One of these families is something called GT. It’s called so because the base models used, FXDRs, always use the same kind of Thunderbike-made custom parts, but only employed differently enough to make each bike stand out as unique.
We stumbled upon the first two-wheeler in the GT family back in 2020, when the FXDR One came to light. Then came the GT Style, the GT-3, GT4, and GT-4, all of them potent visual manifestations of the Germans’ talent.
And here we are today face to face with the most recent member of this Thunderbike style of bikes, the GT-6. It too an FXDR in origin, it is also the only one so far to be mostly black in appearance - the others are all colorful builds, but in a very visually organized fashion.
The GT-6 is a real treat to look at, miles away from what it looked like when in its original form. That’s because close to 40 parts have been changed for aftermarket pieces on this thing, amounting alone (that is not including man hours, paint job, base motorcycle, and so on) to a total of 21,300 euros. That is close to $23,000 at today’s exchange rates and about as much as it went into the other Thunderbike GTs we’ve discussed in the past.
The single most expensive part included in this build is the single side swingarm kit, priced at $5,600, but it came as a required change for the design of the GT-6 to work as intended. At the opposite end, a modified, lowered fork was fitted.
Thunderbike does not reveal the size of the custom wheels fitted on the machine, but judging by what the others had on, we’re probably dealing with ones sized 23 inches at the front and 21 inches at the back. They are both assisted in keeping the motorcycle upright and visible by an air ride suspension system ($1,600).
All of the above are the biggest and most expensive elements fitted on the GT-6, but the list of changes also contains numerous covers, the handlebar with heated grips, and the motogadget mirrors and turn signals - these, together with the tires (Avon Cobra for the front and Metzeler Cruistec for the rear), are the only parts used that are not made by Thunderbike themselves.
As one of the most complex customs we've seen in a while, the Harley-Davidson GT-6 only has us hoping more of them will make it into this world soon.