KDXRIDER.NET

Since I bought it last year (my 1st 2 stroke) I've struggled with the power delivery on my 98 KDX 220R. Mostly when it comes to standing on the pegs. I notice it mostly in 1st and sometimes in 2nd. The power is pretty abrupt and I just can't maintain a decent stance.

I'm pretty good about smooth throttle inputs, in 2nd I can keep the bike purring over nicely and this is usually the gear of choice for the tight single track I ride here in NW Oregon. However, 1st is a different matter, open the throttle a little on the pegs and the bike literally pulls away from me (and I'm trying to ride with my hips in front of the pegs).

I'm coming from a 4stroke background and stand on the pegs on my KTM all the time in 1st and 2nd. I had a friend who rides a DRZ400e try the KDX and he had the same comment, that trying to stand on the pegs in 1st was next to near impossible. He absolutely hated it.

The other thing I've noticed is that the bike revs out too fast in 1st, almost as soon as you're going, the bike is topped out and it's time to upshift. I rode a 200 with a 240 kit last week. I couldn't tell what rear sprocket size it had but front was I believe a 14 tooth. I'm stock, 13/47 so going 14/47 would obviously lower the gear ratio and allow the bike to rev out further in 1st. However I see a lot of people recommending a 12 tooth front. Since I'm running mostly in 2nd, this sounds actually more intuitive to me as it will let me run 2nd sooner and start using 3rd. Of course it would relegate 1st to super slow stuff and I'm just curious on the whole power delivery and standing on the pegs existing issue I'm having in terms of making final drive changes.

It is of course possible the bike is bogging down on the main as I'm having problems with my new carb setup. The 240 I rode with the 14tooth would rev out way way further in 1st than mine but it also seemed smoother in 1st also.

There is a lot of good stuff though, I replaced, repacked and adjusted the steering bearings last year and got it adjusted spot on. Turning is amazing, just look where you want to go and give it gas and it just goes there, never ridden anything quite like it. When I was riding my friends DRZ I kept getting close to running into trees/etc as it just doesn't steer even close. Power delivery on the DRZ was way more manageable however.

Try a 12T

When your carb is tuned right you probably won't use first much...It's for literally crawling around....The beauty of the KDX is it's ability to lug around...Yes it still rips up top, but it's a piped 2-stroke and that's what they do....The KDX just happens to run on the bottom as well.

Sounds like your riding stance is too upright/uptite. Try bending the knees more and crouching over the front- get used to the bike moving around under you, if the front end lofts let it come up to you under control. Stay loose, but use your knees to hold on when necessary. A stock KDX is not an abrupt bike...no way, no how.
Like Fuzzy said, first gear is like a compound gear found on old pickups, use it to get moving then immediately shift to second. Lots of places I use second to start, if the ground is level or down. On flat ground first is a waste to rev out. Even MX bikes with a higher first are usually started in second from the gate...

You shouldn't have to change anything on the bike for the problem you describe IMO, except maybe your bar height and position if that is keeping you knotted up too far down and back.

I'm 6'5" and have the same problem, it feels as if I am way too 'top heavy'. Under sharp throttle or engine braking it affects me the worst. I have found by bending my knees slightly more and adopting the 'attack' position (elbows pointed up and out) it has helped alot. Also where on your feet do you ride ?? Arches or balls ?? I try to stay on the balls when standing alot and it makes a pretty noticable difference for me aswell.

crazybrit wrote:The other thing I've noticed is that the bike revs out too fast in 1st, almost as soon as you're going, the bike is topped out and it's time to upshift. I'm stock, 13/47 so going 14/47 would obviously lower the gear ratio and allow the bike to rev out further in 1st.

I think you'll have to try changing your gearing for yourself in order to really get the feel for what you need...

However, FWIW, I tried a 14/50 combo someone got off some frp site...don't much care for it. Don't like it at all in fact. The stock gearing, like you mentioned you are running, is better IMO. The thinking was that the 14/50 would only slightly lower the gearing and keep the bike in third more often on the trails. I get what people are saying about the combo (I did a similar thing on my WR and love it), but find the stock gearing along with the RB mods to be just right for the Coast Range. I have still to try it in the Cascades of Washington.


I don't think you should go to a 12 in the front, knowing the woods you ride in like I do, but as I stated in this post - I think you'll have to try it out for yourself.

Good luck crazybrit.

Interesting that you mention this . . . I've been trying to get good at exactly what you describe, and as it turns out that as the momentum of the bike pulls directly forward and at an angle that didn't necessarily match how my arms/hands are pointed (esp with a few fingers over the front brake/clutch).

I rotated my Renthals up and forward a bit and this helped. I need to raise the handlebars a bit higher for even better positioning. Rockymountainatv.com offers a "universal riser handlebar kit" that I'm going to try to help even further.

The more you practice with body positioning the easier it becomes. I'll get going while standing w/ knees squeezing the bike. Right before I stop - and fairly abruptly with both brakes - I position my body rearward. As I come to a quick stop my body shifts forward, and just as I stop my body is leaning forward w/ momentum. I sortof catch the forward momentum as I get the bike going again. It has taken some getting used to and I've spilled the bike more than once doing so but have gotten much better at it. This technique (which is not mine, BTW) has helped me "learn" how to use body momentum under these conditions.

I actually do this in second more but I'm geared 12/47 which I found to be my gearing of choice. First is for plowing gardens . . . wait, I don't have a garden!

And now that I've installed an RB head with even more compression, I need to relearn a bit!!

Sounds like a gearing and jetting problem, I tried a ride on a friends yz250f and his bars were so low it was impossible to stand, I felt like my hands were down by my knees. OH! and Im 5'6" I run CR HIGH MINI Bars, the more I sit the more I ride like shtt. I use my knees to clamp and hands to control the levers and throttle. works great when your tired. I also tuned my KDX to run in 2nd,3rd accelerating smooth from idle to mid range then as you get between mid and 3/4 the hit kicks in. I ride in conditions that require good 1/4 throttle response and control. The KDX is the most tune able bike I have owned. good luck invest some time and reep the rewards.

I put bar risers on my bike, it helps a bit.
I also try to do what JEB describes- I think of it as "collapsing" onto the seat under braking just before the apex of a turn and then on the throttle and getting back up forward. Sounds good, anyway.
What usually happens is I blow the corner, loose my front over the berm, or I drive out of the corner into the trees- all while my A class riding buddy is on my tail yelling "stand up, STAND UP"

I think the KDX is not conducive to standing. The seat is just too inviting. In the real tight stuff I think I do best sitting or my butt 2" off the seat, gripping with my knees and with my head forward and down and just railing it. The trick is to maintain speed THROUGH the corners- no brake sliding.

I don't think I ever use first gear for anything, mostly third and up.

I have found the same issue on my stocker KDX220 but not as pronounced as you describe until...

...until I've been riding for hours and my hands are numb and my forearms are aching that is. While it is somewhat sensitive in 1st anyway it gets more pronounced for me as I loose fine motor control getting tired. Second and third are my best gears...the KDX seems to love those two in the tight trail NW.

Good info from you guys though...this should go in the "Riding Technics" forum.

Waz

Also, do squats, push-ups, pull-ups, cardio, and core exercises. The KDX IS fast/light enough that it's hard to hold onto. More so than the DRZ, no where near as hard as a 250.

fuzzy wrote:Also, do squats, push-ups, pull-ups, cardio, and core exercises. The KDX IS fast/light enough that it's hard to hold onto. More so than the DRZ, no where near as hard as a 250.

This is I think the problem. I'm in fairly good shape but as you say, there is a lot of hit, especially in 1st gear. It's a lot more manageable for me in 2nd. Just got back from 40 mins of cardio at avg 145 h/r but I agree, being in shape helps. I think getting the jetting in place and playing with the gearing may help also, but I think this is the main thing. I'm just not used to the power of the almighty 2-smoker ;-)

thanks for the advice everyone, really appreciated.

cheers!

Am I missing something here?

Last thread had you complaining about low power after all that RB magic you had done, now you're complaining about abrup delivery - you're either crazy or you have some serious jetting to do

IMO, the getting in shape stuff is OK, but the only way you really get dialed into riding is just to ride a lot, that way the right muscles will get tuned, your reflexes will tune, and your cardio is generated from the muscle groups that are actually being used for riding. More riding experience with some thoughtfullness will make the problems you have a thing of the past.
I'm pushing 60 and ride once or twice a week on the most challenging trails I can find. The road bicycling, the hiking and wieght lifting I've done is both boring and pales compared to the dirt biking for conditioning. I think mountain biking is the closest thing for getting in shape as it trains the eyes and reflexes too.

I'm an overly opinionated dufus I guess - but with enough riding experience you shouldn't even think about the bike, you think about terrain and everything machine-wise becomes pretty much autopilot -

BTW, at my age, full-on riding, sucking air big-time, hauling-arse in tight terrain, roosting young punks in the process (of course) generates a max 110 B/M. Crap, I'm practically hibernating while I ride!

kawagumby wrote:IMO, the getting in shape stuff is OK, but the only way you really get dialed into riding is just to ride a lot, that way the right muscles will get tuned, your reflexes will tune, and your cardio is generated from the muscle groups that are actually being used for riding. More riding experience with some thoughtfullness will make the problems you have a thing of the past.
I'm pushing 60 and ride once or twice a week on the most challenging trails I can find. The road bicycling, the hiking and wieght lifting I've done is both boring and pales compared to the dirt biking for conditioning. I think mountain biking is the closest thing for getting in shape as it trains the eyes and reflexes too.

I'm an overly opinionated dufus I guess - but with enough riding experience you shouldn't even think about the bike, you think about terrain and everything machine-wise becomes pretty much autopilot -

BTW, at my age, full-on riding, sucking air big-time, hauling-arse in tight terrain, roosting young punks in the process (of course) generates a max 110 B/M. Crap, I'm practically hibernating while I ride!

I totally agree. I'm in good shape and after 50 miles of single track on Friday, Saturday and Sunday I felt like someone had beaten me with a stick. Being in shape helps but as you say, it won't train the same muscles (well, I guess it could if you designed your training regimen to closely mirror mountain biking).

2001kdx wrote:Am I missing something here?

Last thread had you complaining about low power after all that RB magic you had done, now you're complaining about abrup delivery - you're either crazy or you have some serious jetting to do

Please go back and read again. I said, that I've *always* had this issue with the bike in 1st gear. It revs out real fast in 1st and is hard for me to control. It sounds like I maybe need to bring 2nd down and make it more useful and relegate 1st to ultra slow stuff.

What does this have to do with the RB changes? If you want to call me crazy, thats fine but it seems a bit unnecessary and asshole-ish.

I appreciate the positive comments from everyone else. Seems at least a couple people found the thread useful. I think it's probably that I'm just not use to the power delivery on the bike, too much riding 4 strokes. It really does want to pull my arms out of the sockets in 1st but it's always been that way.

It has a wide ratio trans w/ a granny first gear. I'd say you rarely want to rip into it in 1st gear unless you're absolutely ready to take off like a rocket. It's really meant for just crawling around below 1/2 throttle.

Gear reduction can also be referred to as torque multiplication. Ignore these actual numbers, but let's say the KDX has 10ft lbs of torque and a 4:1 first gear. That equates to 40 ft/lbs of multiplied torque in first. Now lets say a 500 has 20 ft lbs of torque and a 2:1 first gear. That equals the same torque multiplaction, and you've got to be a MAN to stand on a 500 WOT in first. Again, those numbers are innacurate, but hopefully you get my point. More torque multiplcation occurs in first gear on the KDX than MOST other bikes.

fuzzy wrote:It has a wide ratio trans w/ a granny first gear. I'd say you rarely want to rip into it in 1st gear unless you're absolutely ready to take off like a rocket. It's really meant for just crawling around below 1/2 throttle.

I'm not ripping it in 1st, neither was my friend who rode it. I'm sure I'm never over 1/2 throttle on single track but the response is just very abrupt. Braking hard and then coming on the gas in 1st is just really abrupt. I'm going to try the comment about body position when braking as it does feel like it's a momentum issue. Feels like the bike just takes off and I'm going to fall off the back as soon as I put any throttle on if I'm standing.

Maybe it's compounded by jetting also, I'm definitely having jetting issues (that I need to resolve) with the new RB carb but like I said, it's always been like this.

The only time I go over about 30% throttle is when I'm seated and running on gravel roads etc and then I'm surprised how fast it revs out with the stock gearing. I need to find what the rear spocket was on the 240kdx I rode, front was 14 and it would rev out maybe 60% longer in 1st.

Lots of things to work on here. Riding skills being just one of them. Off to take a 4 day class in LA desert on Nov 1st with Admo, looking forward to it, though it's on a DRZ. 525EXC was another $100 a day (ouch).

I just started riding a KDX220 so I am no expert, but I did notice the same issues when I first got the bike. I think the single biggest help for me was the 607 reeds. The bike comes on pipe quicker and to me, is easy to manage. Now I can use 1/8 throttle were I needed 1/4 before. I also went to a 13/49 gearing and I like it much better than the 12/47 I previously had.

One think I have noticed about the KDX is ,I don't need to stand near as much as I did on other bikes. I grew up riding MX bikes and was always in the habit of standing on the pegs with the boys right over the tank for hills. I have found that on the KDX I just slide up on the seat until the boys feel the seat tank overlap for most hills. Of course there are still quite a few circumstances that require standing and using body english to navigate some rough stuff.

Keep tinkering with it, until is suits your style.

"If you want to call me crazy, thats fine but it seems a bit unnecessary and asshole-ish"

I'm very sorry about that. Did not mean to come off asshole-ish.

In my opinion the KDX has such a low, granny first gear, that you actually should never be WOT in the woods in first. I'd keep first for the real slow stuff, then if you need to go WOT put it in second.

Ever since I got the RM I've gotten some perspective on the whole gearbox idea. I don't by any means ride tight woods, but the RM takes an active left hand and a steady right to do anything successful. 1st gear on the 250 is equal to somewhere between 2-3rd gear on the KDX. It's THAT long, so if i were to ride a KDX now, I'd probly never even use 1st.