Coach Cronk’s Leadville 100 MTB ‘Big Buckle’ Race Report

A trip to Colorado was always on the cards in 2025. One of my best mates lives there and a visit was overdue. With the iconic Leadville 100 on his doorstep, it made sense to enter the lottery. Unless you qualify at US races, it’s the only way in. Places were announced in January and I got lucky. I’d secured a place in one of the world’s toughest and most famous MTB races: 105 miles, 3,500m of ascent over five major climbs, an average altitude of 3,000m. For context, no Tour de France climb goes as high as the starting altitude of this race! Finish inside 12 hours and you earn the small finisher’s buckle; under nine hours will get you the legendary handmade “Big Buckle.” A lure that attracts racers from around the globe.

Training and Build-Up

Now, I could write a thesis on this section, detailing every; type of interval session, race simulation, kit choice, fuelling quantity and race day strategy, but 90% of you would fall asleep. If you’re one of the 10%, a geek like me and interested in the minutia then leave a comment or drop me a message with any questions.  

April nearly derailed my preparation. A minor surgery spiralled into pneumonia, leaving just twelve weeks to get back on track and prepare. With Laura’s backing (“it’s just twelve weeks, do what you need to do”), I stripped my training back to four sessions a week to maximise rest and minimise the chance of being sick again but kept the overall volume as high as I could manage, building to 14 hour training weeks. Fridays were reserved for long rides that built steadily to 7–8 hours. Fuelling became the breakthrough: 80g carbs and 750ml fluid per hour being the magic number for me. By the last few big rides, I couldn’t believe how strong I still felt six hours in.

The rest of the week was about quality: VO₂ max intervals, lactate clearance work, long tempo climbs. Using the road or MTB depending on the type of session.  By July I was hitting the targets I’d need on race day, climbing consistently at 800+ VAM off-road during long rides. Slowly, belief grew.

Altitude was the great unknown, it would affect my performance but by how much? The best practices are to either acclimate fully or arrive late. With only ten days in the US, I chose late: Boulder Wednesday (1,600m), Frisco Thursday (3,000m), and race Saturday. Also leaving time to hang out with the Evans family after the race.

Race Day

Alarm at 0400. By 0600, I was in my start corral, the furthest one back with well over 1000 people in front of me, the price you pay for entering via the lottery and not via a qualifying event. Teeth chattering from a combination of the cold, nerves and caffeine I squeeze my bike in at the front of my corral, leave it there and head for the portaloo. A long toilet queue was actually a blessing, a chance to be on my own for a bit. I hate hanging about on the startline.

At the gun, the rollout was calm, but chaos arrived quickly on St. Kevins; riders walking, bottlenecks, nowhere to pass. I’d heard about the difficulties of starting this race at the back, but folks walking just twenty minutes into the race? This sucks! Things space out a bit and I’m on my bike for the second half of the climb, albeit slowly in long lines of riders. Target times across key parts of the course were tapped to my top tube and I crested the first climb five minutes behind target. I told myself, ‘you’ve got eight hours to claw that back, don’t change your game plan.’

Climb two, Sugarloaf Pass, then the sketchy Powerline descent; steep, rocky and no place for gravel bikes, yep I said it! It’s a MTB race folks (those who know the race will know the right bike for the job is debated hotly, at no point during that race was I unhappy with my bike choice!). A rider clipped my shoulder at speed taking a gap that wasn’t there, the sketchiest moment of my whole day, if we’d clipped bars we both would have gone down. Onto the rolling sections and I tucked into small groups, encouraging everyone to work together, saving energy where I could. Some of the elite riders who are already on their return leg start passing, I recognise; Keegan Swenson, Dylan Johnson, Sofia Gomez & Hannah Otto. Racing on the same course, at the same time as some of the world’s best is an experience you just don’t get in other sports, pretty cool!

Then the Twin Lakes feed zone exploded into view; flags, bells, music, thousands of people. Evo was recognizable thanks to the Sonic the Hedgehog balloon (we forgot the Welsh flag), bottles, bars and gels ready. “Mate! I’m two minutes ahead!”

Columbine

Columbine is the halfway monster with about 900 metres gain, topping out at 3800 metres. I settled into my rhythm, riding well and waiting for the upper slopes known as the Goat Track to come into view. We broke out of the tree line and an intimidating line of riders walking snakes towards the summit. I rode as far as I could before it got too loose and rocky. I’ve heard the altitude really hits most at this point but I find myself jogging sections to overtake as many people as possible. The summit came and I took a moment to down some coke before the long descent. I felt I’d ridden this section well but the numbers stung: somehow I was a full ten minutes behind theoretical sub-nine pace!

We’re over half way and retracing our steps,  the head wind was brutal. For a while I let go of sub-nine and just had to be content with doing my best. I concluded that if I was slipping behind pace with a tail wind on the way out the deficit would only grow from here. But at the ‘Outward Bound’ feed zone, mile 80, against the odds, I was back on pace! Evo and the family were waiting with fresh supplies and Shae had made a sign for me! ‘Go Cronk, Go Fast!’ Morale was fully restored, as for energy, well I’m not going to lie, I was on my limit at this point. I knew I had a monumental effort to go if I was to pull this off.

Powerline and Carter Summit

So they say ‘the race starts at Powerline.’ I jokingly say it to a guy next to me as we turn towards this cruel beast. I walked the steepest lower slopes, as most do, then set to work, weaving across the jeep track looking for the best line and overtaking carefully. The climb dragged on but is way more scenic than the ugly photos under the power cables suggest. At the top, I was wrecked. My vision blurred, maybe caffeine (600mg by now), maybe dust, maybe just fatigue.

I treated Carter Summit, like it was my finish line. Hoping I could recover enough on the descent for the more mellow few miles back into town. I was swaying, drooling, fighting to keep the cadence up. Emotions started building; Laura having put up with months of focussed training, the Evans family shouting on the course, Ann & Pete flying out to Slovenia to help while I was away. This was bigger than me. ‘Don’t you dare get back on that plane with regrets Cronk.’

The Final Push

Blurry eyed I backed off a smidge for the final descent, I wasn’t risking a puncture now. My brain was cooked, I’d struggle to tie a shoelace let alone fix a tire. The tracks levelled out but the headwind was strong, a guy steamed past and gestured for me to jump on his wheel but I just couldn’t close the gap.  Then came a cruel shock, The Boulevard, not the finishing straight I’d hoped for, but another rocky climb when I thought the asphalt was imminent. I locked onto my average speed, 11.8 mph, needing to hold above 11.7 for a sub-nine, ‘Don’t let it drop.’

Finally, the high school football field appeared and only asphalt remained. With 300m left, I launched one last ugly sprint, I felt a full body cramp incoming but held it together, just.

I had weaved through well over 800 riders and finished in 8:58:11. Sub-nine and a Big Buckle!

Leaning on the railings, head in hands, it felt like an out of body experience. Nine hours earlier I’d been shivering on the start line; now I had one of the coolest prizes in amateur cycling in my hand and at that moment I couldn’t recall any of the bits in between. I did remember however, that I had a beer token in my pack ‘where’s the bar?’