That

[jack]

http://www.stoptech.com/whitepapers/...erformance.htm

1. It is the combination of these two functions – braking force at the tire versus weight on that tire – that determine our braking bias. (What's the subject and what's the verb for 'determine' ? Why isn't it 'determines' ?)
Thanks.

[Casiopea]

The subject is underlined:

A. two functions determine (verb). . . .
B. The combination determines (verb). . . .

[jack]

1. It is the combination of these two functions – braking force at the tire versus weight on that tire – that determine our braking bias.

How come the subject for the one above is 'two functions'? Not 'it' ?)

1. One of these cars is good. (The subject here is 'one'? )

[Tdol]

It should be 'determines'.

[HCaulfield]

The subject is "One of these cars" which is singular.

The subject in the first sentence is "the combination of these two functions – braking force at the tire versus weight on that tire". The it used is just "structural", isn't it?

The whole sentence can be rearranged to give:
The combination of these two functions – braking force at the tire versus weight on that tire - determines...