What makes it? Meaningless isolated numbers don’t make it that’s for sure. Contrary to what you might read elsewhere you don’t need specific head angles or short chainstays for a bike to be fun. Not if you don’t get everything else right. And fit, well there’s a tiny percentage of luck involved. I recently got fitted up for a suit for a mates wedding, everything was fine on sizing except the rear, and being broad in the ass there was not much he could do, and anyhow on a day when I’d no doubt be rickety of gait (a shape that comes with the business of ushering) then a slightly tight rear wouldn’t matter too much. Yet fit matters, but fit more than anything will (on mountainbikes more than road) be largely be a compromise. Sometimes bikes come in that fit well, few fit perfectly.
In terms of shape for my angles this bike is tailor made. From the 455mm chainstays to the 735mm front centre, to 28.5” downtube, the 1190mm wheelbase and the crucial 338mm bottom bracket the Stumpjumper holds you in position, it balances your ride. The 29” wheels allow for wobbly Sundays, the standover allows for body movement of any shape or kind. It does NOT have short chainstays (that part of bike alone cannot be held responsible if everything else is not in sync), but it has the perfect shape.
The Stumpy is a special trail bike. It simply tears the woods apart. OK it might be too flexy on the rear for real hard days on the Riviera (an Enduro 29” would be a better call) but for all round UK riding this bike rocks.
A year and a half in, the next chapter for the Stumpy is a new support crew in the shape of a RockShox Monarch Plus rear shock and Pike forks, carbon Specialized Roval wheels and some 2.3 Maxxis High Rolling rubber to give the bike a bit more body. Together with SRAM 1×11 this brings the weight down and takes this bike to a whole new level. Surrey better watch itself.