CR500AF update

[dogger315]

I'm slowly but surely assembling my CR500 hybrid.

I gave up on the back ordered Pro Circuit linkage and decided to go with
an OE assembly for now.  Everything is going together pretty good so far.

Here are some more pictures.

dogger
 

[keeptwostrokesalive]

That is going to be one sexy bike.

[SachsGS]

Looking good! I wonder what the guys at Honda think of more and more of these hybrids being made?

[ACMX]

Super cool man

[ford832]

Now that's too freakin' cool.What issues have you run in to,or expect to have to deal with?

[Coop]

Very nice!

[2smoker]

keep them coming! gnarly!

[dogger315]

Thanks guys.

What issues have you run in to,or expect to have to deal with?

Aside from the known problems of stuffing a CR500 engine into a CRF250 frame
which are all known and dealt with during the frame modifications, it looks like I
am going to have a clearance problem between the shock spring and the engine
case and between the airbox boot and the shock spring.

Both of these problems are caused by the titanium shock spring.  The spring has
fewer coils than steel but each coil is larger in diameter and the overall diameter
of the spring is about 5mm more than a steel spring - just enough to foul the
case and boot.  Of course the easiest fix would be to swap in a steel spring, but
I'm not ready to take the easy way out just yet.  I can fix the airbox boot/spring
problem by removing the 10mm spacer I installed between the VForce and the
cylinder to boost low end.  I don't have a solution I like for the case/spring yet.

That's the challenge with these projects, and half the fun.  I'll keep you posted.

dogger

[JohnN]

Dogger,

Your bikes always have that factory bike look and feel to them, with everything looking absolutely new and original. Awesome job on this one.

What's the deal with the suspension? It looks like it's a couple of grades higher than the standard bikes have on them...

How bad is the rear spring to case overlap? Even from the photos about it looks like it will hit. Can't wait to see the way you solve it.

Looking forward to more photos.

[scotty dog]

WOW!!!!! You are the man Dogger!! That is gonna be the nicest 500AF on the planet...... cant wait to see it finished..

[dogger315]

Thanks for the big thumbs up.  This is a project I have been planning for a long time and wanted
 to go all out.  My goal is to build a bike similar to what team Honda would field if the open class
was still around, so I am using every trick part I can find. 

What's the deal with the suspension? It looks like it's a couple of grades higher than the standard bikes have on them

Good eye John, the suspension is Pro Circuit's Works Showas.

What you can't see is how "stout" the engine is.  I built it from all new parts based on the 2001.
The transmission is a rare HGA close ratio unit, all the rotational and frictional surfaces have had
an REM Isotropic slick/hard coating applied. The crankshaft has been balanced, Hinson clutch,
multi map programmable CR250 ignition, Eric Gorr top end, VForce 3, Keihin 39.5mm PWK carb and
a Pro Circuit pipe and silencer.  It should yield approximately 65-70 "rider friendly" hp at the CS -
way more than most mortals can use, but what a hoot to have on tap 

The lessons learned from this build will help with my next project:  A CR250 hybrid using an equally
trick 2001 CR250 engine and a 2010-11 CRF250 frame.  The engine build has already begun.

dogger

[EJ]

Awesome!
Good luck, and have fun with those lovely bikes you build!

[sticky throttle]

Thanks guys.

What issues have you run in to,or expect to have to deal with?

Aside from the known problems of stuffing a CR500 engine into a CRF250 frame
which are all known and dealt with during the frame modifications, it looks like I
am going to have a clearance problem between the shock spring and the engine
case and between the airbox boot and the shock spring.

Both of these problems are caused by the titanium shock spring.  The spring has
fewer coils than steel but each coil is larger in diameter and the overall diameter
of the spring is about 5mm more than a steel spring - just enough to foul the
case and boot.  Of course the easiest fix would be to swap in a steel spring, but
I'm not ready to take the easy way out just yet.  I can fix the airbox boot/spring
problem by removing the 10mm spacer I installed between the VForce and the
cylinder to boost low end.  I don't have a solution I like for the case/spring yet.

That's the challenge with these projects, and half the fun.  I'll keep you posted.

dogger

Dogger, great build, What solutions did you come up with to run the ti. spring? I'm having the same problem with a steel spring at 5.4 spring rate. Your help would be greatly appreciated.

[dogger315]

I ended up finding a Ti spring from a different manufacturer (RCS), that had the same OD as a
steel spring.  Even with that, I had to radius the case.  To do that, use a grinding disc the same
OD as the spring and run it off the center line of the case, I took off 2mm.  Remember, that
part of the case is not part of the transmission seal, just surrounds the swingarm pivot bolt
passage.  After grinding, hit it with 320 then 400 grit wet sandpaper and finish with WD40
and a Grey or Green Scothbrite pad to return the surface back to normal.

Here's a picture:



dogger

[dean100yz]

Is there a way you can follow threads??

Im in love with this! My dad & me are the same, will always get things as original or perfect as possible.

Looks like you have an amazing piece of work there. Thats gotta be pulling 55+ at the rear minimum