DR-Z400 suspension woes/fixes

[Gear]

There's lots of talk on the DSN_DR mailing list (Dual Sport News, DR list subscriber) about the DR-Z400E's actual "useable" rear suspension travel. It's evidently only 7.6 inches, and I'm not surprized.

First noticed the limited rear travel on my Z400E while riding the Arizona-Nevada strip desert 2 weeks ago on the hard dirt consecutive whoops. It was so annoying going through those with the back of the bike bucking up high and hard, the seat kicking up into my butt time after time. I felt like I was on a 1973 Yamaha 360 Enduro or something. My stock XR400 suspension performed leaps and bounds better than my new DRZ under those circumstances. Tweeking the preload/compression/rebound didn't help all that much, either. Very frustrating. I was bummed ?

So...I've ordered Kouba Links (#1's), a Race Tech 5.7kg rear spring, .46kg fork springs, and Gold Valves for both the forks and for the shock. I have the suspension all torn down, awaiting delivery of parts from Kouba and Race-Tech. At 185LBS, this is what R-T and Kouba suggested for me. Hope this works. I hope this little $550 venture improves things in a big way.

Anyone else out there cursing the stock suspension?

Any luck with mods/fixes?

[Novice@57]

I haven't had the problem that you are experiencing but find the seat hieght way to high.

------------------

2000 Suzuki DRZ400E and 1967 Triumph T120R Bonniville.

[DR.billZ]

I was going to say to add some rebound damping, but there isn't an adjuster for that. Sorry. A revalve of the shock can get you what you want.

[rparks]

That seems like an aweful stiff rear spring. I tried the Kouba links with the stock spring and it was bottom out city! I have read in several articles that a 5.4 or 5.5 kg spring is the way to go. Why such a heavy spring?

[*william*]

Where does this 7.6 number come from? Is this travel AFTER sag? That would make sense: 4" sag plus 7.6" travel = 11.6" total.

As far as "useable travel" that would be everything, including sag, because when you unweight the bike (say when it rebounds from a jump or a sudden dropoff) the wheel falls to keep in contact with the ground and the bike moving forward.

Hey Bill, that's funny! No adjustment for rebound damping, heh. Good one. ?

PS - Norm (the Kouba Links guy) is on our DRZ mailing list. He has mentioned before this "7.6in useable travel" number, whereby we then flogged him mercilessly.

(just kidding, but he IS tring to sell us those links)

------------------

William

00 DRZ400E

[This message has been edited by *william* (edited 10-24-2000).]

[cra-zmike]

Gear,

I got my springs from a friend who has an OEM supplier at better prices than the major suppliers. ...Mike

[PeteN]

7.6" of travel?!? "Useable"?!? I don't know what these guys are smokin', but my DRZE has at least 10" of travel at both ends and I use all of it. I'm not surprised that you found the DRZ a handful in the whoops with the stock suspension, but I think that you'll find with the new springs and a revalve that it will leave an XR400 in the dust. I have the same springs that you bought and I would recommend the steering damper also, because of the sharp steering head angle. I was running wide open 5th gear through 1-2' deep whoops yesterday and it was no problem.

[Gear]

rparks,

Reportedly, the Kouba links increase the leverage on the DR-Z's shock linkage mechanism, effectively reducing the stiffness of the rear spring. Norm Kuoba suggested that if I'm disappointed with the stiffness of the existing stock spring, then adding the Kouba links will necessitate a higher rate spring. He recommended the 5.7kg/mm rear spring in concert with his links for a rider of my weight and riding habit.

I'll let the board here know what the outcome is in a week or two when it's all complete and tested (fingers crossed in high hopes for success ? ).

[This message has been edited by Gear (edited 10-24-2000).]

[This message has been edited by Gear (edited 10-24-2000).]

[cra-zmike]

Gear,

I changed my front and rear springs to .46 and 5.6 kg with some clicker and oil height changes and it made a world of difference. Just trying to get rid of some low, mid harshness. No trouble bottoming except on BIG g-outs which is normal. I don't think 5.6 in the back is that heavy since stock spring rates are .43 and 5.3 KG. eventually, I'll try the Gold valves or have the suspension revalved. but for now It's way better.Check my post on "front end fix".

[Gear]

PeteN,

That's encouraging news about the improvement in whoops performance you found. Mine ought to do quite well after the mods, right? Can't wait!

Regarding the effective 7.6" travel, visit Kouba's site. He has some interesting and well-proven points relative to the, er, a-hem, rather short-ish travel. I don't yet fully understand it all, but I'm working on confirming/dispelling any truths/half-truths/myths.

cra-zmike,

I read your front end fix thread, and that, in part, is what lead me to the 0.46'ers in the forks. Thanks! What brand fork springs did you use; Suzuki RM250's or Race-Techs? What about the shock spring?

[dirtboy]

Can a stiffer rear spring be adjusted to give you more rear travel beyond only 7-1/1 inches?

[z4me]

Dirtboy - Yes, but you would do far more harm than good in changing your ride's geometry. Pushing the rear wheel down will cause your steering head angle to be even more shallow that it already is.

[Gear]

Update on my DRZ400E suspension set-up project:

After more than a week, the bike's still down

Received all the parts from Race-Tech (0.46kg/mm fork springs, 5.7kg/mm shock spring, fork and shock Gold Valves). The Race-Tech G.V. kits comes with a "how-to" video, which is quite amaturish but may be of some help.

Also received the Kouba Links. They weigh next to nothing, so I can rationalize all this by convincing myself I'm saving weight, too

So now the hold-up is the #%@*&% local anodizing shop. Blanchard Metal Finishing forgot to mask the shock bushing hole and valve-insert hole, so anodizing of my shock body cannot begin until Saturday (it takes 18hours for the mask to set up and dry). It was due yesterday! ?

Dammit, I wanna go ride and tell the world how much better (or not) the suspension gets! Guess I'll just have to wait some more.

-Gear

[Guest Guest]

Just test-rode my 400e after having Drew Smith (WER) re-spring, re-valve both ends, install new applied racing triple clamp which move the bars about 1" forward and about the same higher (I run Renthal CR hi bends), replace the steering damper oil with one weight heavier, (Also have a SRC fork brace mounted), and install an applied racing front brake hose. I just got a brand new bike! Much more predictable, handles whoops and big, sharp-edged hits worlds better. True one-finger front brake now...I plan to cut the lever down for just that one finger. Riding position (I am 6'0" and weight about 220lbs w/gear) is more comfortable too with the bars in a better "attack" position. Forks are excellent, damper stabilizes bike at high speed and absorbs 80% of roots/rocks/rut hits in the woods...it also helps with tree bashing on the bark-busters. I loved the fork brace before I had the suspension revalved and still love the effect... very accurate and precise... just aim where you want the front tire and hit it... it goes there. Still to do: LED tail/stop light modification...get rid of standard bulbs that can't take the beating. Install thermostat so rad fan (12v computer fan zip tied to left radiator) is automatic and manual for those long stop lights in traffic (or hot S.Jersey enduros in thick woods), Rewire light switch so I can kill all lights when racing (including turn signals), run only the head-light (for stealthy exits), or full lighting system for road use. I also want to experiment with making a "snuff or not" for the tail pipe so I can have a "super stealth" mode when I want it... A dream is also to come up with a motorizided compression/rebound clicker system with memories so I can change suspension settings from the handlebars... big project but could have huge benefits. ... U