Lattice Blog

Will Bosi: Sends Burden of Dreams (V17/9A)

If you’re a climber, you’ve probably heard the news! Will Bosi sent Burden of Dreams (V17/9A), commonly speculated acorss the globe as the world’s ‘hardest’ boulder problem!

But… who is Will Bosi… and what is Burden of Dreams?

Who is Will Bosi?

Will Bosi is one of our athletes here at Lattice Training, but not only that, he is one of the UK’s top sport climbers and boulderers.

Will Bosi comp climbing in his early career

His early career was in competition climbing; he’s a three time IFSC World Cup Lead Finalist and a former member of the GB Climbing Team. More recently, Will has turned his attention to climbing feats outdoors, collecting an assortment of sends in the 8B-8C+/V13-V16 (boulder) and 8c-9b/5.14a-5.15a (sport) range!

Prior to Burden of Dreams, his most recent achievement was back in November 2022 when he claimed the third ascent of one of the few other V17/9As in the world: Alphane in Chironico, Switzerland. This made him the 5th person to ever climb the grade.

What is Burden of Dreams?

Burden of Dreams (a.k.a., Burden, BoD, BOD) is known as the hardest boulder problem in the world. The climb is located in Lappnor, east of Helsinki, Finland.

Nalle Hukktaival made the first ascent and established the line in 2016 after working the problem for three years. He graded it as V17/9A, making it the first boulder at that grade.

The climb is a 45 degree angle boulder that moves through tiny crimps and crystals.

The V17/9A Replica

Earlier in 2023, fellow pro-climber, Aidan Roberts, scanned the holds on Burden of Dreams and had replica holds made by Core Climbing. The replica problem was set at Lattice HQ where Aidan and Will spent 10 days projecting the climb.

After linking the problem in approximately two halves, Will travelled out to Finland in March.

Aidan Roberts on the Burden of Dreams replica at the Lattice HQ

The Live Stream

Will live streamed his first few sessions. On his first day, Will managed to do all five individual moves within half an hour: the top moves first and then the lower section.

In between attempts, Will compared the climb to the replica, stating that some moves felt easier, some moves felt harder than on the replica. He said that the friction on the rock was better and that the holds are closer together on the real thing.

On the 12th April 2023, after 24 days working the problem (replica and boulder time combined), Will Bosi sent Burden of Dreams on his first attempt of the day in his fourteenth session.

This made Will the third climber in the world to have sent two 9A/V17 boulders. Shawn Raboutou and Simon Lorenzi being the other two. He is the first person to repeat two established 9As. Will previously climbed Shawn’s Alphane (9A/V17) in Chironico, Switzerland in November 2022.

After the send, Will said “It feels unbelievable right now! I came to the boulder today thinking it would be too hot to climb but the warm up felt incredible and on the send I flew through the bottom section and after dropping the top hold previously, this time it all came together!”

On the grade of the problem: “From the overall experience on this boulder from working
the replica to finally sending it, I think it’s a step up from everything else I have done and
it is a huge step up from any 8C/+ I’ve done. Therefore, I think it definitely deserves 9A!”


Highlights: Tom Randall Interviews Will Bosi

Tom: How do you feel about sending Burden of Dreams, the world’s hardest boulder? It must be an important part of your climbing experience this year, potentially your whole career?

Will: Definitely. Other than Mutation (9a+/5.15a), which was almost a comical project, this is the longest I’ve had a project, by far the longest boulder project. I’ve definitely invested the most amount of time into it. Also, it’s kind of that mythical problem. I remember when Nalle sent in back in 2016. We were watching it, super psyched, but it was so, so far removed. Back then I was thinking, you know, maybe I’ll see it one day. Even last year, I wouldn’t have considered I’d ever be able to claim this boulder. Actually sending it seems completely ridiculous to me.

Tom: What did you do to celebrate?

Will: Champagne and steak!

Tom: Do you think that this is problem is an ‘on demand’ problem for you now?

Will: Yeah. It’s weird to say that but this is one of the few climbs that I actually get training on whilst trying it. Most times I go try a project [on a long trip], you feel like you’re doing well, because you’ve learnt it really good. But you feel like you’re losing power and you need to go back and train. [However, on Burden,] every session, I feel like I’ve gotten a bit better on each move and a bit stronger. The second time I fell off the last move, I did the first move hitting three fingers… and then somehow, I did the second move on three fingers! Which when I first started trying felt completely impossible. I feel fairly confident saying, if I was to take some rest, I could do it again in another session. I, equally, could just not do it, because it’s low percentage, but I think the moves are getting better and better. I think my biggest streak was doing the first move nine times in a row without dropping it over four sessions. And at the start, just doing the move by itself was complete limit.

Tom: What was harder, Alphane (V17/9A) or Burden of Dreams (V17/9A)?

Will: They’re different boulders for sure, as a first thing, but I think Burden of Dreams was harder, at least for me it was definitely harder. It took more than double the days and a lot of work.

Will Bosi on Alphane

Tom: Could you have done [Burden of Dreams] this trip without the replica?

Will: No, the replica training was absolutely crucial to sending Burden of Dreams this trip. Because, it [the replica] was so good. I think it basically gave me an extra 10 sessions. If I’d had to wait an extra ten sessions from now, I think I would potentially still have a shot, but I think the weather would get too hot and I’d have run out of time.

Tom: Can we talk about your dad’s finger strength?

Will: I wish we had done a Lattice test with him! He doesn’t climb anymore. He climbed for a short period a couple of years ago, when he was around 60. Then, it all clicked in my head and made a lot of sense. Because his technique was absolutely awful. But, six weeks into climbing he was dragging himself up 7a’s. Grabbing ratty little footholds and yarding to the next one. I’d be watching him like… JUST USE THE HOLDS! I think the thing I got from him genetically is that he’s very, very, very motivated. If he sets his mind to something, he’ll commit to it until he injures himself… which is basically what he did with climbing. I think his finger strength is inherently good and that’s definitely helped me.

Tom: I want to test an elite athlete’s memory: What was your sport grade and what was your boulder grade at 16 years-old?

Will: Bouldering, I think I did 8B+ at 16… I skipped a grade… so at 15 I had only done 8A. Sport grade… I climbed Rainshadow (9a/5.14d) at 17, when I was 13 I did 8b+… so… 8c?

Tom: No! You were still stuck on 8b+!


Want to know more about Will Bosi and Burden of Dreams, the world’s hardest boulder problem? Listen to the full interview with Tom Randall.

Follow Will on Instagram.

Follow Lattice Training on Instagram.

Leave a Reply

Your email address will not be published. Required fields are marked *