy 3 (2010) left crankarm is indeed broken. It was good until I removed the whole crankset from the bike and I had to use a great amount of force to untighten left crankarm since it uses hex key in the middle. Now, every time I screw the crankarm back in, it untightens after a few kilometers. I believe that my crankarm's thread has been damaged and it lacks a serious amount of metal, that's why it untightens after a short distance. Can someone help me out to find an exact same crankset to buy, and in a perfect case, maybe just the left crankarm? Call me a retard, but I can't seem to find the exact model of my crankset on the internet. I believe it's FSA Omega Mega Exo as it tells on the manufacturer's page https://www.giant-bicycles.com/gb/defy-3-2010
Anyway, I'll include some photos and video so you guys can get a better hint of what I'm talking about

 

[Arjimlad]

You do know to loosen the two smaller bolts holding the crank arm onto the axle before undoing the cap on the outer face of the arm ?

I'd imagine you need a complete new crankset because I'd guess that the axle is damaged.

 

[Deleted member 35268]

You only mention the central hex bolt and not the other two side bolts. The side bolts do alot of the retaining. I have a 2009 Defy and there are a multitude of replacements you can get. I will try and point you to some for sale. Your best bet is a complete crankset.

 

[Deleted member 35268]

I don't know your crank arm length or chainring teeth setup but this will be the sort of thing for your 9 speed triple

SHIMANO SORA FC-3503 TRIPLE CRANKSET, 50/39/30 - 175MM

Or just try and get a replacement FSA Omega Mega Exo crankset like this one on Ebay

 

[r04DiE]

retard

Can you do me a favour and stop using that word?