RSS
It's often a good idea for combat opponents to have some form of weakness that the PCs can exploit if they're clever. It gives them a way to feel clever, and provides some variety instead of every combat being just whittling away at hit points.
An important corollary of this is that it should be possible for the players to work out what the weakness is, either logically, or by observation potentially helped along with some hints. If members of an opposing humanoid tribe recoil from fire or light, that could indicate a way to weaken or harm them.
Commentary by memnarch (who has not seen the movie)
.... Huh. I guess they are actually on treads of some kind. But why? That'd be such a mess to maintain in a sandy environment. Jet troopers wouldn't need a boost like that to get into the air either. Maybe it's just to be able to tell which vehicles are which in far away scenes? That'd almost make sense, except for the bit where the main characters are being chased and would always be in front.
Nice that we get to see the split between the characters here. It looks like we've got Rey and Chewie on one speeder, and Poe, Finn, and Threepio on the other one. BB is too short to be visible, but looks like they're on the speeder with Rey and Chewie for character balance. I don't think there's much that the droid duo can do, but maybe BB will have some sort of trick inside. Grapple hooks on the jet troopers maybe?
Transcript
Chewbacca: I fire my plasma crossbow at the pursuers.
[SFX]: Pow! 15!
GM: Not enough with all the motion penalties.
GM: <roll> You lose your footing.
GM: The treadspeeders launch jet troopers into the air!
[SFX]: fwooosh! {two troopers with jetpacks fly up and ahead of the treadspeeders}
[SFX]: grunkgrunk...
[SFX]: fwooosh!
[SFX]: grunkgrunk...
C-3PO: They have the high... air!
[SFX]: wooosh! wooosh! {the jet troopers close in on them}
Chewbacca: Huh. Their tactics might actually be improving.
Rey: On the other hand, they have containers of combustible fuel strapped to them.
Finn: Go around opposite sides of that outcrop ahead!
Poe: Split up?
Finn: Split them up.
Rey: I veer right!
[SFX]: vrrrumm...
Poe: I veer left!
[SFX]: wubwubwub...
GM: The jet troopers follow Rey, Chewie, and BB-8.
[SFX]: wooosh! wooosh!
[SFX]: Pow! Boom! {the jet troopers fire at the speeder and an explosion rocks the sand behind them}
[SFX]: vrrrumm...
Rey: Chewie! One hit will take them out!
Chewbacca: So, I just need to be Chumbawamba with aim.
GM: You get knocked down, and you screw up again...