Here in the Philippines, the Yamaha DT motorcycle is practically synonymous with enduro riding. In fact, many locals in the provinces call any enduro bike a DT, regardless of make or model. It's much like how Pinoys call toothpaste “kolgeyt (Colgate)” or film Kodak when buying at the store.
In the US, the boys of Yamaha Racing have developed a DT-inspired flat tracker. It's powered by a Yamaha MT-07 CP2 (cross-plane, 2-cylinder engine) and thus, dubbed the “MT-07 DT”.
So what exactly is the MT-07 DT? Simply put, it’s a purpose-built chassis with a production-based Yamaha MT-07 engine. Multiple road race champion, Tommy Hayden, who heads the program for the Estenson Racing team, goes into a little bit more detail of how they built it within the rules of American Flat Track’s AFT SuperTwins class:
“From a chassis point of view, it’s really similar to MotoGP; pretty much everything is a prototype,” Hayden explained. “In particular with our bike, we have made to our specification every piece of the chassis with very few restrictions per the rules. Whereas the engine, I would say it’s similar to World Superbike. It starts off as a production engine, but there’s very little production about it when we get finished with it. Even the parts that are not replaced are heavily machined and changed. The displacement is changed. Pretty much besides the shell of the engine cases, everything else is changed or modified.”
They then went about developing a head with some help from Vance & Hines, cams by WebCam, and velocity stacks designed and made by YMUS. For the exhaust, they tested several pipes and settled on a Graves MT-07 pipe, which provided to return the best all-round performance. They started off with a 700cc, the standard size of the regular MT-07, before eventually boring it to close to 750cc.
“That project turned out really well,” McCarty said. “The G&G guys used our engine setup and there are a number of guys that ran Yamahas that bought those parts from us, and then had a lot of success with them in terms of consistency, reliability, all of those things. So that kind of led us to the next thing.”
The DT-07 dirt tracker concept bike was unveiled as planned at the 2015 AIMExpo in 2015, complete with a Kenny Roberts replica paint scheme. It definitely turned a lot of heads with its looks, especially with the growing trend of street trackers. As far as a race bike goes, there was more work to be done. YMUS then took it back in-house and started readjusting some of the things that were off on the geometry.
But, unlike in road racing, things can get pretty difficult in developing a flat track bike due to the sudden change of racing conditions. “I think what makes developing the flat track bike more difficult than let’s say a MotoGP or superbike is that the conditions of the track change so much and so fast,” Hayden said.
“When you’re testing, it’s really hard to measure your gains and to really be confident that you’re making things better or worse, that it’s not the track changing. Literally in 10 minutes your racetrack can be a second slower if it’s too wet or too dry or a new line develops. Then there’s the types of track that vary so much. From the little, bitty small tracks to Mile ovals to some of the TTs with the jumps and different things.”
Though there are very little specifics revealed on this build, we could just imagine the sleepless nights and the amount of effort put into building the MT-07 DT from ground up.
Flat track racing in the Philippines
Flat track racing is arguably the oldest form of motorsport racing, which started in the early 20th century when dedicated asphalt raceways did not exist yet. Here in the Philippines, flat track racing was a popular past time sport in the '60s up to the early '70s, and was often called “scrambling,” taken from the popular scrambler motorbikes used at the time. During recent years, flat track racing is once again gaining popularity, thanks to organized flat track races like the Keep it Dirty event by our friends from Cafe Racer Philippines, and the Pinoy Flat Track series by riding coach, Mel Aquino.