Help!: Gear tracker and using multiple of the same item e.g. tyres

Hi,

I want to be able to track use of the same type of tyre on my bike separately as the rear wears out before the front. When  I add 2 of the same item I can only choose one tyre at a time from the drop down when I am adding gear to track against a ride.

I tried to add a new gear type of "bike tyre front" and "bike tyre rear" but then I put in the manufacturer the site tells me it already exists but will not show it as choice. 

 Either I am stupid or this is a serious limitation for tracking gear for cyclists.

 Any ideas or suggestions on how I should do this?

Thanks

Peter