Exclusive: 27.5" Nukeproof Mega AM and TR

When UK-based Hotlines resurrected the Nukeproof brand, one of the first bikes they released was their Mega trail bike. Named after the Megavalanche mass-start DH race it was designed to compete in and built to cope with the ugliest conditions on the mountain, the Mega was a fairly unique bike at the time. Well before the current fashions for "enduroing," "enduro rides" and everything else with the E-word slapped in front of it, the 150mm platform came ready to be ridden hard with big bars, big tyres and 1 x drivetrains.

Last year they split the line in two, with the AM version carrying on the heavy-duty lineage and the TR version offering a slightly shorter travel, more playful take on the bike. For 2014 the line is evolving again, this time to take on bigger wheels. As their brand manager, Alastair Beckett (some of you might remember him as Ben Reid's former WC mechanic), explains, "Pretty shortly after we finished splitting the Mega into two bikes instead of one a lot of questions started being asked about the bigger wheelsizes... We're not one to jump on bandwagons, partly because we don't have the resources, but we quickly learned that this had the potential to gain some recognition in the market. Shortly after that we began testing larger wheels on a variety of frames and components. A lot of manufacturers were beginning to discuss 27.5”/650B and that helped us find the direction that we wanted to approach it from. That was around two years ago and we were fortunate enough to be able to produce our first rideable sample Mega 275s around ten months ago."





Going Bigger

Pushing Ali on what it was that convinced them to take the jump to the bigger wheels he recalls,"It was the general feel we got back from it immediately. We did a lot of testing with 29" wheels as well as we knew it would take time to get our 27.5” prototypes ready. Initially we tested a hardtail, we spent a lot of time on that and immediately we could feel the difference. When we did back-to-back testing on a similar hardtail, we noticed the advantages straight away. Every one of us that got on it could feel the benefits and the further we got down the line with testing and trying things out the more comfortable and confident we began to feel. We hadn't made the commitment at that stage as to which wheel size was right for Nukeproof, but as we went further down the road of testing we couldn't find any significant flaws with 27.5”. It was extremely important to keep the same feel and geometry as we had with the 26” Megas and if we have to sacrifice that because of the wheelsize then it wasn’t going to be the right thing to do. When we started looking at the drawings and the geometry, we quickly realised that we could get exactly the geometry and ride that we wanted with the bigger wheelsize, so it was a win-win situation. As we went further down the road with test riders, like our enduro racer Toby Pantling, we have received nothing but positive feedback all the way."




Changing Geometry


Of course putting bigger wheels in a bike isn't as simple as extending the chainstays and fork. To adapt the Mega they have had to change every single tube in the frame to take the extra inch and a half wheel diameter. There are three main areas they focused on to get the bike feeling how they wanted it to. First off is the bottom bracket height, the magic number they hit upon is 13mm drop, which is the gain in axle height on a 27.5" bike compared to a 26" bike. This means the effective bottom bracket height remains unchanged. 5mm were taken from the headtube of each size to keep the bar height the same. Finally they had to extend the chainstays from 430mm to 440mm to provide tyre clearance. From the longer chainstays they found additional, unexpected benefits. Because the bike tends to carry slightly more speed with the bigger wheels, this offered more stability and grip without any trade-off in handling that they could find. This is something that surprised Ali, going against his usual preference in bikes, "I normally like a shorter chainstay, I like that playful feel you get with them. I've been riding the TR for a long time now and it feels exactly how I want it to, not too long or too short, it's almost exactly as long as our downhill bike, but it doesn't feel like that at all. We were a bit lucky with having to push the stays out and finding that extra stability. All of our test riders have noticed the extra stability as well and are all very happy with the handling."


For 2014 the Mega AM and Mega TR will be available in both 26” and 27.5” frames, while the complete bikes will be available in 27.5” only. Complete bike specs and pricing will be released at Eurobike this year.

www.nukeproof.com