Part 3 of Project Ninja Turtle: 300R Handlebar Conversion

If you’re going to build a streetfighter, especially a Ninja streetfighter, you need to have a bad ass handlebar that instills fear into the enemy the way a policeman’s nightstick makes a purse snatcher pee his pants. You have to be able to throw your elbows up and muscle your bike into corners and slides the way a matador grabs a bull by the horns.

To do that, you need a tough handlebar that makes you forget about the wimpy, stock risers the bike came with. These risers are basically a Steve Urkel version of what a handlebar would be if it wasn’t made by Renthal. The Renthal “Street-Fighter” bar is perfect for transforming the 300R into the streetfighter who can Hoo-doo-kin! his competition to tears.

We approached Renthal with the idea of building the Ninja Turtle and of course they were on board. Who doesn’t want to see David beat Goliath? Thanks to Renthal, we were able to acquire the “Street-Fighter” handlebar so you could see first hand how we did a seemingly impossible task in a just a few hours.

The Transformation

The stock handlebar risers had to go. Riding a 300 with these is like watching a T-Rex make a bed. Just sad.


We used KX250F OE handlebar clamps to fit the Renthal Street-Fighter handlebar to the Ninja 300R’s stock upper triple.


First thing’s first. To remove the stock handlebars, we had to first remove the left and right hand handlebar switches, the brake lever, perch and throttle grip.



To keep track of the screws for the switches, we left them in the switch assemblies.


Since the bar end had never been removed before, we tried to remove it using an impact, but eventually had to turn to the torch to get it off. Say bye bye bar ends!



We removed the clutch lever, perch and left side switch.



Lastly, we used compressed air to remove the left side grip.


With everything removed from the risers, we were able to take them off by removing two bolts on each side.


Now that the upper triple was bare, we finally had to chance to figure out how to install the Street-Fighter handlebar without weakening the triple.


We decided the best way to do it would be to use the upper two holes that were already there for the risers. This way, the Street-Fighter handlebar would be centered on the upper triple and we wouldn’t have to drill any extraneous holes.


Next we removed the steering stem nut and loosened the upper triple fork clamp bolts. Please note that to remove the triple, you have to turn the forks to the side to allow the ignition switch to clear the steering neck.


The bummer was even though the triple was free of the forks, the ignition switch was still connected. The ignition switch connector is located underneath the gas tank, so we had to remove the tank to disconnect the switch and remove the upper triple.


We used a mill to drill the holes for KX250F bottom clamps into the 300’s upper triple. Unfortunately, the mill doesn’t come with a jig for these sorts of things, so we had to make one.


The bolts attached to the KX250F bottom clamps measured at .470’’, so we matched a 15/32’’ drill bit to that size for a precise fit between the clamp and upper triple.


Watching the mill do its work was as entertaining as seeing a shoe hit George W. Bush in the head. We loved it.


As you can see, our measuring paid off. A perfect fit!


Now for the other side…


With the bolt holes drilled, we de burred the edges with a de burring tool – A classic machinist’s trick for a clean finish.


After we installed the clamps, we noticed the bolts were too long. In most other cases a long bolt would be considered an endowment, but in this case it was an impediment. How do we make it so we can tighten the clamps to the upper triple with the bolts that we have?


Before we continued machining, we made sure that we could fit the bars to the clamps with the holes that we drilled and still clear the ignition switch.


Luck is on our side. Our machinist happened to have an extra piece of stainless steel we could use to make spacers for the bottom clamp bolts. Using a lathe, we peened a hole into the steel so when we connect the drill bit, it can drill a hole to just exceed the diameter of the bottom clamp bolt.


After a little sharpening, we installed the drill bit into the lathe and drilled a hole into the steel deep enough to match the length of the spacers we needed.


We measured the sections of steel and cut the spacers to our desired length.



Once the two spacers were cut, they’d take some fine tuning to clean up the finish.


Using a belt sander, we cut a notch into each spacer so they’d clear the bolt holes for the wire/cable routing brackets on the under side of the upper triple.


See! Perfect fit! Now we can tighten the clamps.


Before re-installing the Street-Fighter bar and upper triple to the forks, we had to install the bar to the triple off the bike and tighten the clamps to make sure they were straight.


We installed the upper triple with the handlebar on the forks and had originally thought about cutting the Street-Fighter bar shorter, but after comparing the length of the stock handlebars to the Street Fighter bar, we determined that the length was the same. We needed all the room we could get to reinstall the levers, grips and switch assemblies.


Next we had to drill holes in the Street-Fighter bar in order to reinstall the switch assemblies. We were able to measure the exact length and spot where the holes needed to be to reinstall the switches just as they were before.


We removed the handlebar and used a center punch to punch a divot into the bar for the drill bit. If you don’t do this, it will walk around the drilling surface and do more damage than good.


Using a drill press, we drilled the holes we needed into the Street-Fighter bar. We had to sharpen the bits, as the bar’s hard exterior was putting up quite the fight.


With all the machining complete, we reinstalled the Street-Fighter bar and put the bike back together. It came out so awesome! The handlebar install is so clean it looks stock, with the exception of the open holes in the upper triple, but we can fix that later.


Just one hiccup. We had to reroute wiring and cables to get the switches and levers to fit with the new handlebar. Unfortunately, our Ninja Turtle is an ABS unit, which presented quite an issue with the front brake hose. It was way too short. We tried to route the hose behind the triple, but with a few turns of the handlebar, the hose was already cut from being pinched against the plastics and it was also binding behind the triple. We’d play with it for the rest of the day, but it became evident this is going to take some research. Stay tuned to see how we resolve the brake issue.


What’s Next for the Ninja Turtle?

Unfortunately, we are left with a few minor problems after installing the handlebar. With the brake hose from the front master cylinder to the ABS unit being too short, we’ll need to find a longer brake line that will not only work with the ABS, but be long enough to reach the master cylinder while being safely routed with no danger of binding or tearing. In short, the Ninja Turtle needs different brakes.

Also, we’re now on a mission to find a set of bar end mirrors that can be adapted to fit inside the Street-Fighter bar’s uniquely smaller interior.

A Little About the Renthal “Street-Fighter” Handlebar

se-road-1The “Street-Fighter” handlebar (part # 789-02) is a new bar by Renthal that is designed with a bend specifically designed for street bikes and equipped with a cross brace and bar pad for a dirt-bike look and feel. The handlebar has a 7/8’’ or 22mm external diameter and fits most standard clamps and controls.

The Street-Fighter handlebar has a shot peened finish in an effort to prevent breakage or failure due to fatigue. The bar is made from 7010 T6 Aluminium, a developed alloy specifically used by Renthal to manufacture handlebars. This high-impact material has the strength of Edward’s diamond skin, which was evident when trying to drill holes for the handlebars switches. The strong material of the Street-Fighter bar is as durable as it is thick to provide some serious dampening against vibration.

The bar also has other features that are beneficial to the rider. The left side of the handlebar is knurled on the grip end to better adhere the clutch-side rubber grip to the bar surface. At the center of the handlebar is a laser etched positioning grid which really helped us to position the bar where we needed once the job was done.

List of Mods So Far

Competition Werkes GP slip-on exhaust, Competition Werkes Fender eliminator kit, Renthal 7/8’’ Street-Fighter handlebar with KX250F handlebar clamps and custom machined spacers, rreen adjustable levers (from China)

Special Thank You to Sam Rothschild

196178_3089152122493_1530828056_nWe couldn’t do this installation with the tools we had in our garage, so we had to take the Ninja Turtle to “Sam’s Man Cave,” a code name for the extremely well equipped domicile of our brother-in-law, Sam Rothschild.

Sam races an H4 Honda CR-X with Southern California NASA or National Auto Sport Association at tracks like ButtonWillow and California Speedway and he turns lap times most motorcycle road racers only dream of. He is also a driving instructor for NASA Pro Racing. Sam finished 5th in points out of 18 racers for the 2013 season.

Sam is not only a driver, but he is also a very gifted machinist and fabricator. The guy even makes his own wiring harnesses for crying out loud! He also made a custom stunt cage for our 2010 Kawasaki ZX-6R. We’re very grateful to Sam for his help with all the random projects we drop in his lap. Of course, bringing a case of beer always helps to make up for the time we take him away from his race car. Thank you!

If you’d like to see Sam drive, click here.