23 Years After its First Ascent, Will Bosi Repeats ‘Mutation’ at Raven Tor, Ups the Grade

Will Bosi is an avid climber, a formidable competitor on the global circuit, and as of October 31, the only repeat ascensionist of Mutation at England’s Raven Tor — one of the most challenging sport routes of the 1990s.

Steve McClure freed the route near Sheffield back in 1998 and graded it 9a (5.14d). Over the past 23 years, several climbers have attempted to follow McClure’s send, but none made it to the top until Bosi.

Mutation jumps a grade (or two)

Will Bosi works 'Mutation' at Raven Tor in 2018. Still: Hot Aches Productions

Still: Hot Aches Productions, circa 2018


In a testament to both McClure’s depth as a climber and Raven Tor’s famously difficult climbing, Bosi has suggested bumping Mutation’s grade up to 9a+ (5.15a). Given the nature of Mutation, which is an extension of Evolution 8c+ (5.14c), and the amount of time Bosi invested before notching the redpoint, the 22-year-old Scot says it might even go at 9b (5.15b). If future repetitions agree with the higher grade, Mutation will stand out as the world’s first 9b-level route.

Bosi, who first jumped on Mutation four years ago, spent more than 40 climbing sessions working out the moves. The young sport climber’s dedication to the redpoint is well documented on his social channel. One post from January 23, 2019, shows Bosi crimping down on the route’s potato chip-thin holds.

“Finally! This was by far and away my longest project on a route and I am so happy to clip the chains on it,” he commented following Sunday’s victory tick. “Full credit to Steve McClure on an amazing first ascent and for establishing a climb with such amazing moves.”

It’s unclear if footage of Bosi’s redpoint go exists, but the following video offers a glimpse into one of his Mutation sessions from 2018.

Steve McClure on Mutation at Raven Tor

In a statement about the line’s repeat, McClure said, “My first reaction when I got the news was ‘Awesome!’ I was so psyched for Will that he had finally done Mutation. A few years ago, I was really worried that the route was going to gather dust and not see a repeat, so it was great when Will opened his account on it…[F]or me, the route is at the absolute limit, with no margin for error. You need to have the route dialed, be in great shape and have perfect conditions, so I am really happy that it all came together for Will!”

It’s been a newsworthy and nostalgic autumn for sport climbing at Raven Tor. Late last week, 16-year-old Toby Roberts repeated Hubble 8c+ (5.14d)Hubble became the world’s first 8c+ (5.14d) when Ben Moon put it up in 1990. By no coincidence, Hubble and Mutation are neighboring routes.