KX Riders
Maintenance & Technical => KX500 Original => Topic started by: woodsy on May 07, 2003, 03:52:32 PM
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Hi folks;
I have been spending ALOT of time on my KX500 and have a problem that I have, to this point, been unable to over come. I am an aggressive woods rider, weigh 224 (fully geared). My K5 is a year 2000 that was new (maybe 10 hours on it) when I bought it this spring. It had Dunlop 752's front and rear when I purchased it and I have since worn out the rear and replaced with a Michelin MP11 (hooks up WAY better then the Dunlop did). My Mono is set at 4 inches race and 1 inch static sag - 12 clicks on compression and 10 on rebound. Forks are 10 and 12. Both have stock springs/valves/oil. My forks are set at 2 millimeter above the triple clamp. The bike now has over 100 hours on it and feels "normal" with no stickyness in the forks or mono. No sign of any thing wrong (fork leaks or the like). The problem I am about to explain has been consistent throughout my ownership.
My problem is washout on the front end during serious cornering. I have been down a few times because of this and it is starting to effect my "trust" in the bike to the point of becoming reluctant to lay it down (get a good corner). Current settings seem to work ok on harder surfaces but in the dry sand it gets real scary! The new rear tire helps alot but it is still not right.
Any insight/suggestions setting this puppy up would be greatly appreciated!
Thanks in advance.
Woodsy :roll:
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You're my size and those front .40 springs are WAY too soft. Drop in a set of .46 and you'll be golden.
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Hey KX500:
Thanks for the FAST reply!
Does it matter that the springs are "new"? Any suggestions on where to find the .46 springs (best prices). Do you know if I replace them by removing the top caps from the forks or do I have to completely breakdown the forks?
Any reason to question the stock mono spring in the same light?
Thanks SOOOOO much!
Woodsy
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I desert race so I opted for a 5.4 instead of the stock 5.6 shock spring.
After unscrewing the caps, push up on the front wheel and the spring along with the caps will come out the top. You still need to unscrew the caps off of the dampening rods (I guess thats what they're called) to be able to get the fork springs out.
If you get stuck stop, post a message and we'll get taken care of :wink:
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Yup, I agree on the springs. Only difference is that I don't go quite as high on the rate, but still agree this fix is the right direction. I purchase all my springs through Race Tech.
Also, you did not say whether the bike is over steering or under steering. I assume that the bike is under steering, which will be helped by the fork springs. However, if you are driving over the top of the berm, that is a different problem.
Rick
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A while back, based in large part to the advice I got here on PitBull, I purchased new springs from Race Tech. I wound up with .48 in front, and 5.5 in the rear, and I weigh 235 lbs. My stock springs were like moosh under me, and I bottomed out over everything. With the new springs, the difference is incredible! My riding instantly got better due in large part to the confidence I gained by having a bike that provided me the proper feedback. Go to the Race Tech website and use their setup program to figure out what spring rates are best for you (based on your riding weight and your riding style). Then, you can either buy from them (about $200 total front/rear) or someplace else you might prefer. Good luck!
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Thanks you guys for all the input! I am going to the Race Tech web page for a look as soon as I am done with this post response.
Rick - thank you for being so inquisitve. The reason that I didnt post whether or not I am having probs with over steering or under steering is that I didnt know how to articulate that (just not that sharp - but I am learning). I am having a problem with over steering. When I come into a berm I find myself going over the top sometimes. It is almost like the bike has to be "forced" to corner and if you do the front end washes out. Any more input would be GREATLY appreciated!
Thanks again to all!
Woodsy
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I had this exact problem..... I weigh 255 - 270 and once i had new springs really improved handling and confidence. Corners much better. I highly reccomend dropping the cash.
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For woods racing and tight technical desert stuff, I drop my forks between 1/2 and 3/4 inches to help get the big KX around the corners. Once you have your new springs (you're gonna love 'em), try a ride with just the spring change, nothing else (a mistake often made is to change more than one thing at a time. If you don't like the changes, you never know which change was bad). Once you put in few miles around your favorite loop, drop your forks and ride the exact same section of trail. You will then be able to evaluate the impact of the 2 different changes over the same terrain. Finally, if you don't like the forks at 1/2 inch above the tripple clamps, try 3/8 inch or 1/4 inch. You will be surprised at how such a little change can effect your ride.
Let us know how things work out.
Rick
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ok then, I want to get this right. What perse' is the effect of lowering the front of the bike via allowing the tubes to slide up inside the triple clamps? Will it quicken the steering at slower speeds but cause some head shake at higher speeds? If the answer is yes, than the basic effect is to actually shorten the wheelbase...does this sound about right?
I ask, because the fork tubes are flush with the top of my triple clamp at this point, and I am wondering if I could be helping the bike to turn better if I drop the front incramentally. Thanks in advance. :D
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ShanMan, you are exactly right on your assumption
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Thanks you guys!
All the advice was/is greatly appreciated! I will keep you all informed as I progress!
Woodsy
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Shanman,
If you raise the forks in the clamp (more tube sticking out above the TC) you 'effectively' quicken the steering by making the head tube closer to vertical. You also chage the weight split - adding more weight to the front. You will need to adjust your rear sag when you raise the fork tubes.
Raising the fork tubes ~12mm made a HUGE difference on my WR400. I raised the forks on my KX ~12mm but it had been so long since I'd ridden the bike I don't have a base line. I just know I didn't have any trouble with the front end not turning.
Brian
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Well gentlemen I had a VERY productive day, thanks in part to all of you!
I took the advice to try some things (good advice to do it one step at a time!!!).
I have not purchased springs. I thought I would try moving my forks up first - mainly cause its free (except fo time).
I started by moving them up to the bottom of the caps - very little change. I moved them up to the second line - WOW!! I spent 4 hours covering everything from tight trail to open/whooped out powerlines (looking for head shake) and it appears that you guys hit the nail on the head! The BIG MEAN GREEN MACHINE no longer feels like a school bus!!
Next move is new springs and resetting of the mono race sag (I think I will try 4 1/2 inches).
Ahhhh, life is great!
Thanks
Woodsy
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Not sure you want to move to 4 1/2 inches on the shock race sag. Several years ago, I started using Daryl at Acme to tune suspension, and have learned a great deal. Here is the process I have used for years:
- set your static sag at one inch (this is the difference between on a stand with no weight on the back tire, and off the stand with the bike weight only.
- Gear up and check the race sag. If you are 3 3/4 to 4 inches, the spring is about right for your weight/riding position. Much more, you need a heavier spring. Much less, you need a lighter spring. This is a general rule only. I have used this process when setting suspension for others, and have found some folks have had to set their static sag to 2 inches to get close to 4 inches. On the flip side, I have found static at 1/2 inch to get to 4 inches. Swap springs, and they ride much better, and with more confidence.
- A little more or less on the static sag can make a big difference. I actually run 1 1/8 static sag and have for years. However, race sag is still just under 4 inches, but I ride way forward on the bike, so my riding position unweights the rear just a bit.
Like most folks on this site at about 210 lbs, I have swapped to a 5.4 rear, and run heavier springs in the front (although I only run .43 springs. For most folks, the heavier springs are going to be the ticket).
If you think about it, by lowering your race sag in the rear, you are giving up some of the effective travel, which may result in more bottoming of the rear shock. Something you might want to consider in your tuning process.
Good luck
Rick
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Rick:
Thanks again for ALL the help! I had the 5 out all day today (included some the of narliest, root infested stuff around). Put another 120 miles on her and only had one slight flaw the whole day. Believe it or not, I actually had an understeer stituation on a real tight bermed corner! It almost felt good (just knowing that it will now understeer!).
I am know going ride it for while (while saving my coins for those new springs).
I left my race sag alone and probably will for the time being. When I set it up (when I first bought it) the stock rear spring came out at just under 4" with 1" static. I have now got 4 and 1/16 so it looks pretty good! Setting the sag on this bike is easy to get at (I have been removing the sub frame/air box - is that how you do yours?) but kind of a hassle to do alone - like I always end up doing :) I will probably follow your advice and leave it where its at!
Anyway, thanks again!
Scott
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Have you thought of trying Pro Circuit pull rods?They keep straight line stability,but quicken the steering.
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On the pull rods, I have thought of using them in the past, but never wanted to lay down the coin. I know Destry uses them, and I talked with him a little about the attributes. I will probably install a set at some point.
On the rear sag adjustment, the correct method is to remove the rear sub frame and use the special wrenches to turn the sring adjustment nuts. Too much work, and I want to get on the trail. I switched to using a long punch, on which I ground an angle to better bite the tabs on the nuts. It works much better than the ol' screw driver, as the flat surface ground to an angle does not mangle the tabs. I also use a black permenant marker to mark one of the tabs before I start any adjustments. I note the position of the marked tab, and can then count the rotations. If I adjust too much, I know how many turns I adjusted, and can adjust the opposite direction about 1/2 way. If I adjusted backwards too much, I split the amount in half again, and adjust in the original direction. With this method, it is easy to dial in your spring because you always know how many rotations (or partial rotations) have been taken. After the initial adjustment, it is simply backwards or forwards in smaller and smaller increments until you achieve the desired sag.
Have fun.
Rick
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On my WR400 I can turn the entire spring to adjust preload. Just use a punch to loosen the locking ring (upper one) and back it off, then turn the spring and the adjuster nut comes along for the ride. Haven't tried this on the KX yet.
Brian
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Turning the spring is exactly how I did it on my KX5...FYI. :D
<edit> subframe off BTW.
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Hey, never tried to turn the spring with the shock on the bike, but what a great idea. This is the method I use when servicing the shock off the bike, so why not on the bike? The only problem is that I have big hands, so not sure I can get my hands around the spring without taking off the sub frame. Next time I adjust the spring, this will be the first thing I try...
Thanks
Rick
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I have been loosening the top spanner nut and turning the spring on mine. This does work REAL well and saves on chewing up the spanner nuts. I doent see how it will be possible to do it without removing the subframe though - I am going to take a look at grinding a chisle to match the angle of the spanner surface for those "quicker" adjustments!
Scott
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Woodsy,
I have to agree with the others. Mine responded to fork lowered at least 1/2" in the clamps (no head shake ever) and some .43 springs (i'm 210lbs) and drop the oil level to 125mm. It also really likes the dunlop 955F tire or probably any with prominent side knobs. Seems to plane nice when pushed too far without washing out.