Fans!

[Bionic-Badger]

That's 38mm deep. He needs it 25mm or so.

 

[Things]

Yeah, reason it needs to be so thin is because it has to fit between the motor and back wheel. 25mm works but I've only got maybe 1-1.5cm clearance to the back wheel, and probably ~1cm to the motor, so even 25mm is kind of pushing it

 

[Rainbow]

I got bored and was looking at fans and found a few you might be interested in.

Delta EFB0812LB 80x15mm Low Speed

Delta EFB0812SH 80x25mm Triple Blade High Speed

Sunon 80mm x 25mm Extreme High Speed Fan - 50.6 CFM (KD1208PTBX-6(2)318.AF.GN) - FrozenCPU.com

Delta 80mm x 15mm Fan - Bare Lead (AFB0812LB-F00) - FrozenCPU.com