3w ago

What is this piece and how do I fix it?

Got an old bike that has this piece in between the crankset and the frame. It’s very loose and keeps rolling around and getting in the way of the chain when I pedal. How can I remove it or make it stay fixed in one place?

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Is it a mount for a chain guard?
If you can't take off the cranks and remove it, maybe tin snips and cut it off?
- Definitely the piece for the chain guard.
- It could be. I can’t think of anything else it might be either. I’ve never taken of cranks, I guess I need some special tools? It seems to be reasonably thick so I’m not sure if I can cut it off.
  
  Those will be square taper cranks. They can be a pain to remove, but sometimes are okay. Remove circular plastic cap and there'll be a nut down inside the crank. One side will be left hand thread, the other right hand. You'll need a socket that is very thin walled. Undoing these can be hard, but getting the cranks off the square taper is usually the more annoying part as the cranks get jammed on. I've often had to bash them off with a hammer 😅
  (If you're actually going to attempt this, probs worth watching a youtube tutorial)
  
  Yeah, from what I understand, not easy to remove cranks without special tools. Dremel might work, but maybe a bike shop might be easier/safer/quicker.
  Edit: short term fix, zip tie it to the tube so it doesn't move?

That's a hand, and don't worry, it's just got a glove on it.
- That makes a lot of sense but is it safe to remove? I guess there’s an extra one on the other side…
  
  You have to be very careful if you want to preserve the use of the glove.

here’s another photo from a different angle

can confirm, this is for a chain guard. if you are going to remove a crankset/arms, it is best to use a proper crankset removal tool. the last thing you want is to fuck up your crank arm or bottom bracket and have a malfunction during a critical moment aka any moment you are on a bicycle. i had a friend’s crank arm strip as he was riding into a 4-way intersection. scary times.
anyway, never hurts to invest in proper tools for your bicycle. if that’s not viable, take it to a local bike shop & ask for help. they might do it for cheap or even for free, since it is causing a safety issue, or you can just get a new chain guard.

Confirm that this is a chainguard holder. I am not sure if it's supposed to turn around like that, because with the chainguard present it wouldn't, so maybe it's by (shitty) design.
Anyway, it is safe to remove if you don't want to install a guard now

It's a plate to mount your chain guard to, the only way to remove or replace those is if you remove the entire crank bearing because it is mounted though that to keep it in place.
First you'll need to remove the cranks, pop the plastic cover, and use a 14 mm socket to remove the bolt, you can either use a dead-blow carefully or use a bicycle crank puller if you have one (this is easier).
You'll need a specialized tool to remove the cups, however looking at the retaining ring on the other side it looks like this one is metal. If you have a blunt chisel and a hammer you can try and use that. But be careful, you do not want to damage the threads in the bike, if you do that there is no way to fix them and you can throw it away.
After removing the entire bearing hub is out, the chain guard mounting place can be removed and you can reassemble the bike again if you are not replacing it with a new one.
I don't know for sure anymore but it can be that the fasteners are all tightening towards the front, meaning one will tighten clockwise and the other side counter clockwise.
This is based on my previous experience working in a bicycle repair shop.

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