Bike route from wahiawa to waikiki/Downtown?

I admire you for want to ride bike, I assume you mean bicycle, not motorcycle, yeah? So, best way from Wahiawa to Waikiki/downtown gonna be take State Hwy 99 south, stay on till get to 92, which take you to Waikiki/downtown, ok? This very feasible, BUT, coupla place with interchange that you have to get onna OLD 99, not NEW 99, mobetta that you look at high relief map, you see what I mean, ok? Same for 92, but course once you get to Nimitz, no problem, yeah? Now, can't say it "safe", but for sure you can do, ok? Lotta people do onna Moped alla time, so you can do too, ok? Peace and aloha to you!

It's a long and not necessarily safe ride. But if you'd want to try, Google Maps does have a bike route search.

That's a pretty dangerous route. I wouldn't feel comfortable with anyone biking that route. But if you insist, I think it's a good idea to follow what the other guy said.

Not too many Hawaii residents would know. Perhaps you could call one of the bike shops or the triathlon shops in Honolulu. Another option is to take the Bus a little bit and then bike.