Home Traveling Adventures Hawaii: Cycling the Old Mamalahoa Hwy to Akaka Falls

Hawaii: Cycling the Old Mamalahoa Hwy to Akaka Falls

by bromptoning

NOTE: We travelled Hawaii in February 2020, before the WHO declared COVID-19 a pandemic and the world went on lockdown. So rest assured we’re blogging post-travels and currently at home. Stay safe, everyone. — Heather & Pier

This was an epic ride with breathtakingly beautiful scenery and a rainstorm of biblical proportions. We avoided the new Mamalahoa Highway 19 (aka the Hawaii Belt Road) for all but two one-kilometre stretches. We couldn’t avoid the rain, though we did dodge it once, but it came back with a vengeance on our ascent up to Akaka Falls. 

I thought we were prepared for a downpour. I was so wrong. We have never in our lives experienced rain like this! At the end of this post, I’ll share what we learned and how we’d prepare for this rainy ride if we ever get lucky enough to do it again.

Distance – 30km

Average Speed – 14km/hr

Top Speed – 40km/hr

Cycling Time – 2 hrs 8 mins

Total Trip Time – 4 hrs 26 mins

Elevation (Highest/Lowest) – 370m / 0m

Steepest Grade – 14%

Climbed – 690m

*Komoot recorded the steepest grade as 26%, but that’s where we walked our bikes on the narrow path to Onomea Bay. So that doesn’t count. The next steepest section is 14% cycling out of the Honomu Stream gulch. Our ascent to Akaka Falls averaged a 7% grade, but near the top it hit the steepest section at 11%!

Route Planning – Avoiding The Belt Road

My goal was to keep us off the main highway as much as possible, not just for better scenery and exhaust-free air, but for safety. Though there are paved shoulders on most of the highway, they’re pretty narrow and I’d heard of sections where the shoulders disappear, usually in the worst places like heading into a hairpin turn down in a gulch. In fact, I saw some of those shoulder-less gulches on our bus ride from Kona to Hilo. With that in mind, I created a route on Komoot combining side streets, side roads and the Old Mamalahoa Highway Scenic Drive. I’d find out later that the ENTIRE route I’d created consisted of the Old Mamalahoa Highway, it’s just that the sections of it close to Hilo have been given street names.

First Leg 🚴 – Hilo to Papaikou

We headed out of Hilo by crossing the Wailuku River on Wainaku Street (which was once the Old Mamalahoa Highway), and in less than five minutes it started to rain. No problem. We had our rain capes. And in a few minutes, the rain stopped. This is how the weather had been in Hilo during our trip — rain, sunshine, rain, sunshine, repeat. Though it was calling for much more rain the day we did this ride, we were confident we could handle it. Oh, we were so innocent!

Past the tiny town of Wainaku, we had to cycle on The Belt Road for about 1km past the cemetery before turning right onto Nahala Street to Honoli’i Beach. This black sand beach is a prime surfing and boogie boarding spot, and we saw plenty of locals getting ready to ride the waves.

Honoli’i Beach, The Big Island, Hawaii
Honoli’i Beach

We continued on the same street, though as it crosses under the Mamalahoa Highway Honoli’i Stream Bridge, its name changes to Kahoa Street (yes, this too is the Old Mamalahoa Highway), and headed into our first gulch of the day.

Old Mamalahoa Hwy bridge over Honoli’i Stream, The Big Island, Hawaii
Old Mamalahoa Hwy bridge over Honoli’i Stream

As you can see in the photo, the asphalt is rather neglected on this old highway, but there were enough smooth patches that cycling on it wasn’t a pain. And once we got into the next little town (Pauka’a), it was freshly paved!

After another very short section on the new highway’s narrow shoulders…

Brompton bicycle on The Belt Road shoulder. The Big Island, Hawaii
Brompton on The Hawaii Belt Road shoulder

…we picked up the old highway and cycled on it through the town of Papaikou until it curved back to cross the new highway again. This intersection is where there’s a big sign that simply reads: SCENIC DRIVE. So we crossed and began one of the most famous stretches of the Old Mamalahoa Highway on The Big Island.

Second Leg 🚴 – Scenic Drive: Old Mamalahoa Highway

Scenic Drive over the Kaieie Stream

The Scenic Drive is a 4 mile section of the old highway that winds through dense jungle foliage and traverses centuries old narrow bridges along what was once a footpath between villages. About a mile in, just before the Hawaii Tropical Botanical Garden, we took the Onomea Bay Trail down to the shore.

Old Mamalahoa Highway Scenic Drive, The Big Island, Hawaii
Old Mamalahoa Highway Scenic Drive, Hawaii
Old Mamalahoa Highway Scenic Drive, The Big Island, Hawaii
Old Mamalahoa Highway Scenic Drive, Hawaii
Bromptons arrive at Onomea Bay. The Big Island, Hawaii
Bromptons arrive at Onomea Bay.

The trail is easy to miss; we noticed it because a few cars were parked beside the road at the entrance. So we stopped to investigate. This trail down to the shore started out ridable, but quickly became sections of steep stairs. Luckily, our Bromptons are light and easy to carry. At the bottom is a beautiful inlet looking out at Onomea Bay.

Onomea Bay, The Big Island, Hawaii
Onomea Bay
Onomea Bay, The Big Island, Hawaii
Heather & Pier at Onomea Bay

Continuing on the Onomea Bay Trail brings you to the back entrance of the Hawaii Tropical Botanical Garden. We decided not to go to the official gardens, and instead parked our bikes on a sign and walked the Donkey Trail to the next inlet.

Then we returned to our bikes and went back up to the Scenic Drive. We stopped to take a picture on the historic wooden bridge over Kawainui Stream…

Brompton on historic wooden bridge over Kawainui Stream, The Big Island, Hawaii.
Brompton on historic wooden bridge over Kawainui Stream.

Then we continued to What’s Shakin’ for lunch – arriving just as it began to pour rain again!

What's Shakin', The Big Island, Hawaii
What’s Shakin’ – let’s eat!

After refueling and waiting out the worst of the rain, we continued on to Akaka Falls!

Third Leg 🚴 – Pepeekeo to Akaka Falls

The final mile of the Scenic Drive connects to the Hawaii Belt Road just north of Pepeekeo. We pass a farmer checking on his cows, and he tells us we’re going to get rained on! We say we know and we’re prepared. He probably laughed at us in his head, because we were not at all prepared for the torrential downpour that was about to hit the east coast of The Big Island. 

We’re only on the new highway very briefly before we get back on the old highway, which is now mountainside of the new highway. This is where the downbursts of rain start coming closer together, and we leave the rain capes on.

Windy, rainy ride along Old Mamalahoa Hwy to Honomu, The Big Island, Hawaii
Windy, rainy ride along Old Mamalahoa Hwy to Honomu.

Just before the town of Honomu and turning onto Akaka Falls Road, we ride down into the last gulch of the day, over Honomu Stream.

Heather on the Honomu Stream Bridge. The Big Island, Hawaii
Heather on the Honomu Stream Bridge.

And right as we turned left onto Akaka Falls Road for a 5.2 km (3.2 miles) / 275m (906 ft) ascent, it started to DOWNPOUR! The heaviest rain we’ve ever been in. And it NEVER LET UP. 

Cycling up ‘Akaka Falls Road in a torrential downpour!
Pouring buckets at Akaka Falls, The Big Island, Hawaii.
Hiding under shelter at Akaka Falls.

This is the first time we have ever gotten wet under our Cleverhoods. We were literally soaked to our underwear. But we made it to the top and went to see the falls, though they were hard to see with all the pouring rain.

Because we were soaked through and had stopped cycling hard uphill, I suddenly got very, very cold. Being wet is one thing, but shivering uncontrollably while trying to ride downhill in the STILL pouring rain? I did not want to do that. And once we got downhill, would there be a cafe open on a Sunday in Honomu where we could warm up? And would the pounding rain ever stop? 

Both seemed unlikely—hardly anything is open on the non-touristy side of the island on Sundays (What’s Shakin’ being the exception to the rule), and that rain was relentless.

So we asked the only other tourists who were at Akaka Falls during the downpour if they were, perchance, driving back to Hilo. Luckily, they were and agreed to give us a ride! Our saviours!

Lessons for Cycling in a Hawaiian Downpour

Hilo is the rainiest city in the USA. It gets on average 142 inches (or 3,607mm) of rain a year, and rains 236 days of the year. So yes, we knew it was going to rain. We had rain covers for our bags, and rain capes for ourselves. That had been sufficient on all our other travels. We’d worn the Cleverhoods in tropical downpours in Mexico and some pretty intense thunderstorms in our own home city of Toronto. Even our first few days in Hilo consisted of short downpours with breaks of sunshine. We were confident we were prepared for rain, even though the forecast on the day we rode to Akaka Falls was calling for something crazy, like 90mm of rain! What even was 90mm of rain?

We sure found out. We’d never seen it rain SO HARD for SO LONG. We’re used to downpours that last for 10 minutes or so and ease up to a lighter rain or drizzle. However, according to Komoot, it took us exactly 30 minutes to bike up the Akaka Falls Road, and during that time the sky never stopped dumping buckets on us. And it continued pouring while we were at Akaka Falls and during the drive back to Hilo. 

By the time we arrived in Hilo, it was a light rain, but that might just be because we’d traveled out of the worse of the storm, not because it actually stopped raining in Akaka Falls. We’ll never know.

What we do know is that if we’re ever cycling somewhere that’s calling for an insane amount of rain, we will pack a spare set of clothes in a dry pack. Oh, and have a back up plan if the rain doesn’t let up. I now know that a Hele-On bus stops in Honomu, the little town at the bottom of Akaka Falls Road. Though that wouldn’t actually have helped us since the buses don’t run on Sundays! Nope, we definitely needed a spare set of dry clothes and extra raincapes. Thank goodness we had the kindness of two strangers and folding bikes that fit in their compact car’s trunk! Yay, Bromptons!

Overall, this was a beautiful ride with very little traffic on the narrow old highway roads. Highly recommend! Just be more prepared for rain than we were. 

And that was our last adventure in the Hilo area. The next day we caught the bus back to Kona.

Hawaii Bike Rides so far…

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eldo August 24, 2020 - 11:55 am

There are times when fenders come in handy……..fabulous trip, thanks for posting,

bromptoning August 24, 2020 - 12:06 pm

Glad you liked the post! Thanks for reading! Our Bromptons most definitely have fenders (wouldn’t travel without ’em!), but when the rain is bouncing up off the pavement AND blowing sideways, fenders don’t help much. 🙂


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