What Size Bullet Connector ? (noobee question)

[SSgt Duramax]

No, there is no one size for motors & ESC’s. However, 3.5 mm is the most common size.
I’ve seen bullet connectors in several sizes 2, 3, 3.5 & 4 mm. In my shop, I have made everything 3.5 mm. For the smaller motors 2 mm. If I happen to get a motor or ESC that has a different size connecter, I’ll change it, solder on a new one. Likewise, all of my battery connectors are XT60 or XT30. If I happen to get something that is different, I'll change it. Life is much better when everything is the same size.

Bullet connectors and battery connecters are cheap on eBay, pick the size you want, learn to solder and change them out.

I'm the same. I think it is best to have a variety. On my smaller motors (I just go with whatever the size of wires going to the motor are) I usually like to use the 2mm ones. Some motors come with them soldered on already. My 1806 motors all use 2mm connectors. It looks better, they are lighter, and you don't have a tiny little wire going into a huge oversized connector held there with a glob of solder. It also helps with the shrink wrapping when your wire size is close in size to the connector. Ever try to shrink heat shrink from a really large connector to a really small wire? It doesn't work well as the wrap only shrinks so much.