Neko Mulally to try racing downhill on 29″ wheels next year?

Benjamin Haworth

The shape of things to come?

Neko Mulally’s latest Instagram post showing a Scott Gambler modified to take 29″ wheels has got folk talking.

>>> How to convert your 29er to a plus bike

The racer, perhaps best known for racing without a chain, says “I think there is huge potential for a downhill bike designed from the ground up around 29″ wheels”.

29ers haven’t really been contemplated for World Cup level DH racing very much. Mitch Ropelato had a few runs on a Specialized Enduro 29er a couple of years back on some more pedally and calmer courses but that’s about it.

The general viewpoint is that the wheels aren’t stiff enough, the handling isn’t nimble enough and – most importantly – it’s nigh on impossible to fit in long enough travel suspension into a 29er bike. 29ers seem to max out at 160mm of travel.

This is his original post..

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.

A post shared by Neko Mulally (@nekomulally) on

What does it say?

Long captions can be hard to read so we’ve pulled it apart so it’s easier to take in…

“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.”

So how does it ride?

“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.”

Comments and questions

The piccie has already provoked a lot of questions.

When asked about what he thinks of his new Frankenbike’s bar height, Neko replies: “I let the air out of the fork and pushed the sanctions through as far as the wheel would clear the crown at bottom out. With my zero rise Deity stem I don’t feel any problem with bar height.”

When asked what tyres are on there (29er DH rubber is pretty rare), Neko replies: “They are [Schwalbe] Super Gravity Magic Mary. Maybe DH casing some day!”

Why has he done this?

In a word: speed.

Downhillers will try anything to get another few hundredths of a seconds quicker. A significant amount of enduro racers – and almost all XC racers – are on 29ers, so it’s hardly surprising to see modern big wheels being tried (again) in Downhill.