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16 250fx spring rates

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I recently bought this 16 250fx with 18 hrs on it . Im coming from ktms and a husky before this and really wish i had just bought one of these to begin with.   I have put about 10 hours on it and iim trying to set it up for the fall hare scramble series near me. I have most everything the way i like it except the suspension.  I dont really understand what yamaha was trying to dk on the spring rates. The front is the same as wr and rear is a rate stiffer? That is certainly not how it feels. I am 6'1" and 190 pounds and the front seems kinda harsh on the little stuff and deflects a little but not real bad. Overall the rear seems okay. The only negative i get from the rear at times is a bouncing on small braking bumps and acceleration chop it seems to just be hitting on the tops. When it bounces though it is usually both ends. My sag is aprox 105 and 30static h.s.is 2 turns out comp at 14 out and reb 8 .  Front is 3mm above clamp and comp 15 reb 8.  

     I have checked the race tech site and it says to go softer on rear and stiffer in rear ??  Seems to me it needs to have both ends a rate softer. I know a lot  of people figure if its harsh it needs stiffer springs but i feel with the bouncing it may need to go softer? Could be wrong and probably are but this why im asking?  Also what does the pressure spring affect in the stroke? Im guessing it is the intial part of stroke and maybe thats all i need is a rate softer on it to calm it down on some of those little bumps and rocks etc.    So basically wondering where i should start? Softer springs in front or softer at both ends?     

       

 

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Can't imagine a .42 in the front.  That is stock 125 spring rate and that bike is 50 pounds lighter than the FX.  I don't have and FX so I won't recommend a spring but I know on my YZ's I ran .46s on 250s and .48 on 450s when I was about 200#.  I have put on some weight so I have had to go up another rate.

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I see your point that would be very light in front.  Thanks  how about the pressure spring?

 

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I would try backing the rebound out on the shock. 8 seems too tight. The rebound adjuster is 6 clicks per turn instead of 4. I am running around 13-15 out on mine.

It will probably help the fork feeling as well.

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Taylor10 - I have the same bike as you, and I have a suspension business.  On my spring tester, the stock springs measured .43 kg/mm in the front and 5.7 kg/mm in the rear.  I weigh 155 and ride at the A level on our local cross country circuit.  For me, the stock fork springs were fine and the stock rear spring was a little stiff to get perfect sag numbers, but I kept the stock spring any way.  

If you came in my shop, I'd probably go with .46 front and a 5.9 rear to suit your weight, but that deflection that you are feeling is valving-related - pure and simple. The stock high speed valving is harsh for trail hack.  Find a good local suspension shop and get that fixed.  Also, while they are inside the shock, have them install lowering spacers.  I'd recommend .20" of spacers.  This will help with the tall rear end and eliminate the stink bug feel by getting the chassis in balance.

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 Also, while they are inside the shock, have them install lowering spacers.  I'd recommend .20" of spacers.  This will help with the tall rear end and eliminate the stink bug feel by getting the chassis in balance.


Isn't that a pretty substantial drop? My research showed most guys (and tuners) suggest a 2-3mm spacer for a 7-10mm drop. With your 5mm spacer, wouldn't that be in the 12-15mm drop range?
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Another thing worth mentioning is, if you're too light on spring rate then your suspension is riding down in the harsher part of the stroke, so it's going to feel stiff. Plushness in the small choppy stuff comes from the top of the stroke which you're probably never in. 

I'm same weight/height, same bike and run .48 front 5.7 rear. Rear is lowered 8-10mm and forks up 5mm in the clamps. 

Edited by Kosmic
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4 hours ago, Goatse said:

 


Isn't that a pretty substantial drop? My research showed most guys (and tuners) suggest a 2-3mm spacer for a 7-10mm drop. With your 5mm spacer, wouldn't that be in the 12-15mm drop range?

 

The FX shock is 4 mm longer than the YZF, and that bike has a bit of stink bug feel, too.  So, I don't see any logical reason for going less than 4 mm.  I've got lots of happy customers running 5 mm of spacer.

I'm 5'8" tall.  On my personal bike,  I put in 9 mm of spacer in the shock.  Plus, I shortened the forks 1/2".  Now, it corners like it's on rails. 

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Very intetesting stuff. Thank you. I suppose i better start with some stiffer springs since that will be the easiest and cheapest first. Im prepared to get a revalve on this bike because i like it so much. Even without the suspension dialed in just the way i like it it feels so much more planted and stuck to the ground compared tothe 17 250xc i had before this.  

Couple of questions though. If i were to get it re valved to get rid of that high speed little hack trail stuff smoothed out would i lose any of the stability of it now? Or any other aspects of the performance? And will it possibly improve with the right springs and the valving may be fine?   Another question is a scotts stabilizer to help with any ďeflection? I realize it is a band aid solution but if valving is going to compromise what i already have would it not be better?  And what if i change the ics pressure spring? Will it help?        Thanks again for the help

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Have you set  rear sag properly and ridden it? Sounds like classic stink bug stance. 

Try sag at 115mm. 

Also bars in forward most mount. 

Set the clickers to standard and go from there 

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1 hour ago, taylor10 said:

 

Couple of questions though. If i were to get it re valved to get rid of that high speed little hack trail stuff smoothed out would i lose any of the stability of it now? Or any other aspects of the performance? And will it possibly improve with the right springs and the valving may be fine?   Another question is a scotts stabilizer to help with any ďeflection? I realize it is a band aid solution but if valving is going to compromise what i already have would it not be better?  And what if i change the ics pressure spring? Will it help?        Thanks again for the help

No, you will not lose that classic Yamaha stability if you get a proper revalve.  Like you, I came off a KTM.  My last bike was a 2016 250 XCF.  This FX is ten times more stable in rough terrain than the KTM was.  And sure, springs alone will help, even if you don't get a revalve.  But, like the other guys have said, if you don't shorten the shock, you will need to run more sag than normal.  115 mm is a good target.

No, changing the ICS spring will not help.  Leave it alone.  I run a Scott's on my FX.  But, I've been putting Scott's stabilizers on all my bikes since 1995.  It will help calm down the front end.

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)Is getting the dog bone shorter another good way to go?  What is the advantage of getting the shock shortened if running 115 sag accomplishs the same thing. I am probably 105 rear sag. I initially went with 94 or 95 rear sag and yeah it was pretty bad with very heavy steering. Then i added about 10mm more to the rear sag getting it near the 105 im at now. At the 94 95 rear sag i had a lot of bouncing on any braking bumps or chatter bumps or just consecutive bumps etc.. it was a bouncing that seemed to be in rythym with the whole bike in a bouncing sensation. I had that same problem with a husky that had springs i knew were to stiff from the previous owner at 235 pounds. After getting the right springs two rates softer the bouncing was gone thats why i was guessing the springs might be to stiff? I can understand though how to soft of springs can do the same i guess? That is also reason for lower reb setting. Thinking more reb damping would slow it down.

    I will try that for my next ride this weekend though is to set sag at 115 and put clickers back to 11 all the way around. Any idea what the static sag is going to be at 115 rider sag? And also if it matters im at the front in B 40+ in my hare scramble series. Hoping if this bike does as good as im feeling with it so far i will be able to move to A class next year. Thanks again this is a great help

 

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I'm 6'0 190-195lbs a rider, we did 4.8 with 1.7 pressure spring for the front. Forks are set flush with bottom of caps. Rear has a 5.9 and 5mm spacer, sag is 105-106. I'd have to check on clicker settings, protune suspension did the revalve. It works amazing 

IMG_0880.PNG

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On 7/18/2017 at 10:11 PM, taylor10 said:

)Is getting the dog bone shorter another good way to go?  What is the advantage of getting the shock shortened if running 115 sag accomplishs the same thing. Any idea what the static sag is going to be at 115 rider sag? 

 

I'm not a fan of lowering links because I believe the stock linkage ratios are good.  Lowering links change these ratios.  The problem is the shock is too long.  For the price of a lowering link, you can get your shock shortened.  If you don't shorten the shock  and decide to go with 115 mm sag and the proper spring rate, you're going to find that the free sag is excessive.  That makes for a lot of up and down movement as you brake and accelerate.  This is a similar problem that the KTM PDS system has if you don't shorten the shock on those bikes.

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Thanks for advice.  I have been contemplating between getting correct springs probably 46s in front and however the rear plays out along with a scott stabilizer and live with the valving that is not that bad  or get the full re valve with springs and wait on a stabilizer until later hopefully not even needing it?  Wish i had the money for both but not really wating to spend that much at one time anyway. Our fall season starts back up in about six weeks so i need to get going on one way or the other. Kinda leaning towards the full re valve with correct springs

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Interesting. I was about to order some new springs (since I got married and can't seem to get back to race weight), and Race Tech also told me to go with some 44 springs on the front, and a 59 for the rear for my 195lb fat ass.

 

 

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Goatse, .44 fork springs seem a little soft for a guy your size.  Unless you're a sit-down rider that rides way back on the seat, I'd recommend going at least .46 and maybe even .48 if you're an aggressive rider.

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I'm 6ft and 175. The best sag setting I have run on this bike is between 110 and 112 with forks 2 to 4mm above the top clamp. The bike needs a lot of weight over the front to turn. It's not a KTM.

the stock Dunlop AT81 does not help with the deflection issues. The stock suspension is pretty damn good on its own. I do run a Scotts on my bike as I run one on every bike I have owned since 2010. 

Dave at Smart Performance built my new set up and it's the best I have run on any bike so far. Almost no deflection. I ride hardpack, rocks and roots. For the stock suspension to work well you really need to be an aggressive fast rider. 

On July 20, 2017 at 7:38 PM, taylor10 said:

Thanks for advice.  I have been contemplating between getting correct springs probably 46s in front and however the rear plays out along with a scott stabilizer and live with the valving that is not that bad  or get the full re valve with springs and wait on a stabilizer until later hopefully not even needing it?  Wish i had the money for both but not really wating to spend that much at one time anyway. Our fall season starts back up in about six weeks so i need to get going on one way or the other. Kinda leaning towards the full re valve with correct springs

Suspension before damper, no brainer. The FX is super stable. 

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The harsh condition you feel in the forks due to trail hack is because of too stiff ICS springs.  Stock is 2.0 which is too stiff for your weight.  Try 1.6 ICS springs, you won't believe the difference it will make.  I weight 160 and feel 1.4 ICS springs are outstanding for me. 

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