Up-Close with the Mugen Shinden Hachi

The 2019 Isle of Man TT once again saw the record lap drop for the electric class, with the new TT Zero record mark set at 121.909 mph by Michael Rutter, on the Mugen Shinden Hachi machine.

The Japanese squad has become a tour de force at the Isle of Man TT, taking now six-straight victories on the Mountain Course. Each year, we have seen the winning TT Zero lap time drop in number, and 2019 was no different…though barely.

Shaving less than a second off his time from 2018, Rutter crossed the line in 18’34.172″ – a figure likely attributable to the dismal weather conditions for this year’s TT gathering, which meant very little practice time for all the competitors.

Despite that lack of progress, a quick look at the Mugen Shinden Hachi shows that the Japanese outfit has not been resting on its laurels, despite the lacking arrival of a serious competitor in the TT Zero class.

The Mugen Shinden has always featured a carbon fiber chassis, though the design has evolved over the years. The use of carbon fiber has helped the race team reel in the weight on the electric superbike, which is still said to tip the scales at 547 lbs.

The use of carbon fiber serves another purpose though. Looking down the pipe on future motorcycle development, carbon fiber chassis parts are surely to become the norm.

We are already beginning to see automotive players experimenting with this technology, especially over in Europe. BMW and Volkswagen (typicalyl through the Audi brand) have already begun touting their own in-house carbon fiber projects and abilities.

One can make the argument that the BMW HP4 Race was an exercise is the German outfit showing off its carbon fiber chassis abilities, making the track bike almost exclusively from the composite. Then, there is the Ducati 1299 Superleggera…

Honda and the other Japanese brands are certain to follow suit, and thus it makes sense for a company like Mugen to be exploring the use of a carbon composite frame in a motorcycle application…and where else better to prove the design than at the Isle of Man TT?

Mugen is tight-lipped about its motor and inverter technologies, simply stating that they use a three-phase brushless motor design.

We know however that Mugen once partnered in 2014 with Mission Motors for its drivetrain needs, and at that time Mission was using a three-phase AC induction motor setup. Presumably, that same concept remains inside the Shinden Hachi.

With 163 hp (120 kW) on tap, along with 155 lbs•ft (210 Nm) of torque, there is plenty of go-power under the hood of the Mugen Shinden Hachi, but the issue again comes back to weight.

A 121+ mph is nothing to sneeze at, but now the team is reaching the physical limits of running such a heavy motorcycle around the Isle of Man TT Mountain Course.

Development on the electric drivetrain is surely reaching its zenith, in terms of finding performance parity with thermic-powered motorcycles, and now the question moves to packaging.

Finding technologies that can begin to take chunks of weight off the next generation of Mugen Shinden superbikes will be the key to improving on the TT lap times.

With the bulk of the weight in the battery pack, that is where the next gains will come from. We have already seen Mugen removing weight from the more conventional parts.

We have already mentioned the carbon fiber frame, but astute eyes will see the carbon fiber outer tubes on the Showa forks, which were first used last year on the Shinden Nana.

We have also seen those forks include air-powered internals, which further help reduce the running weight, by roughly 5 lbs

Although we still believe the lack of forward progress on the TT Zero lap record this year comes down to the reduced amount of time that riders had on course this fortnight because of the weather, we predict that the coming years will show a diminishing return for the electrics.

In order for the TT Zero lineup to take its next step forward, we will need to see a similar step in the battery technology becoming available. Solid-state batteries give that promise, offering more power in a small package.

These denser battery designs should allow Mugen to make a drastic weight reduction to its Shinden, which in turn should offer better lap times.

With solid-state batteries still two to three years out though, we have rough years ahead of “incremental” progress. Worse yet, without a proper competitor to challenge the Mugen team, the TT Zero race promises to continue to be the lopsided affair that it has become.

The silver lining in that thought is that the major manufacturers are quickly becoming aware that they need to be developing electric motorcycles. The climate is changing to favor EV development, both literally and figuratively.

Maybe, this will mean that other teams with large racing budgets will line up on the TT Zero grid next year, or perhaps the year after. We certainly hope so.