I had no idea one could purchase a Grasshopper a la carte. Have you bought a separate back end from them?
Yes, but you will need to email them and ask for it to be added to the cart, assuming they still have some available. If they're out of titanium ask for a stainless one
Cost is iirc 75 for Ti. I've purchased an extra TI clicky, my friend has purchased a stainless one. He was annoyed that it took a while to ship, i was happy it was added to the cart the same day I asked
I gave him a 2016 stainless back end to pair with the new titanium spare body that I purchased for him in September. He decided he needs a spare back end bc he keeps dropping the f****** thing so often.
doesn't really seem to matter as far as back-end (clicky unit) vintage compared to what body component is in play:
I purchased a complete full TI unit at the same time as the TI spare body that I used to build a complete unit from older spare parts. I tested them both and there was no difference in performance except that the one with the stainless back end got ever so slightly warmer on the back end after many cycles
By the way I don't know what the fuk happened but all of the colored spare bodies that I bought in august had problems so stick with the not-colored titanium would be my recommendation (blue char on 1, purple char on 1, green DoA). This was from August tho, so maybe everything from September forward is safe.