You can beat the bike race without using boost slide, but it's darn near frame perfect (about .1s leeway), and you need to hit every recycling boost, including the one that you don't get a chance to do until after touching the jump pad.
By the way, when I beat the biker, he didn't give me his bike. I just got a "Speedo", that $1 purchaseable in deep town (which I had skipped buying) that tells you your current speed. Out of curiosity, I went back to Deep Town and purchased the original Speedo. Two speedometers sitting in my inventory now, still no bike. </3
PS: While vertical movement is kind of a pain until you get wall jump, movement in general in this game is INCREDIBLY fun once you have all the vertical mobility upgrades. You did good, seven. <3