Mountain bike: 64 km/h verified, possible 80km/h another time (much steeper hill)
Motorbike (my partners old 125 Honda BROS): 115 km/h?
My R32 GTS Skyline: 160 km/h (was passing a truck - have no inclination to see what the actual top speed is, thus haven't tried)
My R32 GTS-4 Skyline: 180 km/h (hit the speed limiter relatively quickly, and with three people in the car - only did it once just to see if it did have a limiter).
Fastest i've been though was a ride in a mates 600hp R33 GT-R. He got it up to 280 km/h (also passed a car like it was standing still/reversing

) before the straight started slowly turning into corners/humps. I drove it back home afterwards and didn't really want to speed in it, but got it up to maybe 130 km/h or more while being squashed back in my seat passing a slow car. Never looked at the speedo as car was squashing me back in the seat so much that i just had my eyes glued to the road.

I know it was in third gear anyway.
God that was fun.

Don't think the car i passed was too pleased, as after i pulled back in they turned on their high beams (in broad daylight).
Unfortunately he rolled the car in a hill climb a few weeks later and wrote it off.
