How do I tighten this chain cover (with pics)

[united4ever]

This cover thingy (not sure what it's called) is wobbly and I guess rubbing on the chain a bit. I thought it would be a simple tightening job. One side is an alan key which is already really tight...I took it out again and retightened but it seems that doesn't affect the position of the plastic chain cover. The other side is fixed with something like a screw but doesn't have a screw head or alan key access - it's like a domed piece of rigid plastic that I cannot easily get off - do i need to get pliers on that? Or am I missing something obvious here? Hopefully the pics attached illustrate better.

 

[Spiderweb]

I presume you’ve tried nipping up the rusty Alan key fixing which faces to the front of the bike. I would have thought that was the clamp for the guard thingy.

 

[figbat]

I presume you’ve tried nipping up the rusty Alan key fixing which faces to the front of the bike. I would have thought that was the clamp for the guard thingy.

This.

There are three areas of fixation. The clamp around the seat tube, the grub screw holding the arm clamp (the rusty part mentioned above) and the bolt that holds the chain guide to the arm (which you appear to have investigated). I have one of these on my gravel bike and it can be a faff to get it all lined up and clear of the chain with three axes of articulation, but once tightened up I have never had to revisit it.

 

[united4ever]

Thank you! that was it - I don't know how I missed that...not much clearance on the chain but at least now it is tight and appears not to be making contact. Thanks again

 

[Cycleops]

Never seen one of those before but I guess It's to ensure the chain doesn't do a whopsee on the 1x setup.
Thanks for letting us see it.

 

[figbat]

I must admit I don't run mine quite that close to the chain and I have a narrow-wide chainring so I have no idea if it is even doing anything - it was added as insurance during the bike build after reading that without a clutched RD I'd be dropping the chain all the time.