[Hide Comment] Jumbo was put up by Pat and Rick Thompson. The grade is definitely 10d.A lot of people who climb at Shelf a lot agree with this grade. Mar 19, 2002

[Hide Comment] Montay - with all due respect for your opinion, the consensus grade for this route is 10d. Since the American grading system is rather vague in many regards (i.e. - variables such as body size and reach, level of fitness, experience, etc.) it at best serves as an approximation of difficulty. That is why a consensus grade, which is defined as the grade generally agreed upon by the majority of climbers, is so important when characterizing the difficulty of any particular route. While we will always see debate in the climbing community about the respective grade of a given route, particularly new test pieces (which this certainly isn't), a trade route such as this one becomes recognized by local climbers as a particular grade, and generally that grade becomes published consensus grade. In this case, the subject route has been repeated hundreds of times, and from those ascents the consensus grade of 10d has emerged.

When one compares the difficulty of this routes to other routes of its grade it seems to measure up quite respectably. For example, it is noticeably more difficult than its companion route, Love Pump (10b/c), and compares quite favorably to Turbo Charged, Inter-cooled, Meat Machine (10c/d), Menses (10d), and Slender Fungus (10d). I suspect that is why people call it 10d. Apr 1, 2002

[Hide Comment] Funky side pulls from the start, straight forward at the top. A fun climb that's worth doing. Mar 17, 2003

[Hide Comment] Enjoyable side pulling with a thin left foot move at the crux around bolt three. The route is bolted extremely well and, in fact, watch out for the z-clip action between bolts three and four. There is a seventh bolt before the anchors which is nice because, although the climbing is significantly easier up there, it's a pleasure to have the protection. There's also a sweet right-hand hand jam at the last bolt before the anchors. Oct 19, 2005

[Hide Comment] Wow, very tricky route for the grade. Seems like the consensus emerged as a sandbagged route- at least for Shelf grades. My partner and I successfully climbed several routes 11c and harder all weekend, but both of us fell off this one at the crux high step. Then we both easily onsighted 13 Engines to the left at 11c. Not sure what happened here, but I felt JPL was one of the hardest routes I did all weekend. Maybe it is the Gallery area. I also thought Slender Fungus (10d?,11b/c?) was harder than several other 11c routes at the Bank I did the day before. Certainly harder than Unusual Weather at 11c. The grades don't matter to my experience and enjoyment, as all of these are wonderful climbs. I am just starting to question the grading continuity among the various crags at Shelf. Nov 10, 2008

[Hide Comment] For what it is worth, I will add my rating of 10d to the consensus. It is just a little tricky with the side pulls. Exciting route. Jun 14, 2009

[Hide Comment] This is IMO a better route than its neighbor 'Love Pump'. Both are worth doing, but JPL has some memorable climbing. Jan 10, 2012