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Protaper fatbar conversion

Joined Sep 2017
595 Posts | 121+
Lansing Mi
Motocross protaper fat bars and protaper risers, what I learned.

First, the OEM risers on the hyper 821/939 base bike are 7/8 design and the bolt that attaches them to the triple tree is 10mm. The replacement protaper billet fat bar risers use a 12mm bolt. I ended up drilling out the rubber mounted bushing to accommodate the new 12mm bolt. This left plenty of meat around the bushing to provide support. In the future I could search out(or make) a rubber mount delete kit which fixes the risers directly to the triple tree ridgedly with no rubber mount(I found a couple people who already make them).

The OEM risers are very tall, the protaper are very short. This had me a little worried and thinking I might need to add some spacers to get the bars up to OEM height(I like OEM height). As it would turn out, the CR high bars more than make up for the lost distance. Looking at them side by side they are almost exactly the same but measuring them assembled and upside down the protaper set up was slightly taller. Now, I'm no expert and I probably would never noticed but the shorter risers seem like they would flex and twist less than the OEM set up but I don't know and I don't really care.

Next issue, the master cylinders I'm using are billet IRC masters and they are almost twice as thick as the oem. This is an issue because the actual amount of space that you can utilize for the controls is very limited. The only way to make it work was to flip flop the right master and on/off switch. The on/off switch is now slightly on the bend of the bar. Not a big deal, I might seek out fancy buttons on the future. I know a few companies like ducabike and jetprime make billet assemblies that just plug n play and can even be mounted on the master cylinders in place of their end cap.... But they can get expensive(not to mention I know of someone who makes fancy clutches and is talking about making a switch assembly as well..).

Next hurdle, because my bike is a base bike and it had an axial front master cylinder I needed to make an axial to radial fitting to make the brake line accept the billet IRC master. With the old bars it was not much of an issue. The fitting did hit the bars but it all tucked together nicely. With these protaper bars I needed to reroute the line over the top of the triple tree. Not a big deal and they way it loops it kind of looks like it's supposed to be there so no big deal. I could get a new line but on these bikes the line turns to steel brake line as it goes under the gas tank and into the abs pump. To swap it I could do some custom lines(I'm not doing that), order a line from and SP, buy a line kit and bypass the abs completely. It could drop like 15-20lbs off the bike by removing the whole system (i ride in all weather and like the option to just commute without paying attention in the rain/snow so it's not likely I remove) or just leave it like it is now(most likely what I will be doing).

Before this whole project started I ordered some matching rizoma reservoirs. The guy included fancy aftermarket rizoma mounts as well... But... They were different from one another and one was a design I couldn't utilize due to my whole configuration so they went into the parts box and I made some simple matching rubber mount aluminum mounts. I'm happy with them.

I am very happy with the outcome (except for a little annoyed about the right switch assembly). It looks so clean and open with less clutter. It's 30°f right now so I only went around the block and too the park to take pics but it feels good.

For those that are focused on weighing evrything(I weigh everything just to see the difference, not to focus on dropping every oz) the old bars were steel. The protaper are aluminum. The OEM bolts, bars and clamp weigh 1394g(3.07lbs). The protaper bolts, risers and bars weigh 1146g(2.52lbs). I will nolonger be running the carbon fiber hand guards for now. If I were to want to put them back on I would need to machine the inner mount to fit the fat bar taper or switch to a fat bar bark buster clamp.

Now I need to make some new bar ends with delrin sliders. The inside diameter on the protaper is very small and I might make some sort of thread in bar end slider as opposed to a wedge style like I have made in the past.
 

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Other than looking cool especially in all black and beefier tubing....what is the advantage of these over stock?
 
They feel stiffer while riding around, they vibrate less and my hands no longer go numb (I'm guessing due to the different bend and hand placement). I didn't know that was going to happen. I went into the swap purely for cosmetic but these little changes are a very happy surprise.
 
I pretty much did the same thing. I went with the Pro taper Ricky Carmichael bend. Which was the perfect bend, sweep etc. You lose a lot of weight over the heavy steel oem bars. I also ditched the useless plastic hand guards that attach with super heavy pins inside the bars. I cant believe how light my steering became.
 
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