Need Help with Dimensions for USD conversion

Are you going to use the XR650R shock shaft on the CR500 shock?

You have to use the XR650R shock shaft, as the CR500 shock shaft is much longer. It is still work to get the shock in with the 650 shaft; it is an impossibility with the CR shaft, at least from my experience (I tried).

If you don't want to spend the money for the CR shock, but would like the longer travel that it offers, there is a way. If you use the seal head from a KX500 (I used a'96) in place of the XR650R seal head, you will get the increase in travel that you get with the CR shock mod using the stock 650 shock. I did this before I was able to score a cheap CR shock off e-bay.

Yes, as said, the CR500 shock shaft is way to long.

The CR500 has a larger diameter shock body so, the need to use the larger diameter Valve and CR500 seal head/rod guide is a must. The CR500 seal head is shorter letting the rod travel further and with the larger diameter shock body, this makes for a larger fluid volume. This reduces shock fade in long warm desert races but, the main reason for wanting the CR500 shock body is for the high speed compression adjustment. Down side is the CR500 valve is that it is backwards to what the XR650R needs. Off the top of my head I think the CR500 valve is 34mm compression and 36mm rebound; with the XR650R valve having 38mm compression and 34mm rebound. The CR500 valve also has the porting in the valve way off with small compression ports and large rebound ports. Backwards to the XR650R valve. RaceTech sells a Gold Valve with one side 38mm and the other 34mm. The valve can be used with the 38mm side as compression and now you have the right valve to use in the CR500 shock body for the XR650R. The CR500 and XR650R have much different swing arm to shock linkage ratios. This makes for a big difference in valve velocity. So, a much different shim stack needs for the different bikes, in the end you need close to the same shim stack you had is the XR650R to begin with. I was thinking you would need stiffer shimming because of the somewhat greater fluid flow through the Gold valve but, I went to far thinking I would try and clear the 80 foot ( I don't think it's that big anymore) table top at Star West. The problem with this is the CR500 slow stack adjustment is half of the XR650R adjustment so, you have to get the shim stack much closer to spot on or even a little soft. Making the Baja 500 shim stack; or the CR500hybread shim stack much closer. Or even the Baja 1000 setup being perfect for all around use. The rebound responds the same as when in the XR650R shock body. In the end I think it was close to 5mm~8mm (or was it 10mm), shock is longer and with a linkage ratio that is about 5/8" or maybe it was closer to an inch rear travel. I need to write this stuff down. I shorten the rebound spring in the forks and shimmed the springs some pushed the forks into the triple clamps to get back to the right rake but, it isn't what I want so, maybe going to CRF450R forks next. I really like the flex of the stock forks to absorb the hits but, I need the rake to be right. I know for most of you on this thread I didn't state anything new. But, in your final compression shim stack setup remember that the CR500 slow stack adjustment is much more aggressive then the XR650R adjustment. :prof:

ya i know. i meant to post this link in a DIFFERENT thread. unfortunately i clicked on a thread (yours), that looked like the one i wanted to post it in.

I've got another question. What type of headlights and/or numberplates should we make these tripleclamps accommodate? Would anyone want to run a CRF250/450X headlight? Stock XR headlight? A CRF250/450R numberplate? I will probably run a 8" Baja Designs racelight myself, but I have all of the dimensions for each of those other headlight/numberplate mounts. I just don't want to clutter-up the tripleclamps with mounts that nobody will use.

For me, I doesn't matter. I am running an 8" HID racelight, but I have mine frame mounted. I would think that you should set it up to use a more modern X headlight assembly, as the stock 650R assembly just attaches to the forks anyway. I haven't really looked at how the X assembly attaches (although I know it is bolted on), but I am sure that there is a way to accomodate both methods. Perhaps an exchangable piece on the lower clamp that can give you either the proper holes for the 650R headlight shell, or switch it out for a piece that has the properly threaded holes for the X assembly.

I'd like to see how you have that 8" headlight mounted to the frame.

I'm thinking like you, that if people want to run a 35W headlight, they might as well get a newer, better looking one for a CRFX. The CRFX plastic has two holes in the plastic and the pins are cast into the lower tripleclamp, so I'd just need to have those little bosses machined into it.

I am finishing up the mounting system next weekend. We are trying to work up a system so that we can still use the light with the 'conventional' fork brakets on another bike if we have to. I have also incorporated my stabilizer post into the frame bracket. I'll post pics when I get the system all wrapped up and it passes durability testing (after Labor day weekend).

Durability testing? Labor Day weekend? Come awn. Send me a PM with some pics and a little more.

I have a team put together for an upcoming 24hrs race. We are going to run from 8:00 pm next Sat. night until 8:00 am the next morning to make sure that my fabbed light brackets will hold up, everyone else's wiring holds up, and we've got our radios working properly.

We had team members last year with new setups the day of the race and they failed, costing us valuable time. Therefore... durability/performance testing prior to racing!

As soon as I get the mounts finished up this weekend, I'll post the picks. Then if they fail, I can post those pics for public ridicule!:naughty:

Looking forward to seeing whatever you've come up with.

I've got an update regarding the tripleclamps and lighting. I just talked with Tex at Baja Designs about incorporating a quick-release mount for their 8" headlight into the tripleclamps (instead of using hose-clamps on the fork tubes). He's going to send me a CAD file and then I'll post some screen captures of whatever I come up with.

After spending some time working with the CAD file that I got from Baja Designs, it doesn't really seem worth it to modify the tripleclamps for custom mounts if they go into production. If I end up just making a set for myself, I'll have them made with the mounts, then cut up the BD light mounting frame to make it work.

SCOTTS and BRP have decided not to produce these tripleclamps due to a perceived lack of demand, which I completely understand with the 650 not being offered for sale in '08.

What do you think a local machine shop could make those for if you gave them the specs?

I'm in the process of finding that out and would appreciate input from anyone with that kind of experience/knowledge.

I've modified the design slightly to make a version of these tripleclamps more affordable to make a one-off run. There's really no reason why I need to make my own handlebar clamps, so I'm going to use an off-the shelf Scotts/BRP submount handlebar clamp assembly for a CR/F. I also made another change that will allow me to reuse the stock XR steering stem. The only parts that will actually need to be machined are the upper and lower tripleclamp.


I've got an update for you on my set-up. I just did the conversion on my sons bike like I did mine. 1- Evolution Suspension has a new bearing and race that is just the right size. It need no washer to space it, and fits exactly flush with the top neck tube. 2- I installed a triple clamp from an 06 model bike and it now has full turning radius. The steering stops are in a different location than the stops on the older CR/CRF's. Full turning radius and the stops contact the meat of the frame almost near the stock contact point, not the lump of material on the front of the tube.

Cool. Can you post a few pictures to show us what you're talking about?

I'll snap some pics right now. I don't know how good I am at uploading pics

? Maybe I can email them to you and you could post them? You'll see that I trimmed the tree before I even tried it so I could match my tree. I should have checked first, because it looks like it would have taken only the slightest trim to make it work. Now the pointed part of the stop hits the meat of the frame not knowing this was going to be the contact point. If I would have left it stock it would have had a nice rounded contact point. Still better than hitting the front of the neck like on mine. I bought a newer tree for mine now so I'll make it better this time.

Sure, send the pics to

Let me know if you got the pics?

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