We were allowed 2.5 hours to make the trip down but it only took us 1.5 hours. The time restriction was more about getting back before their store (bike return) closed. Their hours are very early in the day due to the sunrise tours they offer.

The bike tour does not start from the park but rather outside of it. So you wouldn’t be able to do hiking and bike together. I also wouldn’t recommend the bike trip for families with smaller children because you have to ride on the road in very tight quarters with traffic and at times it can be quite scary even for adults.

That's not something that was communicated to me. I'd suggest calling them directly.

nonya62 is spot on. i'm 52 dad & did the same w/ my 21 yo son. keep eye on weather forecast in that exact area because it's more apt to rain up there than where you're staying. we experienced rain which took some of the fun out of our ride.

If you take the self-guided tour, it's completely at your own pace. Could take you 45 mins or could take you 3-4 hours to get down, depending on stops. It really just depends on what you want to make of the trip. We often stop in Kula for lunch and browsing through the Curtis Wilson Cost gallery. We also stop in Makawao to look through shops. That can add some time. Add 60-90 minutes for the ride up the mountain in the bus. And, if the Makawao Rodeo is happening, maybe add another 90 minutes! Our tour up the mountain was long over July 4th weekend, but well worth it with our driver Bill and his stories/side tours. Keep in mind that the guided tours they do now may last longer (best to call the shop for the expected length). And, any summit tours may take an extended period of time - early morning and higher elevation. Though, in the end, you may still start at the ~7,000 foot elevation. I don't think you can ride through the park anymore.