Neko Mulally transforme son vélo DH en … 29″

C’est sur sa page Instagram qu’on vient d’apprendre que Neko Mulally, pilote pro de DH du team Gstaad Scott, vient de tenter une expérience inédite en transformant son bike de DH 27.5″ utilisé en compétition en 29″. Même si cette idée n’est pas nouvelle, Neko Mulally a le mérite de passer le cap!.

Ma première impression est que tous les chocs sont plus « atténués ».

Built this thing up with a few mods to the bike I've been riding all year. Started by fitting 29" wheels to the frame I raced at world champs. To get the BB low enough with the larger wheels I switched from a 240mm shock (9.5×3) to a 222mm shock (8.75×2.75). The difference in shock size was more than I was looking for, so I put offset bushings in both ends of the new shock to make it less of a change. The shorter shock made the bike too slack, so I put in a +1 degree headset. The front wheel fit into my standard 27.5 fork, but had very little clearance so I milled out the fork arch a few extra mm for a smooth fit. The rear wheel fit with plenty of clearance and has room away from the seat tube at bottom out. I had to run my seat post a little higher than normal and push my seat all the way forward on the rails. Other than that everything else fit perfectly. The BB height is 340mm, head angle about 62.5 degrees, the wheelbase about 1260mm. My first impression is that it makes all bumps feel smaller. The shorter shock cut off the top of my stroke so it feels less supple than riding my normal set up. Turning is not too bad, but feels kind of 2 dimensional. If you get late into a turn you really need to commit or you get stood up. It definitely is not as nimble with the big wheels, but when you ride smooth it's great. Then switching back to the 27.5 the front wheel seemed small after riding this thing! For a bike that I was able to build into another wheel size with all stock parts (aside from the linkage I've been using all year) it feels pretty good. I'm not sure better or worse yet, but it certainly has its sections and I'm excited to ride it more. I think there is huge potential for a downhill bike designed from the ground up around 29" wheels. It could be a great tool for certain tracks, maybe more than you would think.

Une photo publiée par nekomulally (@nekomulally) le 31 Oct. 2016 à 3h55 PDT

Pour cela, Neko Mulally a du réaliser quelques modifications techniques poour adapter les grandes roues sur son Scott Gambler prévu en 27.5″ : augmentation de l’angle de chasse d’un 1° via la modification du jeu de direction et adapter l’entraxe de l’amortisseur pour passer de 240mm à un 222mm. Résultat, Neko Mulally semble assez satisfait de son expérience en 29″ et pense aller plus loin dans ses essaies…Si ses retours sont pris en compte, cela devrait faire des émules chez certains!. A suivre donc…