Twisty doesn't work

The simplicity is easy and yet, I have problems with some as they age. For instance on the the Peak Eigers and those before them. At some point, the foam spacer deteriorates and about that time, the light ceases to work. Peak has sent new bodies and I've bought spares. I don't understand why this happens. I don't need blazing output, just enough to put sufficient light out for up close tasks in dim places. These Peaks lights are fine. The Peak head works on other Eiger bodies so the head is fine. I tire of the body replacement.

I've attempted to clean the lower contact, rough the surface up for a better contact...fail. What is causing this? Is there a simple fix for me to attempt?

Replace the squashed foam...and, it's fixed.

I haven't seen a foam style body in several years. You might consider upgrading to one of the 2.1 bodies. They can be built in QTC and non QTC configs.

You may need to clean the threads on the non-working bodies, and remove and clean the negative contact (if a keychain body). The threading can hold dirt and debris, preventing sufficient contact.

Looking at it, I suspect that when the battery is inserted, it might be squishing the foam down between the body. The twisty motion just continues to tear the foam more preventing contact. These are the only twisty bodies that give me problems.