GP-Monza
It's still a little while until spring. The Monza GP will bring it to life in all its colors
It is like the overture to a great symphony. A spring symphony. Ignition on, and not only the conductor’s display lights up in the most glorious colors. Rebuffini’s fittings are also brightly colored from the flanks, as if they wanted to strike their own chords. Euphony is also possible in color.
We’ll soon be driving again on a summer night, when we don’t want to have to feel for the switch for the main beam. Can’t you always have these illuminated fittings? You can’t. We’re not just standing in front of a Harley, we’re standing in front of a Thunderbike, a model from the precious GP series, and this time it’s called “GP Monza”.
The exclusive GP series
We have been building “Grand Prix” bikes for some time, once within the model ranges of our exclusive small series. Since 2018, we have been offering the GP based on the original Milwaukee Eight chassis. And we already presented our latest projectile based on the Breakout at the Custombike Show in December. Now you can see it here in full detail. So stay seated and hold on tight!
You’ll notice it at first glance: This time, Kruse-Design has given it a glossy finish. This is rare for our GPs. But this is just the beginning.
You are currently viewing a placeholder content from YouTube. To access the actual content, click the button below. Please note that doing so will share data with third-party providers.
More InformationNaturally, the Monza rolls on our large GP wheels, 23 inches at the front and 21 inches at the rear. They are monoblock wheels, milled from the solid, designed in bicolor. The GPs also have to meet our high driving physics requirements. With a width of 260 millimeters, the rear tire is almost modest in size, but this ensures directional stability because the widths at the front and rear are not too far apart. Wider would certainly have been better for show, but the Monza delivers enough show as it is.
The elegant combination of matt black and bicolor design gives the GP wheel an impressive aesthetic and sets stylish accents.
The 21-inch rear wheel is mounted in a single-sided swingarm. This is actually a technical solution from racing to facilitate quick tire changes. But it also looks impressive, especially with the large-format perimeter brake on the left-hand side. We have also found a solution to match the extravagant tire format to a functioning ABS, as we were able to relocate the encoder sensors from the wheel bearing to the hub.
And, of course, we also gave our Monza an adjustable chassis. It can be raised and lowered on command. No, not with Airride this time, because that could stamp under the acceleration pressure. That’s why we installed a hydraulic solution. This was necessary because we also gave the 117 engine more pressure with a suitable tuning. Not so much in terms of power at the end of the flagpole, by the way, but in favor of more aggressive torque from below.
Even the tank has been given its own design, of course, including the one from our GP series. Because of the components for the injection system in the series tank, tank modifications of this size are no longer common today. But we can do that too.
Complete front end from Thunderbike
The front end has been completely renovated, all by us: triple clamps milled from solid material, our own stanchions with attached GP handlebar halves, our own dip tubes with mounts for the brake callipers of the huge 340 millimeter discs. The fork can be retuned from traffic light to traffic light, because our GPs are always based on drag racing. Every start has to offer our customers the experience of a new sprint.
So much for the knock-out facts. We want to give you at least a brief look at the rear and front spoiler. You’ll be looking for screws there for nothing. Both are neatly welded in the service of a clean look. These two parts are not store items and are not listed in our parts list. Instead, we have linked the comparable bolt-on parts.
We told you: just waking up the ignition of our GP Monza makes a symphony resound. Our GP silencers will tell you what it sounds like in every movement. Their sound also has a color.
Parts & Details
Gallery

Author / Editor
Michael Ahlsdorf
Your Contact
More Breakout Customs
You can find Thunderbike Parts and original Harley-Davidson Parts in our online shop.