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forks and valves... WTF?
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Discussion Starter · #1 ·
After a great build last year with the RD400 http://www.customfighters.com/forums/showthread.php?t=61719, I was planning to sit out of this year's Dirtbag Challenge https://www.facebook.com/photo.php?v=445717822038. I've been designing my 2014 build (based on a Ducati 750 Monster) and have been pretty focused on that... then this happened...



I found this 450cc KDX advertised on Craigslist for $250. Actually paid $200 after finding out there are some back reg fees due. The bike had been sitting since around '07. Once I had it home I took the carb apart to make sure it was clean inside (it was), and put fresh gas in the tank... then two kicks and it fired up! It runs pretty good for an '82.

Because I don't want to mess around with DMV trying to get street reg for a dirt-bike, a friend gave me a titled (current with no back fees due!) GS550 frame, so thats what the bike will eventually be titled as.

The plan for Dirtbag is to scratch-build a custom frame around the 450 engine and just enough bits off the GS550 frame. I have a spare set of R1 wheels and forks, and a R6 tank and seat. The look I'm hoping for is kinda modern raked-out hardtail chopper contraption with the expansion chamber routed up over the the big rear tire.

I'll try to put up a few more pictures of the accumulated parts in a few days. Of course as you've seen with some of my other builds, I'll eventually have some sketches to show as I go. Then hopefully a few build photos later on, but with only 30 days allowed for the build-off the time gets very hectic, so we'll see how that goes when the time comes.

so stay tuned for more 2-stroke madness...
 

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I've really enjoyed your past builds, but I'm wondering why you're doing another raked out chopper this time, is it personal preference or is that what they're looking for at the bike show? I'd like to see you tackle something different.

Either way I'll be following it closely :rock:
 

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This looks interesting
 

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fighter transplant in NC
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yeah, I was kindof hoping to see something a bit more streetbike oriented. regardless, I always like your builds. so I'll be happy to see what you come up with
 

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forks and valves... WTF?
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671 Posts
Discussion Starter · #5 ·
I've really enjoyed your past builds, but I'm wondering why you're doing another raked out chopper this time, is it personal preference or is that what they're looking for at the bike show? I'd like to see you tackle something different.

Either way I'll be following it closely :rock:
That's a really good question... For as long as I can remember I've loved road racing bikes and spent most of my adult life building roadracers. I even started a business back in 2000 building frame kits for local club racing. Here is what the kit bikes looked like...






Then I've had this ongoing project for the last 20-something years...



There have been many other projects, but it all kinda started with this little concept I built for a college class...


So I've had plenty of experience with other types of bikes. The Dirtbag Challenge is billed as a "chopper" build-off, although most all types of bikes are welcomed. When I did my first Dirtbag build in 2010 I decided to combine my love for sport bikes with the chopper theme. I started with a 700 Interceptor that was raked, lowered, and stretched to 8 feet long. I discovered two things in the process... first, it was totally fun to build. I wasn't concerned with building a bike that had to win races or prove some engineering theory as with most of my previous projects. Second, it was actually very fun to ride and didn't handle as bad as I expected.




So anyway, I like all (or most) types of bikes and building these Dirtbag choppers as been a lot of fun. I do have some other projects in the works including a custom framed (modern road race style) RZ500
and eventually I'm planning to build a batch of custom RZ350 frames with modern race geometry. But for now, I'm taking a mental vacation with these Dirtbag chops.

Thanks for the question, and I appreciate the props!

cheers,
Julian
 

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forks and valves... WTF?
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671 Posts
Discussion Starter · #6 ·
A little later today I'm going to post the first CAD images and sketches... but first I wanted to make a comment about DMV registration. Friday I went to DMV to transfer title on the KDX and GS550 frame.

The previous owner of the KDX never transferred title into his name and thus never even considered that he needed file for non-opp status if the bike was not going to be used. I got dinged with back reg fees in addition to the normal transfer fees, although the clerk did wave the penalty portion. New title and sticker set me back around $150.:angry:

The GS550 was currently titled to the person I got it from and had been issued an up to date non-opp status. My cost for the transfer was only $24.:party-smiley:

So I just need to rant a little about how it pisses me off that people can't keep their paperwork in order. One thing that did help a bit is DMV now has an on-line fee calculator so you can get an estimate of fees before you make a vehicle purchase. I was able to use this info to negotiate a better price on the KDX so it kinda evened out and the seller took some of the cost burden. But even so, he could have saved both of us some money by filing one simple form to prevent the back reg fees from accumulating :doh:

And as a side note, there is an understanding (at least here in CA) that any vehicle in DMV system that has been unregistered for 4 years goes out of their system... I believe this is no longer true. The KDX registration had expired in 2007 (6 years back) and it was definitely still in the system.


Anyway, stay tuned for pictures coming soon...
 

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forks and valves... WTF?
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671 Posts
Discussion Starter · #7 ·
As promised, here are a few early CAD images. These are just a rough start and will be fine tuned in the next few days including adding bracing tubes and adjusting the seat support angle and position... but you should get the general idea of what I'm going for with this build.

Before everyone starts in with comments about why don't I do this or do that... like adding rear suspension... keep in mind that when the hammer drops and "go" date is announced, this will need to be built and ridable in 30 days!







 

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forks and valves... WTF?
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671 Posts
Discussion Starter · #9 ·
Here are a few sketches. Most of theses are just focused on some of the frame details such as the end plates and various ideas for bracing between the main tubes. In the bottom sketch I realize that the engine is way out of proportion and located too high in the frame... but it's just to get the initial idea on paper.







 

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That is going to be stuff ride but it looks pretty damn good.


Not to get off topic or anything but those custom frames you built. What motor is in there? Are those gsxrs? They look really fucking good and Im very curious now.
 

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forks and valves... WTF?
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671 Posts
Discussion Starter · #13 ·
That is going to be stuff ride but it looks pretty damn good.


Not to get off topic or anything but those custom frames you built. What motor is in there? Are those gsxrs? They look really fucking good and Im very curious now.
Nope, but glad you like the race bikes!

looks like ninja ex250. pretty neat compared to stock
very close, but...

Iirc they were his ex500 race bikes. True sexyness
winner! Yes, the engines are Kawasaki EX500s.

The two red race bikes were 2nd and 3rd overall AFM 500cc Twins in 2001. And one bike was 2002 AFM 500cc Twins Champion. Also numerous AHRMA 2nds and 3rds in 2001 racing against SV650s.
 

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forks and valves... WTF?
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671 Posts
Discussion Starter · #14 ·
Here are some of the accumulated parts that will be going into the build. Starting with a GS550 frame that was donated by a good friend. Of course the frame will get some extreme modifications... but that's what the bike will be titled as :Evil_smile:



R1 forks and wheels...



yep, that's a 190 tire on the rear :D



not sure if I'll need these, but have some R1 (or R6, I forget) rearsets ready just in case they are needed...

 

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forks and valves... WTF?
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671 Posts
Discussion Starter · #15 ·
It was bugging me that the sketch I posted yesterday wasn't very accurate... so I did a new sketch last night with the engine more correctly proportioned and located in more accurate position. I was drawing on the train while going home from work so its kinda scribbly since the train isn't very smooth. Anyway, should be a little better....

 

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forks and valves... WTF?
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671 Posts
Discussion Starter · #16 ·
For those who don't know, a Dirtbag documentary has been in the works for several years now. It looks like its finally going to be released next month. Here is trailer #2 (you can google search for trailer #1)

enjoy :party-smiley:

https://www.facebook.com/photo.php?v=10151800766257039

...and if you got the balls, build a bike and come to the event:shocker:
 
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forks and valves... WTF?
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671 Posts
Discussion Starter · #18 ·
Everyone is still waiting for the "go" date to be announced for the Dirtbag Challenge, but I thought I'd post a few small updates...

First, I was able to take the KDX450 out for a trail ride over the weekend. After riding the same trails first on the KDX, then again on my YZ250, I am even more convinced that putting the KDX engine into a street bike is the correct thing to do. In the dirt it makes tons of power and all of it is low to mid-range toque. It wants to put like a tractor. The rest of the bike is horrible... the suspension is bad and in big whups the rear end wants to come around. And brakes... well, what brakes? Going down hill I could stand on the rear pedal and the bike would barely go slower. Anyway, I came away feeling very confident that taking this bike away from seeing anymore dirt in its life time will be a good thing.

Second, I've been having doubts about using the Suzuki GS frame since no other parts on the bike will be from a Suzuki. Doing a search on Craigslist I found a 1970 Yamaha R5 350 frame for $50. So I bought it. Using a spare RD350 set of engine case and a bunch of spare RD400 parts I built up the frame just enough to get it through the CHP inspection process. I now have the CHP report and all my DMV papers ready to make a final appointment at DMV. The frame has been out of the DMV system for over 30 years, so not sure how it will play out with the fees. I could be back to the GS frame if the fees get too crazy with the R5. Stay tuned....

An lastly, it wouldn't be a good update without some pictures, so here are some recent CAD updates with headlight, exhaust silencer, and more frame tubes added. I'm not crazy about the headlight, but its what I have for now. Basic chrome bullet style. I'd like to get a black Victory headlight if anyone has a lead on one(?)







this is the headlight I'd like to find...



in black like this...
 

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Very fucking cool if you don't have a use for the r1 rear sets I maybe interested in taking them off your hands. PM me if you decide to get rid of them I won't remember to check this thread for them lol
 

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#114 CVMA/STTARS
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Everyone is still waiting for the "go" date to be announced for the Dirtbag Challenge, but I thought I'd post a few small updates...

First, I was able to take the KDX450 out for a trail ride over the weekend. After riding the same trails first on the KDX, then again on my YZ250, I am even more convinced that putting the KDX engine into a street bike is the correct thing to do. In the dirt it makes tons of power and all of it is low to mid-range toque. It wants to put like a tractor. The rest of the bike is horrible... the suspension is bad and in big whups the rear end wants to come around. And brakes... well, what brakes? Going down hill I could stand on the rear pedal and the bike would barely go slower. Anyway, I came away feeling very confident that taking this bike away from seeing anymore dirt in its life time will be a good thing.

Second, I've been having doubts about using the Suzuki GS frame since no other parts on the bike will be from a Suzuki. Doing a search on Craigslist I found a 1970 Yamaha R5 350 frame for $50. So I bought it. Using a spare RD350 set of engine case and a bunch of spare RD400 parts I built up the frame just enough to get it through the CHP inspection process. I now have the CHP report and all my DMV papers ready to make a final appointment at DMV. The frame has been out of the DMV system for over 30 years, so not sure how it will play out with the fees. I could be back to the GS frame if the fees get too crazy with the R5. Stay tuned....

An lastly, it wouldn't be a good update without some pictures, so here are some recent CAD updates with headlight, exhaust silencer, and more frame tubes added. I'm not crazy about the headlight, but its what I have for now. Basic chrome bullet style. I'd like to get a black Victory headlight if anyone has a lead on one(?)

this is the headlight I'd like to find...



in black like this...

Like this one?





Ebay link. $45

http://www.ebay.com/itm/Motorcycle-...tory|Model:Hammer&hash=item2581d219b3&vxp=mtr
 
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