I do not like adding weight or packing extra stuff but here are a few light things that are really useful and take up very little space and weight.
You can never have enough duct tape. I typically wrap tape around my tool handles as it keeps the tools from rattling and gives you tape in a way that doesn’t take up space. I have also added pre-cut “Nuke Tape” from Best Rest Products (maker of the cycle pump – which is fantastic) https://bestrestproducts.com/product-category/nuke-tape/
I don’t really care that it really is Duct Tape rated for use by the “Nuclear Regulatory Commission” I like it because its in pre cut strips and is flat – its very useful tape in a even more convenient format.
I discovered Gear Aid mini patches when I was at Overland Expo. I really like them as they are useful for patching specific items that duct tape is not great for. Coats, Sleeping bags, Tents, and they even have specific types of tape such as GORE-TEX, Reflective, Mesh, Etc.. These little patches are great for camping and don’t take up space or weight and are worth a consideration. https://www.gearaid.com/products/tenacious-tape-patch-mini
If everything else fails a compass and a whistle will go a long way. I have Brunton TruArc 3 – Base Plate Compass $15-$20 in most of my vehicles and or packs. Its a classic base plate compass and is equipped with the TruArc™ Global Needle. But how do you use a Compass? What if you want to head a direction other than north? If you only learn one thing about a compass it should be how to Put “Fred in the shed” or “Red in the Shed” Watch the video to learn more.
When you walk away from your bike into the woods this will help you make it back to your bike, or in the case that the GPS and cell phone break you can have a heading with something that works day and night without batteries.
The $6 safety whistle is just that, a simple cheap safety whistle. There are two things to consider. First: If you want someones attention for help most people respond to a whistle. Secondly: more importantly is if you can breath then you can use a whistle where as screaming for help will only last for a few hours and then you loose you voice.