2019 Mt. Diablo Challenge

We represented with 4 unicyclists at this year’s race. Weather was great, with little to no wind (~3mph SSW). Starting at around 43F and ending at 63F for my ride.

Mt Diablo Challenge is an uphill cycling race. There’s been many unicyclists at the event in the past (long before I even started riding :slight_smile: ).

Ben: 1:06:59.8
Harrison: 1:09:06.6
Josh: 1:29:01.1
Jim: 1:45:36.3

Ben’s new record time is incredible! People I talked with afterwards said he was riding faster than some “professional bicyclists”. :sunglasses:

As far as riding sub 1-hr, I think a 36" or a guni 29"/36" is almost necessary. (and crazy fitness. I’m not even close to 1hr on a bike)

Since I rode a 29"x2.35" ungeared, I decided to look at my data a bit.
Sub-1hr would require spinning at around 125rpm for the whole time. That’s how fast I was spinning when the gradient was around 0-1%. Most of the ride is 3-10%. The picture below shows my average speed/cadence for different grades throughout the ride. (total avg speed for me was about 15.3

Interesting thing from the chart (maybe real or just data inaccuracies), is that my cadence deviates higher than gps speed for higher grades around 8-10%. My hypothesis is that I ride in a more squiggly path when it’s steeper.

Ben’s facebook post with photos :slight_smile: :

(it’s supposed to be 11.2mi = 18.0km, but I think my garmin underestimates and says 17.6km)

I’m really interested in Uni-climbing and thats some detailed analysis there!
And some very fast riding!!!

It would be nice to know the wheel size and cranks used by the unicyclists that competed.

I just searched Strava for the stats of this event and get different results for length, elevation and average grade.
Do you happen to know the correct one?

Mt Diablo Challenge Blackhawk, California 17.5 963 5%
Mt. Diablo: Mount Diablo… Diablo, California 17.9 990 6%
2013 mt diablo challenge climb Diablo, CA 17.4 960 6%
Mount Diablo Challenge Diablo, California 17.9 962 5%

Earlier this year I participated in “Climbing for life” with stats:
Ballon D’ Alsace: 8.9 km, 707m, 4.9% in 1h40min (my own strava data, including relatively flat warm up 1st km)
Planche de Belles Filles : 7.9 km, 552m, 7.0% in 1h6min (my own strava data).

My times are “moving time” because I took some breaks.
I would have to check separate segments to get better climbing info.

Now looking back at your “real” times I’m even more impressed!!!

At 1:15 minute: Ben Soja rippin’ it up

Question: did Ben complete the Everest?
On the blog where I originally found the YT video the writer suggests so.

Yes, this is Ben`s post on facebook.

I rode. 29"x2.35" with 125mm cranks.
Ben: 29"x2", 137mm, geared
Josh: 26", not sure about crank, geared
Jim: 29"x2", not sure about crank

Around 17.6km to 18.0km, at about 5.5% average grade, so those are all approximately correct… Maybe someone else knows how to get a more accurate length/elevation.

I found out about everesting here on the forum but never found out if an unicyclist ever succeeded.

Now I know :grinning:
Simply amazing!

Great effort guys! I love reading up about these challenges. Good to have the detailed analysis too.

Kudos for spinning that fast on 125’s. Did you consider going shorter?

Maybe I’ll come and do one of these hillclimbs next year!

Harrison, great effort and analysis!

Let me contribute a comparison of our efforts. This shows where the Schlumpf is faster and where it’s worse. My time (pink curve) is relative to Harrison’s (black straight line). The elevation profile is in the background. In the first half, I gained 3 minutes and in the second half, where it is steeper, I lost 1 minute. The green boxes are the sections I rode in first gear, and that is where I lost most time. It makes sense, since when I have to ride in first gear, my setup is clearly worse than Harrison’s (longer cranks and heavier due to the Schlumpf hub).

For this course, I believe my setup (G29/137mm) was pretty much perfect. Unless you go full custom, I believe 36ers are simply too heavy. If the course would a bit steeper, let’s say 7% average grade, ungeared 29ers would probably be the way to go.

Great idea! If you do, you will be welcome to stay at our place, and I’ll show you the historic Muni Weekend trails, or Downieville, and then you can go toward the coast for the famous Santa Cruz area trails, and Rob’s Ride. :slight_smile:

Also congratulations to you uphill athletes; quite an achievement! For less-fit people, our conclusion in 2007, on a training ride for Ride The Lobster, was that the 36" was a little faster, if only because it’s hard to go slower than a certain pace when grinding up most of the second half of the climb. That was Mike Scalisi and me, switching back and forth between 29" and 36". Not very scientific…


I wish I could do a hill race like this. I’m very interested by this thread for some reasons.

Like as saw on facebook, you both have the two lightest 29" wheels in the market, Ben with a schlumpf hub and Harrison without. For a few months, I had been thinking about a setup with a lightbicycle 29" carbon rim and the schwalbe big one tire with the idea of riding road climbs. And the same week, I see your two wheels and the Unigeezer one. I wonder how you chose from the wide choice of rim width and the 2 designs RECON and RECON PRO (Ben ride a RECON PRO). :roll_eyes:
Maybe we (I?) need to create a new thread about the lightbicycle carbon rim :stuck_out_tongue:

About the difference between Harrison and Ben, or rather between 29 and G29, as I can see, the first 10km were about 4%, the last 8km about 7,5%. Even if the first part is not very steep, I doubt the interest of the schlumpf when it comes to climbing.

I also think that a 36" seems to be an interesting wheel size for this climb, but the negative point is that a 36" stealth2 rim + 36" nightrider are more than twice as heavy as a 29" carbon rim + 29" big one tire… I wouldn’t have said that before I climbed Mount Ventoux in July with my G36 (about 10kg, my heaviest unicycle), it wasn’t as hard as I thought it would be.:slight_smile:

I hadn’t seriously thought about shorter. I can see it working better for me now though, now that my fitness has improved. However, I actually think I can still go faster with my same setup.

I would have thought that my low-gradient speed would have stayed about the same as I got faster with the same cranks and wheel size. And my speed for steeper sections would be where I improved the most. However, it seems I was able to raise my speed across the board from my previous attempts, in the first picture.
2017 in green was when it was super windy and I used 150mm cranks. Other 3 years were all 125mm 29er.

In the second picture: my 3 best unicycle times and my best bike time. Even against myself, I made up the most time in the second half. Not sure if that’s good or bad pacing…
First 6 miles, my average HR was 180bpm. Second half I let it go up to 190bpm. I was kind of worried when I first saw 180bpm; I had no idea what HR was sustainable since it’s all flat around where I live now, and I can’t get my HR up nearly as much (165bpm for a 20 minute effort already hurts as much or more).

Interesting my old bike time is considerably slower, and only made up time on the two flat/downhill sections.

May take you up on that, in a year or two!

I raced Unicon 19 on a 29" Light Bicycle carbon rim/Schwalbe Big One setup, which is very light (sub 4kg) but I don’t rate the Big One as a particularly good tyre. It punctures going over not very much, and needs very high pressures to handle camber.

I have a H Plus Son Archetype/Schwalbe Kojak combo which I think would work better for a hillclimb.

Really interesting graphs. I think unicycles are faster than bikes at the right gradient- your power goes directly into the wheel instead of through a drivetrain.

I think some unicyclist are better at at climbing hills because in general they develop stronger legs then bike riders. The power train on bikes have very little loss and turn at an ideal speed most of the time. With longer cranks on a bike, no need to hold back on the up stroke and the ability to coast they simply do not have to work as hard as a unicyclist to cover the same distance. With the added work just to ride a unicycle they develop stronger legs and that is a benefit when the going gets tough on a hill climb.

I think you get fitter from riding a bike, as you can ride a constant and higher resistance with gearing to match the terrain.

Drivetrain loss- may not be much but I’ve read anywhere from 3-6% loss, which would be significant compared to a unicycle, which transfers power directly into the wheel.

Coasting- not an issue for a hillclimb, hence why I said ‘given the right gradient’.

I’m not sure by what you mean ‘holding back on the upstroke’? Most of the power is delivered on the downstroke, and comparing like with like- you can also use clipless pedals on a unicycle.

The idea that unicycles could be faster than bikes, on any kind of terrain, given equivalent rider strength, is completely absurd and contradicted by every data point we have.

But, as you say, there are many unicyclists, including Ben and Harrison, who are faster than many bicyclists. Ben is an amazing athlete who would be beating 1:00 on Diablo if he were training on bike. (Harrison, probably, also). Glenn Drummond, the previous record-holder on Diablo at 1:13 (since 2005), was an extremely strong bike rider, and had finished in the top 5 in the bike category, and still finished sub-1:00 as recently as 2017 (at age 55).

I think you are right.

I am pretty sure the energy loss of the drive train on a good bike is way less than the energy loss of maintaining balance on a unicycle.

And then add to that the possibility to change gears to keep optimum cadence / momentum on incline changes.


I often overtake bicycles when riding up moderately steep and longer hills. It’s not because a unicycle is better up hills, it’s simply that I have no gearing and so have to compensate by riding at the optimum speed for that unicycle’s fixed configuration on that hill. The bicycle rider can change down through the gears as the speed slows, a unicycle can’t. I don’t want to ride some hills that fast, but slowing down is often inefficient and wastes energy so I maintain a speed that works best.

As unicycle riders we must overcome the huge deficiencies a unicycle has compared to a multi-geared and mostly self balancing bicycle, and as such the rider can become a good hill climber, not the unicycle.

A single data point is hardly evidence. In either case, my original statement was regarding a constant gradient, where the unicycle wheel/crank ratio is optimal. If Mt Diablo has lots of different gradients it doesn’t amount to what I said.

Be careful with mechanistic reasoning. The human body is complex and this type of reasoning is the lowest level of evidence that we ascribe a level to.

You could counter that statement with similar mechanistic logic: Most unicyclists spend little effort balancing on the road. Unicycles are lighter than bikes. Track bikes are also fixed gear, it is not an impediment if the terrain is constant.

Yes, I did the same, but there is a paucity of evidence and I was commenting on Harrisons statement, and also on some of my own observations on my own hillclimb routes (as a bicyclist/unicyclist).

This is for Harrison to comment, but it doesn’t look like you should be including it in your ‘data point’:

What I was commenting on, as well as personal data.

I think it can be close between a bike and unicycle.

Bike: At least around 2% drivetrain loss? (exclude tires, assume equal for unicycle and bike).

Here’s an idea to calculate effort required to balance a unicycle:
Going uphill for me, I don’t believe I push backwards more than normal(biking) to balance, it’s just pushing forward more or less.
Thus, my model for balancing is pushing 0-10% more on some pedal strokes, and 0-10% less on other pedal strokes. This makes it approximately up to 1.5% more difficult. (explanation in next paragraph)

For example, instead of riding at 200W smoothly (ie on a bike), you ride at 220W for a few pedal strokes, and 180W for the next few pedal strokes. This is harder than just riding at 200W continuously. Bicyclists sometimes use “normalized power” to describe this. If you average 200W, and never go above 220W or below 180W, normalized power maxes out at around 203W. So it is 1.5% more difficult. This is worst case though… if it’s just 220W for a few seconds, followed by 180W for a few seconds, repeatedly, it’s more like 201W normalized power (0.5% more difficult). Normalized power obviously isn’t perfect, it’s just some equations people thought up of, but it works well enough for bicyclists to gauge their effort.

I think a proficient unicyclist corrects with less than +/-10% variations for a smooth uphill road, so from this point of view, balancing effort could be less than 0.5%.

Obviously, if the correction happens by pushing backwards more, versus just letting up a bit, then it could be be wasting a lot more. With 10% variation, that could be as much as, 10% to pedal harder, then 10% pushing backward, resulting in 20% extra effort. However, I rode Diablo with a powermeter pedals before on both unicycle and bike, and my torque effectiveness was in a similar range as when I bike. So I think my assumption that balancing comes from pedal forward more or less could be true.

As gizmoduck said, with the wrong gradient and thus non-ideal cadence, this easily goes out the window.