KDXRIDER.NET

Did you modify the bottom mounting point on the shock at all? I've noticed the Showa is "boxed" on the bottom while the KDX is "rounded" and doesn't protrude near as much. I thought about rounding off some of the aluminum on the bottom of the Showa mount but I just can't work up the nerve right now to go for it.

If you shorten the shock with internal spacers then you will lose a lot of rear wheel travel. Why don't you just have some longer dog bones made at your local machine shop?

No I didn't mess with bottom , just shorten and shims(washers) on top to get width the same

shortening 1 inch gives about the same wheel travel as stock shock, as the Rm is 1 inch too long but a much better shock IMO.

Got the call today that my forks and shock are ready to be picked up at the suspension shop. Can't wait to get over there and pick it up. He gave a lot of quick technical talk over the phone but it sounds like I should have a great rear shock now. I'll update with pics as soon as I can.

I'm about to pull out what little bit of hair I have left. I can't get the RM Showa shock in place for the life of me. It is so close, but just doesn't fit (even after being shortened the 1.0").

Still too long?

Do they make lift kits for a kdx?

It's finally in but everything is in a bind. Had to file on the shock reservoir body and inside of the frame. It still rubs on the frame and pipe just before the junction at the pipe. Really ticking me off at this point. I'm about ready to pull it and put the KDX shock back in.





larger pic in gallery

All joking aside....keep us posted. My kdx is living vicariously through your bad@*s kdx

IT'S IN!!!!!!!!!!!!!!!!!!!!!

Finally. Now I have a larger shock body/shaft with an additional HS compression circuit. I'll say that I definitely ran into more issues than my two predecessors (osobad and bradF). By everything I have found, I do have a 2002 RM125 Showa shock and not something else labeled and sold on eBay as such. I have a full Pro Circuit exhaust with a Platinum II pipe and Factory Sound 304 silencer. I don't know what they have and that may be the reason I had fitment issues and they didn't (if they both had FMF).

Shock details...what was done to the shock: suspension shop shortened the shock by 1.0" which matched the KDX shock length exactly (I delivered both for his measuring) and went through and rebuilt/revalved with new fluids and seals, etc. The spring was replaced with the correct rate for my weight. The shop cross referenced a 2015 Honda 250 spring because the stock RM spring is too long for the shortened shock. With the Honda spring mounted on the shock body I have even adjustment both ways for setting the sag.

Mounting details...what an endeavor. I had to file/grind a little on the shock reservoir bladder and also on the inside edge of the frame rail. My big problem was the exhaust. I had to torch the silencer pipe and massage the pipe bend to give me a little steeper upward angle. I now have the shock mounted without any rubbing that I can see anywhere, but I'm not saying you could slide more than a dollar or two between the gaps.

The upper mount used the factory KDX shock bolt with (1) M12 washer on either side of the shock. That takes up the space due to the RM shock body mounting point being narrower than the KDX. On the lower mount I needed a M10 washer and a M10-1.25 nut since the RM lower shock clevis is not threaded on one side like the KDX. The KDX lower shock bolt may work; however, I have elected to order a second KDX top shock bolt to use on the lower mount. The stock KDX lower bolt would only engage 2 threads on the M10-1.25 nut so I wanted to use the longer top KDX bolt which is the same thread.

So far I am satisfied with the project, just was not expecting that much trial and error from the other reading I have done. We'll see how it works out once I can get everything back together. Let me know if anyone has any questions. Thanks for all the helpful information.

I have full FMF might be the diff in pipe rub. might try to move the washers to one side to space it over a little for frame rub. I had no rub marks on frame at all

Just a couple pics...

Two shocks side by side:


RM125 shock installed:


larger pics in gallery

Was it worth all the time and money ? How different is the rear suspension ?

Jaguar wrote:If you shorten the shock with internal spacers then you will lose a lot of rear wheel travel. Why don't you just have some longer dog bones made at your local machine shop?

Do you know how long the Dog bones would need to be? I wonder if there are some from a different bike that would fit.
Anyone know how much travel you would get with the full travel shock? Closer to the 12-13" of most motorcrossers?

I read your thread and was almost going to buy an RM shock, but I think that I might run into the same concerns as you. Have you heard of or explored any other viable manufacturer option besides the Suzuki RM?
Thanks,
-Thomas

Rusty, I don't remember the length of the custom dog bones but none of the aftermarket ones will do.
I don't remember exactly how I determined the correct length. I think I installed the shock without the spring, had someone sit on the bike, and then I measured the clearance between tire and fender and then subtracted an inch (assuming that the shock bumper was not fully compressed) and then calculated the extra dog bone length needed given the ratio of wheel travel to shock travel. Then bought some scrap iron pieces the right thickness and length and had holes drill in them at a machine shop. It worked great and I'll bet my grandmother that the ride it gave was plusher than any Jap shock can give. It had a Pro Circuit pipe on it and had no clearance issues.

I'm also running the RM125 Showa shock. The only mod done to make it fit the '95+ bikes was to change the lower clevis for a shorter one from a DRZ400 and putting a 45 degree bevel on the inside edge that is towards the linkage. More details and pics here: Full Showa conversion Was it worth it? Absolutely!

Just browsing Showa shock info, & wanted to add that what we ended up realizing is that SS109's suspension guy Donny had actually swapped on a DRZ400 / '98-'00 RM lower spring seat perch assembly, as it's approximately 4mm-5mm shorter than the '01-'04 RM125 spring seat to accommodate the shock spring length with a shortened shock. SS109 was running the full length '01-'04 RM125 Showa, but said it was 1/4" too long and had to be compressed to fit into the KDX frame/linkage confines, hence the shorter lower spring seat perch being necessary to keep the speung preload adjustment where it should be in the middle of the range.

I'll also add that the DRZ400 & '98-'00 RM125/250 Showa lower clevis is around 4mm longer than the '01-'04 RM125 clevis... The '98-'00 RM125/250 shock body and DRZ400 shock bodies are around 5mm shorter than the '01-'04 RM125 shock body... The DRZ400 shaft is around 5mm shorter than the'01-'04 RM125...
So I'm assembling a FrankenShowa out of various parts from these in order to have a shock upgrade that's 16mm longer than the H-Series KDX's stock KYB shock instead of 26mm longer (complete '01-'04 RM125 Showa). The complete DRZ400/400E/400S shock ('92+ for dual compression adjuster circuits FYI) seems to be the single best candidate if not wanting to buy multiple shocks to combine parts from into one hybrid FrankenShowa. I have yet to test fit the DRZ body, but hope to very soon. I've missed the mark to have my upgraded suspension ready for the big trip to Southeastern Kentucky (Redbird Crest / Elisha Creek rugged steep rocky mountainous Appalachian trail system), but on my return I'll have more time.

I've previously posted all of this info and more in SS109's thread which he linked above.