cbr125r is not an economically viable option for streamlining. The cost of a super efficient streamlined fairing is too costly compared to the amount of money saved on fuel (I have been quoted $5,000 for thermoformed fairing and $1,200 for polystyrene model from which to make a mold of). There is no saving to be made even on 100,000km. The saving of 40% on fuel represents only AUD $1,409 over 100,000km.
I am now exploring super efficient electrathon style vehicle for road travel (even petrol power is too wasteful so I must go electric). These vehicles often use three 20" bmx wheels. The closest to this I can find is for motorcycle are shinko 16" 2.25" tires.
Amazon.com: Shinko SR714 Series Moped Tire - Front/Rear - 2.25-16 , Position: Front/Rear, Tire Ply: 4, Speed Rating: L, Tire Type: Scooter/Moped, Tire Size: 2.25-16, Rim Size: 16 XF87-4550: Automotive
But I cannot find the wheels to go with this tyre. I also don't know what spoked motorcycle wheels weigh so cannot make any concrete decision on the most energy and cost efficient tyres.
This is quite the predicament.