I was riding today and somehow my pedal broke off of the crankset arm. Nothing happened to the pedal but I need to replace my crankset. I was thinking of upgrading it to a Shimano 105 fc-5800, 172.5mm, 52/36. The problem is that I don't know if it will be compatible with the chain, cassette and derraileurs that I have. I have an 8 speed 12/25 cassette with Shimano Sora rear and Shimano Claris front derailluers. Eventually I will Upgrade all my Componets to Shimano 105 5800s. For now I just want to see if that crankset will be compatible with what I currently have. Thanks!

UPDATE:

Current crankset is a FSA, 170mm, 50/34. Should i go for the Shimano 105 170mm 50/34. Or can I do Shimano 105 172.5, 52/36. Like I said eventually I will be getting 105 components with the 11 speed, 11/28 cassette and I really wanted the 52/36

Heres some pics of the aftermath. It's the same on both sides. Nothing happened to the pedals. Thank you forum!

what crankset is it? Let us know so we can avoid it!

I would think that combo should work just fine. While maybe not ideal it should work. Depending on the current crank gearing you may need to lengthen or shorten the chain....

The only issue you may have is your 8 speed chain interfering with the 52T ring when using the outer portion of your cassette when in the 36T ring. I experienced this before using a 9 speed crankset with all 8 speed components. However, it was a very small frame with short chainstays which exacerbated the problem. Worst case, you can swap out the chain for a more narrow version to reduce the interference (though this might require a new FD, too, to keep shifting satisfactorily fast).

Was your previous crankset also a double?

It was likely a in-house crankset. I've seen the Fuji cranksets on MTB break twice on the same bike. The LBS ended up replacing them with FSA.

Looks like it had FSA

Product: Fuji Sportif 3.0 LE Road Bike - 2015 Performance Exclusive

Left arms are cheap enough to just buy one , Right arms just buy a New crankset.

This was on a MTB that I saw it break twice. Fuji Tahoe. It had an Oval crankset. Cracked twice on the same spot, left arm where the bolts attach. He also warped on ring on the crankset but that may have been from smacking a tree root.

That's not really a broken crankset, that looks like stripped threads? How did that happen? I think you must need new pedals after that?

It's a FSA crankset. It came with the bike

That looks like someone cross threaded the pedals...

yes, not broken or defective crankset. Lessons learned and excuse to upgrade crankset

I was at a stop and stood up on my bike to start pedaling. When I clipped in and started pedaling it snapped off. Nothing happened to the pedal. The pedals thread looks good as new. The crankset came with the bike so it's pretty cheap I guess.

Looks like a candidate for a helicoil repair. Many bike shops have the tools for this, it's much cheaper than a new crank, and the repair is actually stronger than the original threads.

+1