Camarillo, Calif., Oct. 8—Hiro Koiso of Hiro Koiso Racing had set the fastest open bike record on the salt at Bonneville Motorcycle Speed Trials at 227.236mph in 2017. The JIMS/T-Man Performance 135 c.i. Twin Cam engine is coupled with a C-1R ProCharger on a modified 2006 Harley-Davidson FXDI-based motorcycle that puts out over 400 hp to the rear wheel. This year, aerodynamic aid was put into place entering the team into the Partially Streamlined class. Following the shakedown passes from the first day, August 27, Koiso clocked a blistering 259.951 mph on the measured mile. This is the fastest speed recorded in history on a sit-on Harley-Davidson motorcycle.

The GPS recording showed in excess of over 260 mph. However, during the timed mile, the front tire began to fail. Koiso was able to keep the bike upright, but extensive damage to the bike kept him from making a record return run. “We could only make a few runs at the BMST this year. But we learned some priceless information from them. By knowing the cause of failure and what our equipment is capable of, we are going to go even faster next year.  Our next goal will be a tribute to the H-D factory Streamliner efforts from 1970, which set a record at 265.492 mph. All things considered, we believe it is possible to hit the 270 mph mark. We just need to work harder for it.” Koiso stated. We at JIMS are extremely proud to be a sponsor of Hiro Koiso Racing.


—Press release


  1. […] Bill mentions a couple things during our discussion I wanted to provide links for – the first is Bombar’s Beemers. Funny story: once upon a time when I worked at an independent BMW repair shop almost every day of the week, I answered the shop phone. Turns out is was the folks at Bombar’s calling; one of our vendors had mistakenly sent them a package meant for us. We got it cleared up pretty quickly, but I don’t know if they ever received the parts they were waiting for! Anyway, the other thing Bill mentioned isn’t a thing, it’s a person – Hiro Koiso. You should definitely check out his Bonneville story. […]


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