Name that part ...
 

I should know what this caps off, but ... I'm coming up empty.

https://cimg6.ibsrv.net/gimg/bikefor...f69535bcd7.jpg

https://cimg5.ibsrv.net/gimg/bikefor...fdee45093e.jpg

I'd say a quill stem

I think it may be too small for that. I should've provided some size reference... Let me edit and re-add a pic with a reference up above.

It's barely bigger than a QR spring.

Could be a cap for internal cable routing port.

They REALLY look like quill stem caps for those cheap adjustable-angle aluminum quill stems common back in the early 2000s. Those stems had a sloping surface where the bolt was recessed into. Even the size seems right. I remember back when I worked at a bike shop, prying those out with screwdrivers to do adjustments on new bikes. They almost never got put back in.

scarlson nailed it!

I'm no good with pics. Can you hum a few bars?

I think I have one of those stems on my relatively new acquired Jamis Exile MTB:

https://live.staticflickr.com/65535/...c625c673_c.jpgUntitled

It takes a fairly long 5.5mm hex wrench to get at that stem bolt; weird design.

Yeah I've have a few like that. Right now the Deda on the Serotta has a larger one of these as do the Icon Stems on my one Lemond and Y-Foil. One of the bikes I moved on this year had a little one like that, I just don't remember which.

I don't doubt everyone replying here is correct, just having a hard time picturing it. I think the part in question using this bit probably came 6-8 years after my last working stint in a shop and that may be why I'm having a hard time placing it.

When I first saw it, I thought of the annoying caps Huret has on their Eco and Duopar rear mechs. The rounded shape and rubberiness with the smaller size was throwing me off - not even as big around as a Corn Nut, and why would you want pliable rubber covering a derailleur fixing bolt or pivot?

Anyway, I think you guys nailed it. Thanks everyone for chiming in. :D

Here is my bomb around town bike with a riser stem. It has a stem cover like show above.
https://cimg7.ibsrv.net/gimg/bikefor...6d9469bb93.jpg
https://cimg9.ibsrv.net/gimg/bikefor...03e974511e.jpg

Cover caps for triathlon or time trial brake levers similar to these?

https://cimg3.ibsrv.net/gimg/bikefor...d83edc55e5.jpg

Cheers