gear up or gear down?

[Nevada Sixx]

ok,,my brother said he nearly go killed on a small double cause he came up short, i asked him if it was suspension fault, and he said no,, he just couldnt go fast enough on his 220 to make it..it was only 30 feet, but it was after a tight turn with about 70 feet run and go if that much... would it be better to get up or gear down to get more speed over a short distance like that?

 

[OZ_dirtrider]

It all depends on the approach to the corner and how much speed you can carry mid corner, the tightness of the corner, ruts and the line you are going to take driving out.
If you know that there are double coming of the corner, gear down prior to the corner, slide in the corner ( i tend to load the rear up), then mid apex to just pass, drive out keeping your line.
Someone wise said...smooth in and smooth out...damn works!

Oz

 

[mprest4]

hes not twisting the throttle hard enough if he cant jump 30 feet with a 70ft lead up. he should be able to go hard out of the corner in second and shift to third on his way to the jump. just slip the clutch in the turn to get the revs up.

for gearing i have a 200 and i have tried 12, 13 and now a 14 tooth sprocket.
i like the 14 tooth the best for mx. less shifting and very rarely have to go down to 1st gear. cheap mod too.

 

[Nevada Sixx]

oh yea,, when i say gear up/down, im mean what size sprockets,,i understand that a larger front sprocket will make the bike go faster on top,, but we need faster acceleration off the bottom since its a short run and go.. i wasnt sure what the trade off will be..

 

[Midhigh]

I ride my 96 KDX at the track all the time. I did two things. 1. Raised the forks about 1/2 inch in the triple clamps. Corners better and faster. 2. went from a 47T in the rear to a 51T. I can tell a good difference in the amount of power and punch I have out of the corners. The tradeoff, however is that what I normally would take in third now takes an extra shift and I take in forth. But I like the punch it has down low alot better.

 

[Reesknight]

I don't know about KDX's on an MX track but I find it easier and smoother to go into a turn a gear high and slip the clutch for power(YZ250). With that being said, if you lower your gearing, each gear will top out sooner with less top speed causing a quicker shifting requirement to reach the proper speed. Try a higher gear and slip the clutch with the gearing he has now and see if that helps before changing the gearing.

 

[Nevada Sixx]

midhigh,, do you think gearing your bike down caused you to have more speed by the time you got to the jump?

 

[Midhigh]

I just got back from the local track. My favorite corner is a hard right and then 15-20 feet out of the turn is a step down jump. I noticed today that the speed I could take it at and then come out of it with sent me well down the hill. I don't normally carry that down hill jump. So to ans. your question. Yes, I think I get more speed into and out of the corners, thus giving me more speed at the jump. I must say, however, it takes more shifting to get that speed. And the line I take is wide and a well banked. I have been forced inside on occassion and the lower gear is hard to regain your speed for the jump (shifting alot). But, I still like the way it comes out of the corners geared lower.

 

[Nevada Sixx]

midhigh,, do you ride on a real mx track? doing basic doubles (25-30ft)and whoops? and does your kdx do pretty well at it, maybe even good enough to win or place well at the beginner 250 class?

 

[Mike Hubert]

I had a KDX and I dropped a tooth from stock on the back sprocket to 3rd gear would carry further to make the longer jumps. Don't be afraid to stay in 3rd coming through the corner and as others have said use the clutch to control your RPM.

 

[Midhigh]

Yes I ride on a real track. I ride at cooperland in stillwater ok., motorcycle raceway in OKC, & Redbank 51 MX park in Stillwater Ok. all are very good MX tracks. Redbank 51 has two killer 40foot table tops that I take all day.

I love the way my KDX rides. I rode a friends 02 KTM 250 at the track. It was better in the whoops, but it beat the crap out of me. I liked the shifting and cornering of my KDX much better. My riding partners have a CR 125 and a YZ 400. When the 16 kid is on either bike I can hold him off for a lap or two. But evenually get passed. But his dad on the YZ 400 I can stay with all day. I am 38 and just don't have the guts as the younger kids. the KDX suspension is a little soft, but if your not landing flat it doesn't seem to mind. I think a KDX set up right and with a good rider could hang with the MX machines some. But it's not going to win you any series.

I must also agree with mike. don't be afraid to come into the corner hard using your clutch to keep that higher gear & RPM's up then coming out very strong into the jump.

 

[Bazooka Joe]

As a general statement, it is not a good idea to regear for one particular jump, but rather evaluate the overall bike's ability on a wide variety of obstacles.

In the KDX's case, either dropping to a 12T in the front, or a 50T in the rear (avoid the 49T b/c it cause weird things with chain length and adjustment range), will bring the gear ratios together that little bit closer and help the KDX pull the next gear w/o falling out of the power.

 

[limitless]

i have a question...often i find myself shifting down to first or second cause second is just a slight to tall (cant quite fan the clutch & keep power) i rarly get out of fourth.....so would i need to goto a 12T or 14T?

 

[Jaybird]

Try not to make your gearing change with the front CS sprocket if you can help it. Make the change with the rear.

Learn to slip the clutch and the original problem will go away.

Riding MX with a woods bike puts you at a disadvantage to begin with, riding it like a woods bike makes it even worse.

Gas it.

 

[RTL]

Nevada, beware of what 'works' for others and let your piloting experience tell you what may or may not work for YOU... The nature of your questions leads me to believe that your experience level is minimal at this point, thus my 02. This is not ment to be a slam to anyone, so take my 02 with a grain of salt...

Bike setup must conform to riders abilities/preferences. Suspension, jetting and gearing should be customized to meet a riders abilities/preferences and each can dramatically effect your machines performance.

For example, Midhigh might use gearing to adjust 'punch' where I might change jetting to get a harder or smoother hit earlier in the rpm range while retaining my wide ratio gearing.... Reesknight might carry a little more speed into a corner, round it off, and feather his way to a crowd waving launch... ALL of which may or may not work for you!

So, you could have 999 different responses to your question and they could all be correct for that particular rider/machine. I know a few local pros who could master most tracks on a pogo stick.. Take examples from other riders and learn what works for you, but do not get stuck on having a specific formula for success, it simply does not exist. :thumb:

 

[Bazooka Joe]

Limitless-
You would want to drop a tooth on the front. However, as J-bird sez, avoid dropping a tooth on the front sprocket. Switching to a 12T sprocket on the KDX increases the wear on the swing arm buffer pad, although you probably will not notice any increase in the wear if your weight is high and your ride aggession is slow. ie- fat + slow. ;)

J-bird, A motobike in the woods is not neccessarily a disadvantage. In contrast, motobikes (with some woods mods) do have some very positive attributes which can actually be an advantage in many situations. It's hard to disagree with light weight, great handling, top shelf ergos, plenty of power, and so on. Of course, motobikes are probably not a good choice for novice riders.

 

[limitless]

thanks for the info jaybird, i was thinkin it would be cheaper to do the front to see how it feels and if i like it go back to the 13T and swap the 47T for a 50T.
bazooka - skinny & fast.....well skinny anyway. :)

 

[ride_red_15]

But to reply to Nevada...if he cant clear a 30 foot jump with a 70 foot run, he needs to work on his technique...not his gearing.

 

[Jaybird]

Joe, I agree with your description of a motobike in the woods, I was reffering to a woods bike on the track.

Limitless, not only can the 12T cause trouble on the components mentioned, it can also help to make your chain wear faster, which in turn wears your sprockets faster.

 

[G. Gearloose]

Nobody's asked how modified this 220 is...or even jetted.
These is some consensus that the stock 220 runs flat on top,
If it is in stock form, just gearing down so it gets into the upper rev's sooner, may be less productive on the 220 than it would on the 200, or most any other bike.

 

[Midhigh]

RTL,
I must agree with you! I have have friends that didn't understand why I geared my bike the way I did. I good reason, I like the way it rides that way. It fits me. I jumped on a friends 02 KTM 250 and went a couple times around. The first thing I thought was how it's not my bike.

Set your bike up for you. Thats the only way you will be happy with the way it rides and runs.

Good words RTL!!!!

 

[Bazooka Joe]

Gearloose,

Good point. I forgot what a stump puller a stock 220 is. My 220 stayed stock for about 22 minutes after I got home; I immediately began experimenting with the 200's larger carb, and the stock 220's became 36.5mm within a couple of days.

Another thought about jumping a stocker KDX.... You need to be a little careful sometimes if the bike is 100% stock. In stock tune, the fork is pretty soft and the rear is stiff in comparison. With these two situations combined, you can get some mean rear end kick if you are not prepared.

To answer the Q about dropping to a 12T for an experiment to try out the different ratios... Perfectly good idea! In fact, if you would want a 12T Sunstar for such an experiment, I have one laying in the toolbox which was used exactly for that reason. I'll send you that one for $5 includes shipping. If interested, email = [email protected] Or another option- order a 12T from Rocky Mountain for $7(?). While you're ordering, you might as well get the 50T because you'll most likely approve of it. (get the $15 steel rear sprocket) Keep in mind this- the 12T will use the stock length chain, but the 50T will require two links longer.