View Full Version : My CR500 conversion "Official Thread" 4/10/08 updated.

Louis Mielke
04-17-2007, 06:38 PM
Well I've had numerous threads on this thing and I still have my website, www.atc500r.com, but I'm busy waiting for parts to finish putting the thing back together for trikefest so I've decided to work on an official thread to try and consolidate everything. This conversion has been going on for several years now, and as everyone knows this kinda thing is never done. I've also had a lot of setbacks and lessons learned the hard way so a lot of this info is old news.

Current Progress Pic as of 4/17/2007

So, here's the bumpy story on my conversion.

The money pit....err..saga begins!!

Well it all started back when I was a freshman in college. I had a few different dirt bikes and atvs, I loved to ride. I had just gotten hooked on three wheelers and had started paying attention to anything in the magazines I could find about them.

It just so happened I had bought an issue of dirtwheels that had an article on an awesome CR500 trike conversion a guy named Tony Wyatt had done. This guys bike got a whole two pages in the mag and a good bit of it was interview, it was freakin awsome! Right then and there I knew I was going to build one.

Tony's bike was so sweet! He had leagers build him a new (this was year 2000) CR500 trike swinger just like from the 80s and had custom subframe and triples made. His 500 used various 400ex part and turned out totally sweet. Wish I could find that magazine.

So that was my inspiration and irrational spending was to follow. Obviously I didn't want an exact copy of Tony's bike, how un-cool would that be? So I set a few goals.

The main goal was to build a Honda ATC500R. Obviously since this is a bike conversion many trike enthusiasts consider this a ATCR500R but labels matter not to me.

My original intentions have changed somewhat since my website days so some of that has gone out the window. One of my biggest goals was to use as many available off the shelf parts as possible for the sake of maintenance and parts availability.

Next goal was for this bike to look as factory as possible, very professional and high quality. I think I’ve met that goal somewhat.

Another goal has always been that this was to be an all purpose trike. I’m not really a drag racer and I ride all kinds of terrain so this bike was meant to handle them all. Once again I think so far so good on that goal. Lol

Well with some general goals set its on to the beginning of this lofty project. My build started off as a bare 1987 Honda CR500R frame purchased from eBay. Along with the frame came the stock triples and forks all for $100, score! Around that same time I had spotted an ATC250R front wheel, hub, and triple clamp also on eBay and snatched them up as soon as I could.

Already you can see the general idea forming. The last major decision was the rear swing arm. The leagers arm was rumoured to cost upwards of $500 and at the time I was a poor college boy, that was not an option. I toyed with the idea of cutting down a 250R swing arm to fit the CR500 frame but being that the arm was steal, it looked like it would be too much work, with very poor results. Finally after strolling through the local ATV dealership I came upon the perfect swing arm, the 400ex rear swing arm! This swinger was cast aluminium with a proven rear axle and break set-up. After taking some measurements and eye balling some options the decision was made and I set my heart on combining a 400ex ATV swing arm with a stock CR500R arm.

Anyway from here on the thread will be broken up into chronological sections of how the build progressed until I get to current date.

Louis Mielke
04-17-2007, 07:13 PM
Front End…er.. Wait, would an end be at the front?

As stated earlier my first two purchases for the project were a 1987 CR500 frame complete with triples and forks, plus the triple clamps, front wheel and axel from an 1986 ATC250R. So having these parts and obviously not wanting to wait to get to work I set out to adapt the wider ATC triples onto the CR frame. I was very concerned at first because I was not sure how the ATC clamps would fit the CR frame. There is a large difference in the head tube and stem lengths between the trike and dirt bike. Luckily for me Honda went with a two piece triple design on both machines and the stems can be removed from the lower triple plate. Off to the local machine shop I went to have the stems pressed out of both clamps with a hydraulic press. Once again I was concerned that I may have hit a dead end. If the stems where drastically different in diameter at the lower end pressing would be futile and my quest for an ATC500R would hit a brick wall that would require machining. Low and behold the two stems where the same lower diameter and the CR stem pressed right into the ATC250R clamps! Now I had ATC triple clamps that could bolt to my CR frame. It was quite a relief and at this point I had actually begun to feel that this project was really going to happen.


The next hurdle was not nearly as climatic but still interesting none the less. The forks on CR500 are mammoth. I'm talking super beefy. These forks really impressed me but presented me another impasse. The stock ATC forks are much smaller in diameter that the CR500 forks. Either the forks would have to shrink, or the clamps would need to grow. Well off to another machine shop I went, luckily this shop, “Greenmount Precision Machining”, (shameless plug) just happened to be owned by a good friend of mine, Cart Denner. He is a master welder and machinist and he has been invaluable in my pursuit of this project. Well after some deliberation with Mr. Cart, he decided that there was enough material on the ATC triples that he could EDM wire cut the holes larger to accept the CR forks. This left some concern about strength of the clamps but we proceeded with high hopes.


If you look closely at my frame you will also notice that we fabricated a block for the ATC clamps to stop on at the end of the pivots rotation. This block was measured careful through repeated test fitting with the radiators mounted on the bike.


Another note that may interest some, the stock ATC250r front axle will not fit into the CR forks without some modification. My axle had a shim machined for the outside of one end of the axle and one of the CR forks had to be rethreaded to accept the threaded end of the axle.


At this point I had a bit of a decision to make, if you take a look at the below pictures, you can see that one has the axel in front of the fork like a Honda ATC350X and then one has the axel behind the forks like the other Honda ATCs. This location of the front axle greatly affects the “rake” of the front end, or simply stated, how stretched out the front end seems. This “rake” along with the “trail” of the front end on any bike changes the steering and turning characteristics of the machine. At first I was undecided on how to run the axle. The axel behind the forks sets the rake at a more appropriate angle but the axel in front places the brake caliper in the correct location. After test riding some other bikes with some axle changes made I finally decided that rake and trail were more important than brake placement, and that for my particular application the axle behind the forks position would work out better. Trailing axle it is!


Louis Mielke
04-17-2007, 07:58 PM
A CR500 engine

Well obviously I needed an engine so I started poking around the net, I specifically was looking for one of the 80’s engines because as far as I had read the older ones were more powerful as the later models had been detuned to mellow the power band. EBay engines were going for way more that what I really wanted to pay for an engine that I was only vaguely sure about the internals. I bought my engine as a package from the “Bike Bone Yard” (http://www.bikeboneyard.com/). I paid $500 for the engine, electrics, radiators, carb, and bunch of other miscellaneous stuff shipped. Honestly in retrospect I could have done better on eBay but I was impatient. I tore down the engine and had to do quite a few things to it. The top end was bored and honed with a new weisco piston on it's last bore, new main bearings, OEM rod & rod bearings. (weisco doesn't make a hotrod kit for this year engine) I also went ahead and replaced the clutch steels, fibers, and springs, water pump shaft and complete kick start gear & spring assembly. I also replaced the intake boot with a newer style one. The 90s intake will bolt right into the old 80s cylinders. A few months later I decided to go ahead and replaced the entire right hand outer crank case cover along with replacing the ignition cover with the BLING BLING cover from Service Honda.


Yet another couple months later I decided to have a decompression system installed in my cylinder. That was done by Accu-products to the tune of $200.


As far as other engine related components are involved some other small titbits. This cylinder is on its last bore, at 91mm, I do believe that brings this bike in at 514cc. I'm no math wiz, or an engine builder so I'm probably wrong. Feel free to correct me.

I sold the old carb that came in my engine package and purchased a brand new PWK 39mm carb. Running 55 pilot as of now, and a 172 main. I suck at jetting so I bet this is also off. Hopefully I'll get it dialed in sometime.

The cylinder head has been re-cut and surfaced by our very own, "Hey Ron, Git It Rag Racing!" Ronnie does awesome work!

I'm currently running a FMF gnarly pipe on this bike. Many have said I'd get better top end from a Pro Circuit. I may end up with one yet. Time will tell.

Ok so now that I've told you about my $1K engine...lol. More is planned for this engine but that will be discussed at the end of my thread. Oh and class please save your comments untill after the discussion. lol

Louis Mielke
04-17-2007, 08:30 PM

Well here’s the big deal in my honest opinion. I’m sure there are lots of opinions on this piece and that’s cool. Maybe this wasn’t the best way, and maybe it won’t hold up in the long run but so far its been great and taken a beating. The swing arm for my 500 is a Frankenstein’s baby. Between myself and my machinist friend, Cart, we grafted the front half of the stock CR500 swinger, to the rear half of a 400ex swinger. This allowed me to use all of the readily available rear-end parts from a 400ex, and have the plush pro-link suspension from the CR500. I was basically the creative genius and grunt worker while Mr. Cart did the painstaking tig welding on this bad boy. After everything was whole again I took it to the polishers to have it prettied up. The pictures really speak for themselves here. In retrospect I wish I would have used the 450r swing arm but at the time we were working on the swinger the 450r really hadn’t been around long enough to warrant using those parts.







With my linkage set-up and the stock CR frame, a stock CR shock made sense...well...I threw sense into the wind and called Works Performance and had them build me a shock. It turned out nice and rides like butta!


Sadly I failed to address the largest hurdle well. chain alignment is a big issue with this kinda of conversion. I thought I have measured carefully. Unfortunately i hadn't. My sprockets did not line up properly. To compensate we had to cut a billet spacer to address the chain alignment. A lesson learned the hard way sadly.


Other than the alignment issue that was overcome the swingarm build went well.

Louis Mielke
04-17-2007, 08:37 PM

Building a 500, whether using a trike frame or the CR frame presents a major problem that most are aware of, the kick starter swings towards the rear, instead of towards the front like factory atcs. Revising the kick direction is not very practical because as anyone who has ridden a CR500R knows kicking these monsters can be a pain. You can't really kick start the beast as much as you kinda jump start it. The required force would put a great amount of stress on any kinda of external reversing mechanism and would more than likely break the shafts and gears. To get around this problem others who have done this conversion before me have done various things. Some have cut the fenders producing a racy look and allowing the rear kick to clear the fenders no problem. Others have built simple rear fender pivots to "flip" the seat & fenders backwards moving them out of the way. My 500r has gone through some design changes in regard to the subframe to address the rear kicking dilema. At first I had planned a somewhat complicated subframe which would "slide" the rear fenders out of the way of the kicker path. After many mock ups and test frames that idea was scrapped. It was just too hokey. Now my bike is using a Yamaha blaster kick starter to clear the fenders. The blaster kicker is short to start with and with the decompress system installed I've actually shortened it another inch. This short kicker allows my fenders to be mounted in a stock fashion without getting in the way of the starter.

Another issue with my subframe comes from the exhaust, in order for the silencer to mount on the subframe properly I was forced to notch the rear portion of the expansion chamber in order to redirect it to the right by an inch. So far I don't believe this has been detrimental to the engines performance and the welding came out clean and hardly noticeable.


Louis Mielke
04-17-2007, 10:06 PM

I really didn't want to run this beast without an air box as a lot of people do. That severely limits where and when you can ride a bike. The air box keeps mud and water from getting to the air filter and I ride a wide variety of terrain making an air box a must. My good friend Joey is an excellent air-conditioning duct work fabricator and with his and Mr. Cart's help I set out to fabricate an air box. We first started with a rough design and then fashioned a prototype from galvanized sheet metal. After we were satisfied with the design, Joey went to work on some light weight aluminium sheets and Cart welded everything together. While I am running an air box, it is in design open air, meaning it has no lid. The seat is mounted directly over the box and acts as a cover well enough to keep large debris from entering. I may run a prefilter eventually when extra fundage permits. This thing turned out very nice and I have to give mad props to Joey and Cart!





Louis Mielke
04-17-2007, 10:21 PM

My original vision of this bike was based largely on the pics I saw of Tony Wyatt's bike in dirt wheels. This being said its understandable that my first choice for plastics would be similar to his. The front fender was easy enough as I love the look of the stock 250r trike fender. For rear fenders I had chosen to emulate Tony, and use the 400ex fenders and seat. The fuel tank unfortunately was a very limiting factor. I first ran a 4 gallon large capacity tank from Clarke which worked fine and dandy.

The fender choice unfortunately did not cooperate with me when it came to seat design. I had originally spent extensive time with a heat gun to reshape the stock 400ex seat to try and match the tank well. Needless to say the whole debacle went badly and it was back to the drawing board.

Here's a pic of the abortion I speak of.


Well back to the drawing board, but it was a good thing! I soon discovered that a 450r seat was lower in profile and narrower at the nose and would suite my purposes very well. So I bought said seat, and well obviously neccesity had me sell the 400ex plastic and purchase 450r rear fenders. From there some minor mods to my subframe and I had a pretty sweet looking rear fender/seat setup. The seat still didn't match the tank perfectly but it didn't look too bad.


It took some tweaking and some minor heat gun work but it didn't look half bad when I finally took it to TF06.

Louis Mielke
04-17-2007, 10:30 PM

Foot pegs! Gota have some place for my feet right? Well I think these were the easiest thing to put together during the first build of this bike. I took the stock CR pegs and cut the outer "skin" off of them until l was able to make the pegs fit inside of some dissected 400ex foot pegs. In this way I not only extended my pegs but created a much larger space for my foot. A little powder coating and I considered these functional. I do like these pegs , but I had chance to see some IMS pegs Hagen had modified for Billy at Trikefest and I must say a pair of those maybe in this bikes future. Actually the future is definitely bring a foot peg change for the third build but more on that later.


Louis Mielke
04-17-2007, 10:52 PM
Wrapping up the first build...

Well up to this point this has all been info about the initial build of my 500. Trikefest 2006 was quickly approaching at this point and I started scrambling to tie up the loose ends so this bike could make it to Indiana.

I buttoned up my controls. All fairly common stuff, 400ex throttle, standard hydraulic front and rear brakes, 450r hot start lever for my decompress. All fairly standard stuff.



All in all my 500 didn't look too bad for TF. The largest issue was the ride height. Ride height is pretty much the main plight of all dirt bike to trike conversions. Its just hard to make a bike frame sit and handle like an ATV. Mind you the 500 was not un-rideable. I had no trouble getting the thing around the MX track or through the woods trails and of course it was fine on the drag stip, it just took more muscle, and more body english than a factory ATC. I attribute most of this to ride height and some really crappy rear tires which I've worked hard on alleviating during the second build. More on that later. Here's some comparison pics. Notice the 500 is not that much taller than a stock 250r but its enough to make a major difference. (Thanks to my room mate and friend for weighting the suspension while I took pics)



I did have one other detrimental set back, a blown head gasket. For TF06 my 500 was crippled badly for the fact that I was stupid (or should I say out of time) and tried to reuse the head gasket after having to remove my top end last minute. This was costly as I did in fact over heat my cylinder which required me to replace the rings during the second build. It is to be noted that I had Ronnie machine the head for the second build, it had not been done for the first.


That pretty much concludes part one of this thread. I'll be continuing part 2, the rebuild tomorrow night. You can commence your jests, comments and snod remarks now if you like. lol

Thanks for tuning in and tune back in same bat time, same bat channel.

04-17-2007, 11:07 PM
yep... im going that rought I need to build me a 500 you just added to much fuel to the fire.

04-17-2007, 11:29 PM
Very nice man. Looks like all the work has paid off. One Bad *Edited**Edited**Edited**Edited**Edited* machine

Louis Mielke
04-17-2007, 11:36 PM
Its a labor of love still in progress. More on it tomarrow night but I plan on buying a second CR frame and modifiying it pretty heavily.

04-19-2007, 02:32 AM
here's some pics of my cr500 nasty project. i bought the 87 cr500 just for the engine, and after searching around for engine swap ideas, i came across some of your pics and info. well, i just rolled mine out of the garage today as a rolling chassis. i am going to bring it to work tommorow so the guys can me a few last minute ideas, then she's coming apart to finish welding the swing arm and to re-paint and polish the bike. i still havnt decided how to do the subrame yet. i have a rear fender and seat from the 250r donor bike, we'll see. anyways thanks for the inspiration (all my rear end components are trx 450r pars, they are so cheap on e-bay right now) as for now i have about $300 in rear end parts, $250 for a 250r minus the engine, and i bought the cr500 for $ 350 (which the guy just paid 800 dollars to have rebuilt and rode it once). i'm doing all the work and fabrication myself, so as of now i have 900 - 1000 dollars in it, and it should definatley be worth that on the first ride just from the smile its gonna put on my face, lol.


04-23-2007, 12:25 PM
Louie, Louie, Louie... I'm lickin my chops here waiting on some more write ups! :D

Louis Mielke
04-23-2007, 03:51 PM
Chris I hope to get some more time to write tonight, as of right now though i'm trying to finish the roof on my shed before these storms they're calling for show up.

Trust me though you'll get to see it up close and personal soon. I hope to come take it for a good day of test riding up in hazelton maybe even this weekend. We'll see.

04-23-2007, 09:29 PM
look awesome i would love to have one it must fly

Louis Mielke
01-25-2008, 12:18 AM
Well, its under the knife again. The shorter swinger has been finished and installed along with a +4 lonestar axle. Also installed shorter handle bars.

This picture was the latest one I had available to me at the moment so i photoshoped it to represent the change in the subframe and seat height. No its not a picture with the work done but its very close ot what it looks like. I'll get updated pics as soon as I can but this is what it looks like right now.


Next is getting the topend redone again, the lowboy exhaust and respringing the front end with new seals.

03-13-2008, 11:07 PM
To the top.

Louis Mielke
04-10-2008, 11:37 PM
Recent pics. -2 subframe, lowboy pipe, -4 off swinger, +4 rear axle. More work to be done. A minor ride report = a million times better.

Gota make exhaust mounts. blah.


92 exhaust on an 87 frame. Tight fit but doable. Need to make custom silencer pipe.

Billy Golightly
04-11-2008, 12:51 AM
Awesome, looks real good Louis. Glad the swingarm change was in the right direction, looks like it still holding up good too :) Did your chain guide up there fit on without much problem? I remember that was kind of a problematic area for me when I was working on welding it all together.

04-28-2008, 04:18 PM

Looks great - what foot brake pedal did you use? It that like a CR500 pedal or what?

04-28-2008, 04:55 PM
One of my favourite trikes. Dig the new look.

04-28-2008, 09:18 PM
The new pictures look awesome man. Great work.

04-28-2008, 09:28 PM
Sick trike man, nice work.

Louis Mielke
04-28-2008, 09:43 PM

Looks great - what foot brake pedal did you use? It that like a CR500 pedal or what?

That is the CR pedal Tim but it needs a little modification to work perfect. The bulk of the changes are done I just need to get some of the details worked out for TF.

Thanks for all the positive comments guys. It keeps a guy motivated.

04-29-2008, 12:32 PM
Million times better buddy, No question

Can i ride it???? hahaha

01-30-2009, 03:11 AM
I know this is an old thread, but I just creamed my shorts, thought you ought to know lou

Louis Mielke
01-30-2009, 08:04 AM
Old thread, old version of the bike. Here's the newer version. I'll get around to adding to the thread eventually. Thanks though! The new one is a million times better!


The big 3
02-01-2009, 06:52 AM
looks wicked

02-01-2009, 02:28 PM
Thats mean lookin. Hows the 450 swingarm for keeping the front wheel down?

Louis Mielke
02-01-2009, 11:06 PM
Believe it or not, this bike is real balanced. Even with the shorter swinger this thing doesn't get outa control. And trust me it's not lacking for power.

I have to thank Halls Performance for help with the frame geometry. Jason really helped me get it right!

02-04-2009, 10:40 PM
wow, nice!! but for all that work, you could have just built a HRD zilla hybrid...


my 500r hybrid has orange fenders too, i'm plagiarizing your signature! :D

big specht
02-11-2009, 03:06 PM
This thread kicks ASS I'm going to buy one this weekend :Bounce Any ways what is the lenght of your swing arm now I saw that you changed it from the 1st version . I've been wanting to build one ever sense I was the write up in 3 wheeler :w00t:

02-11-2009, 10:22 PM
Lou, you are a master IMO, That bike is AWESOME!

One day I will get the chance to do one myself, till then
My stock 86R is gonna have to do :( LOL!

One question my friend, on your website, none of the pictures come up, is it just me, or is there a minor problem? Doesn't matter much, you have given us much to see here. I really hope you stick around for a few years, I would love to pick your brain when I am ready to do mine. By the way, is this the bike you used for inspiration?


I can see why you liked it so much, :beer

Louis Mielke
02-11-2009, 10:25 PM
Yup that's Tony Wyatt's 500. He actaully contacted me after finding my website and we chatted about 500 conversions.

My website has been defunct for a while now i really need to update it and get it going again.

big specht
02-16-2009, 02:51 PM
Why can't you use the 250r forks ???? I've been reading alot of differant treads about this conversion and I haven't seen any body say why you couldn't use them??????

Louis Mielke
02-16-2009, 02:58 PM
You can. There's lots of different ways to do it. I personally felt the 250r forks where just too short and spongy in combination with this frame and engine. It's all personal taste though.

big specht
02-16-2009, 04:45 PM
I plan on just using the bike for drag racing. Did you make a new swing arm??? If so what did you do with you old swing arm ????

Louis Mielke
02-16-2009, 05:55 PM
Just so happens I have the old ones still. I'll pm you.

02-16-2009, 08:01 PM
Old thread, old version of the bike. Here's the newer version. I'll get around to adding to the thread eventually. Thanks though! The new one is a million times better!


are those the same cr forks or are those different

Red Rider
02-17-2009, 02:57 AM
Louis, I don't know how you feel about your black fork protectors, but I believe they are available for your KTM85SX forks in the KTM orange. I'm also not sure how the KTM orange matches up with your current orange plastics, but it's a something to think look into if you're interested.

Louis Mielke
02-17-2009, 05:40 AM
Seddon, these are forks from the KTM85sx, and no Red Rider, I didn't know that they where availible in orange. I'll have to look into getting a pair for sure! The KTM orange isn't an exact match but its close enough for me! WHoohoo!

02-17-2009, 02:40 PM
Looks great Louis!

03-12-2009, 12:28 AM
louis i really like what your after doin to that trike man, that is one gnarly lookin pipe too haha, i wish i could have one too!