51mm JGR/Showa A-kit Forks | Unobtainable Parts Obtained!!!

I have never heard about 51mm forks. That's quite interesting! Congrats on the new bike BTW!

Those have to be the rarest of the rare right there. I have always been of the opinion that the larger air chambers allow for a more progressive stroke and bottoming and that the less flex actually make them smoother since there is less stiction from flex binding. It will be interesting to hear how you like them. Amazing that you bought this bike (how much?) and did you know they were on there? Obviously the trickest works part on the machine. Way cool stuff bro!

Ask ML512 about them, as he should be able to give some good info concerning them, or at least find out for you.

Those were not meant to be available to the public and you will have a hard time finding parts for them. I would contact JGR and buy up as many spare seals and bushings as you can get. I know someone with a set from Dungey's last outdoor RM and he was able to get a few sets from RG3 but those were supposed to be the last parts they had from when they worked with Suzuki on the factory teams.

WOW!!! Thanks guys for all the response!! I was honestly speechless when I saw the bike on craigslist, I knew the forks were at least showa a kit but I had no idea how serious they actually were!! The bike also has a custom JGR/JRI rear shock on the bike, a full race gas only JGR engine, hand made Ti footpads, and is littered with Ti bolts. The more I look at this bike the more trick stuff I keep finding! The previous owner had NO IDEA what they had.....

slipdog wrote:

Those were not meant to be available to the public and you will have a hard time finding parts for them. I would contact JGR and buy up as many spare seals and bushings as you can get. I know someone with a set from Dungey's last outdoor RM and he was able to get a few sets from RG3 but those were supposed to be the last parts they had from when they worked with Suzuki on the factory teams.

Thanks Slip, I was afraid that might be the problem with having something so rare... I figured I was going to have to search for seals and bushings, so calling JGR is now high on the list of priorities!

More pics of bike and trick stuff on

Congrats dude, you've found a "treasure"! Could you post more detailed pics of the whole bike?

And may i ask how much you payed for the bike since the previous owner didn't understand what he had?

In for more info and pics.

Man, I'm jealous
Nice find! Give us more pics!

Haha thanks guys!! I'll post more photos tonight once I get off work! I'm super stoked to have this, it's always been a dream of mine to own a factory bike but I never thought I would achieve that dream so soon (I'm only 18 years old and have the dirtbike addiction pretty bad!!).

I plan on pulling the bike apart and finding out what is really inside and will be posting more photos and explaining my findings along the way!! I actually started this morning about 3 minutes before I left for work, I pulled the clutch cover off to find a full Hinson clutch assembly!! I can't wait to dig into it more!!

You know you'll never be able to corner on that bike!
Also the suspension is too stiff for you!

Awesome find. Forks must look big

Jrewing wrote:

You know you'll never be able to corner on that bike!
Also the suspension is too stiff for you!

Awesome find. Forks must look big

Oh come on give me a chance!! You don't know what kind of rider I am Haha!!

And just so everyone knows, one of my jobs is I am a tech at a local suspension shop. So if I wanted to I could have custom springs made and valve it for my weight and ability quite easily, the big problem will be finding seals and bushings unfortunately.

I found my first markings on the bike!! On both the fork lugs they are inscribed with 12-51-03R and 12-51-03L (R for right lug and L for left lug presumably). I'm assuming because the bike is a 2012 that's where the 12 comes from. And 51 for 51mm lower tube diameter. The only one that is up for debate is the 03, does that mean that this is the third set that they made? I am planning on contacting JGR soon to try and get some more information.

Another cool thing I found out when I took the front wheel off is that they used this one piece titanium spacer/collar/axle nut in the left lug to allow them to use a stock steel axle in it even with these big beefy cleats!!

Gnar! Let us know how they ride!

CarlinoJoeVideo wrote:

Gnar! Let us know how they ride!

I definitely will let everyone know!! I plan on riding the bike for the first time tomorrow, so I should have a ride report soon!

FRANZINI499 wrote:

Another cool thing I found out when I took the front wheel off is that they used this one piece titanium spacer/collar/axle nut in the left lug to allow them to use a stock steel axle in it even with these big beefy cleats!!

Wow what a "barn" find. I bet you are right about 3rd set made, obviously hand made billet. It's great that you are comfortable with suspension, I'm curious to see the internals. Jealous, what a find.

I may be wayyyyy off, but any chance they are, at least partially, KYB stuff???

nch209 wrote:

I may be wayyyyy off, but any chance they are, at least partially, KYB stuff???

No sir! I'm positive they are showas, there are many ways to tell but the easiest way to tell is the top base valve caps.


Stock KYB AOS ^

51mm Showa^

Are they aluminum or steel stanchions?

nytsmaC wrote:

Are they aluminum or steel stanchions?

The lower tubes are steel with what I believe is a blue ti nitride coating

Alright so I had my first ride on the bike on Saturday out in Club Moto in Livermore, CA in the miserable 102 Degree heat, but that was not what my head was focused on that day... It was focused on how this bike rode with this very special suspension on it! My first couple of motos were a little hectic due to the track being very crowded and me not being used to the power of this beast! After I started to get a bit more comfortable I was able to really think and feel how the suspension was working... I didn't even touch the clickers or any of the settings for the first few motos just to get a baseline, and just wow!

It was unbelievable... I am a suspension guy which I stated earlier in the thread and I have never ridden anything quite like this stuff!! It was pretty stiff at low speeds and through bumps in the parking lot, but once I learned just to let it plow through the chop and all the nastiness on the track it really started to shine. There was no harshness, the stroke was buttery smooth and seemed like it was impossible to bottom. I even took crappy lines and over jumped some stuff on purpose just to see what it would do and it just seemed to keep wanting more!!

I can't wait to really go out and try this stuff on different tracks (maybe even hit some trails with it) and try to learn more about how it acts and test how versatile this setup can be made. I have started to talk to JGR's race team suspension tech Jonny Oler and am trying to learn about the history of these components and hopefully try to track down some parts, because I plan on using these things like they were designed to do!! Or maybe just a bit slower than they were designed to actually... Haha!!

What if you're running James old forks? Kinda cool

HenryA wrote:

What if you're running James old forks? Kinda cool

What if I'm running James' old bike! I'm not sure yet, but hopefully I'll get some information soon!

JGR is one of the teams that i know has auctioned off bikes at the end of the year. I've seen some of their old practice bikes floating around the internet. James was also notorious for testing a bunch of different suspension setups and changing mid season, though showa is pretty consistent with what he and davi millsaps ran in their JGR days. I am very curious as well to see what you dig up. Have you search the frame at all, i know a lot of teams will mark cartain frames with ridiers names or initials.

HenryA wrote:

What if you're running James old forks? Kinda cool

FRANZINI499 wrote:

What if I'm running James' old bike! I'm not sure yet, but hopefully I'll get some information soon!

I think it was last year out at PCMX there was a guy who had a JGRMX team bike..... The owner that that time stated it was a beast of a bike, this bike also had full race motor and factory one off suspension.... same bike??

NJKawi913 wrote:

JGR is one of the teams that i know has auctioned off bikes at the end of the year. I've seen some of their old practice bikes floating around the internet. James was also notorious for testing a bunch of different suspension setups and changing mid season, though showa is pretty consistent with what he and davi millsaps ran in their JGR days. I am very curious as well to see what you dig up. Have you search the frame at all, i know a lot of teams will mark cartain frames with ridiers names or initials.

I haven't had much time to take the bike apart too far yet, so I have not found any markings on the frame or the rest of the bike. I will hopefully be getting some time to dig into it soon and see what I uncover!

Seals should not be to difficult. All you have to do is got the old seals and take them to a bearing or seal shop. They can match the numbers and get some seals. Also the springs might not be to bad it could possibly use 49mm springs. The kyb 50mm stuff just uses 48mm along with the 52mm cone valves use 48mm springs. Let's see some pics of this bike!!