What will be keep this "loose" HI-LOW RD screw in place?

[Veloo]

Working on this bike that has a Tourney 7 speed RD and the black plastic piece where the HI-LOW screws are broke.
Really don't think it will stay in place if I try to glue it back cuz the connection points are uber thin.
Looks like this plastic piece helps to keep the screws in their place.

The one screw is able to turn more freely than I would like as this is a kid's bike. And of course the plastic spoke protector broke.

Will some thread locker keep it in place? Found some red and blue. Hopefully they're still fluid.

If not, what else would keep the screw from working loose and allowing the RD from hitting the spokes?

[bigbill]

Perhaps a narrow strip of plumber's tape wrapped around the threads?

[5oakterrace]

I thought plumbers tape too. Another alternative is to take the screw to a hardware store. The aubuchons I frequent has a board where you screw in the screw into different size holes to figure out what you need if you do not know size. You might try that to get a slighter bigger/tighter screw to fit. You probably mess up the threads but it looks like the part will need to be replaced anyway in time. Just another alternative.

[slambers3]

Thats like a $10 commonly available derailleur, I personally wouldn’t spend a ton of time running through all available repair scenarios.

[Peter P.]

Beeswax. Rivendell used to tout this stuff as a very mild threadlocker. I don't know if it will work with such fine threads.

Do NOT use Red threadlocker. It will require heat to break the bond otherwise, you can forget about turning the screw.

Use Blue Loctite 242, which is a medium threadlocker whose bond is easily broken. I also see Loctite sells a low strength threadlocker, particularly suited to small, fine screws.

Lastly, you could try any spoke prep formulation. Spoke threads are roughly the same diameter and pitch.

[elvisthehorse]

Don't use normal thread lock. You want to use one that is reusable.


Vibra-TITE VC-3

Vibra-Tite VC-3 Threadmate
Prevent fastener loosening from shock & vibration
Vibra-Tite VC-3 Threadmate is one of the most versatile threadlockers available on the market. Unlike conventional liquid lockers which cure to form a hard bond, VC-3 is a blend of resins designed to remain flexible and absorb vibration. This unique difference makes VC-3 coated fasteners truly adjustable, removable, and reusable. Great for fasteners ranging from tiny set and eyeglass screws to huge construction bolts.

Adjustable, Removable & Reusable
Compatible With Fasteners of Any Size
Works on Metal, Wood, Plastic (PPE, PP) & More
Excellent Coated Shelf-Life


its kinda like dt reusable spoke prep but way cheaper. I have my rear derailleur screws on my KK trainer and would vibrate out of adjustment. This reusable thread lock fixed the issue.

[xlbs]

Springs from an old pen...

[bart998]

The spring was an interesting idea... I was thinking remove the rest of that plastic piece and thread a small nut onto both screws and lock it down against the base once the derailleur is adjusted.

[2metalhips]

A slight nick in the the threads with a file or wire cutter might work.