Allen bolts on Amazon

[Mike Dupre]

I moved my RAD UI display and forgot to tighten one of the screws and lost the screw. I can't find anything in the manuals or specs. Does anybody know the size of that bolt... M2  2.5 ? looks about a cm in length but there's that cap head, what am I looking for on Amazon? 

[JimInPT]

Can you specify which model bike and which display, if one of the newer 2-screen models?  I switched to the aftermarket 35A display/controller last year, so can't specifically answer your question, unfortunately.

Whenever I have an issue like yours, I just take one of the remaining screws to my local hardware store and match it to something on their shelves.  Always test-screw on a nut as well to confirm you have the right thread pitch in addition to size.  Depending on the stock screws, this might be a good opportunity to change them all out to a high-quality stainless-steel version if appropriate.

And don't forget to buy one or two extras for the next time!

[Mike Dupre]

HA! forgot to mention the bike. Yup, I shudda biked over to HomeHardware but I don't like leaving my city 5 plus unattended (locked or not) So I ordered the wrong size from Amazon twice and ended up finding a couple suitable bolts in my treasure chest. I was kicking around that stainless steel idea but I don't even let that bike get wet.
Thanks for the tips!

[handlebar]

I like to smear Flex Shot on threads. Even if I forget to tighten a fastener, the rubbery friction will keep it from unscrewing. Any RTV would do, but an opened can of Flex Shot has a longer shelf life, in my experience.

A set of drill bits can be used to find the minor diameter of the required screw and the maximum thread length.