What's the rarest part you own?

That is proof, if proof is needed, that amphetamines and alcohol don't mix

mmm...a part that came as standard on a mass produced bike in 1988 .....you may have the only remaining 'working' browning ...that is rare.

true

I also have a Rhinotec carbon front wheel bought bitd. The LBS where I got it said they believed it to be a one off prototype...does that make me amazing too? If not, I could make loads of stuff up.

Forgot to mention a couple of NOS Breezer Jetstream frames ..not really old stock as I bought them new bitd, and probably quite scarce in this condition.
NOS Proshift rear mech in bling-tastic red and polished-alum'.
Prototype Topline crank which no large-ring will quite fit!
Ahead Ti flexstem combo, adapted by me so not sure if it counts (or if anyone cares!)

There's a NOS working one in my spares box. The only reason it's still working is that it's never been used on a bike. Browning + bike + water and dirt = a swift return to normal gears

Does an unfinished prototype frame count? (note to self : sell the darn thing because you'll never build it anyway)

If not, I still have a NOS Altus A10 groupset as well.

Pair of NOS Kooka racha brake levers, Altek shark fin levers, 2000 Tomac buckshot with no scratches or blemishes and 1995 Giant TCM

how is all this rare

I have these bars too!