Curry Racing's Custom-Built GSX-R750 Powered Hillclimb Bike

February 26, 2020 / by Paul Olesen

Take a dive into Curry Racing's custom-built GSX-R750 hillclimb bike powered by Wiseco pistons.

 

The Curry Racing Team’s custom-built Suzuki GSX-R750 powered pro hill climb bike is a powerful machine that is not to be piloted by the faint of heart. Johnny Curry, the bike’s owner and builder, set out to develop a bike that would conquer the steepest hills with ease, and ultimately, prove victorious on the professional hill climb racing circuit. Johnny was kind enough to share technical details about the bike, and we wanted to take this opportunity to showcase the impressive build that transpired.

Curry Racing Hillclimb Wiseco 5
This custom GSX-R750's power must be respected when facing the hillclimb challenge at hand.

Like many successful racing programs, the development of Johnny’s bike has occurred over time and slowly evolved as the team has learned from successes and failures throughout the racing seasons. At the bike’s inception, the frame was built around a stock 2005 Suzuki GSX-R750 engine. The stock engine served its purpose propelling the machine at numerous hillclimb events, however, eventually tired and blew. The engine failure was the catalyst for acquiring a brand new engine and fitting it with Wiseco high-performance forged pistons. The choice to use Wiseco pistons was easy for Johnny. Over the years, Johnny has had the opportunity to run and test various stock and aftermarket parts in his quest for the podium. In his experience, no other components or pistons have ever held up as well as Wiseco.

Curry Racing Hillclimb Wiseco 4
Even with the additional performance, the four-cylinder engine is still pushed to its limits in hillclimb. Johnny Curry turned to Wiseco for forged pistons to aid in reliable power.

In need of some performance pistons for your machine? Search it here.

Engine Selection

In hill climbing, power and torque are both key contributors that determine how well an engine will work in competition. The Curry team selected the Suzuki GSX-R750 engine because it delivered ample power and torque out of the box. They also felt that Suzuki had had an exceptional track record of providing its customers with reliable and powerful engines, making the GSX-R750 engine a stable base platform to develop from. The addition of Wiseco’s high-performance forged pistons enhanced the engine’s robustness even further.

Just listening to this 750 beast rev is both intimidating and enticing.

In combination with the raw power the GSXR engine provides, gearing the machine correctly is a critical aspect of a successful race event. The Curry team spends a significant amount of time developing and testing the best combination of gearing for different hills and soil conditions. When the gearing is set up properly, it allows the engine to operate at peak power over the expanse of the hill, which is a key to climbing the hill as fast as possible.

Fueling

Over the years, Johnny has tried and tested many different kinds of fuels. What he ultimately found was that when it came down to it, the best was just regular high-test pump gas. Johnny says, “other fuels just didn’t want to flow right and always gave us problems with our fuel injectors.”

Curry Racing Hillclimb Wiseco 3
Gearing can make or break a hillclimb run as it determines what RPM range the engine is operating in throughout the hill. Fine tuning for each venue plays a key role in successful runs.

Custom Chassis

According to Johnny, the goal of the chassis build was two-fold, to optimize performance around a well-proven chassis and to maintain the stock look of the bike. The frame is built by “Dirty Dan,” a well-known chassis builder for pro hill climb bikes. It is entirely custom down to a T. The chassis is Dan’s third GSXR build, of which it is the smallest he’s ever built. Over the years, the design has been updated to keep up with the ever-changing appearance of the new bikes sold by Suzuki. In its current trim, the bike takes on the look and feel of a 2014 RM-Z 250.

Curry Racing GSX-R750
This hillclimb machine's chassis is completely custom, built to house the GSX-R powerhouse while maintaining a modern RM-Z dirt bike look.

Suspension

The impact of an optimized suspension setup has evolved on the hill climbing circuit. According to Johnny, “in the early days of the sport, everyone ran relatively stiff suspension setups.” Since the inception of the IRC Motoclimb Super Series, suspension setups now encompass the entire spectrum of configuration options. The Curry team’s suspension preferences are proprietary to them and something they prefer not to discuss in detail.

Tires

In hill climbing, a variety of conventional tires, chains, studs, and paddle tires are installed on the rear tire to enhance traction. The Curry team has had the most success using a combination of chain and tire to propel their bikes up the gnarliest of hills. Tire and chain selection are taken very seriously because the combination of the two is ultimately what transfers all the power to the ground. Many teams use heavy chains; however, the Curry team often selects the lightest chain possible. Doing so keeps the inertia of the rear wheel to a minimum, which allows the engine to operate more consistently in its powerband.

Curry Racing Hillclimb Wiseco 2
Curry Racing chooses a combination of a light chain with a hillclimb tire to handle the traction responosibilities.

Racing Success

The Curry Racing GSX-R750 has seen multiple successes over the years and racing seasons. Most notably, the Curry team has won a national title and had multiple top-five national title finishes over the years in the pro series. While the bike hasn’t been entirely trouble-free (nothing ever is), the Curry team has never been inclined to switch platforms. Instead, they feel that with more hard work, time, and effort, they can continue to be very competitive.

poags hole hill climb Curry Wiseco

Future Modifications

No racing bike is truly ever finished, and in this case, Johnny has plans to make additional engine modifications. Johnny would like to find a 2016 or newer Suzuki GSX-R750 engine, which is smaller and lighter than the earlier models and further increase power by adding a supercharger. To retain the high-performance and durability he already achieves, Johnny wants to utilize Wiseco forged pistons to ensure the top end can handle the increased power.

Johnny also intends to introduce his youngest rider to the bike, Bryan Curry, who is 14 and competes in the amateur series. Bryan has a ways to go before he’s ready to compete in the pro class. However, Johnny hopes that by introducing him to the custom-built GSX-R750 bike at this stage, Bryan will learn how to ride it and be a feared competitor in the pro class when his time comes.

Curry Racing Hillclimb Wiseco 1

Topics: featured, Powersports, BIKE FEATURES

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