Bicycle Mechanics - Please help mounting a bell on headset, 2012 Trek 7.2FX

I want to mount a bell on the headset of my 2012 Trek 7.2 FX. Velo Orange carries the type that I wish to buy, however, I am unsure of exactly which mount would be used in this particular application. I think that I would need to get the BELL ON A HEADSET SPACER. Is that the right one for this bike? Thanks in advance.

The 'bell on a headset spacer' is the correct one, in 1-1/8" size. You'll have to remove one of your spacers and replace it with the bell.

Specifically, this is the model with SKU: BE-1004 for $19. The issue you may have if clearance above and below if you've modified your headset stack at all with larger cups/wider needle bearings. But I've seen a shop owner modify the mount for the bell to add length to the threaded rod to extend the bell a few mm further out, and I've also seen the same collar spacer with mounting hole modified but with a different bell model (a Sanrio Hello Kitty bell). I don't have the specific threading though for the hole in the spacer. But you can buy just the spacer with that mounting hole for trying that mod yourself with your own bell design for $5 + S/H.

Now maybe Shimano STI could come up with brifter-bell combos.... shift, brake, and ring that bell simultaneously! LOL!

Thanks so much.