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Suspension Setting Issues

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Ok, I had noticed some harshness in my suspension after about 4 hours of riding my new 08 YZ250F. After doing some research, I decided to change the fork oil. I used Yamaha 01 Suspension oil in the inner cartridge, and Belray 5wt in the outer cartridge, 350cc's of oil in the outer chamber. After going out for a ride, I noticed the suspension was kicking coming into corners with breaking bumps, and had head shake when in 3rd gear or higher speeds. My first adjustment was two clicks in on the fork rebound. Which seemed to help quite a bit. It seemed to settle the forks down coming into corners, and almost completely alleviated the head shake. I then decided to turn in the rebound on the shock 3 clicks. This bike is super stable at speed, and the suspension works very well on 4th/5th grear staights, but is still a little harsh in the 2nd/3rd gear sections. I dont know if it was all in my head that the suspension on this bike was super plush when I first got it, since I was coming off a KTM 250sx. I am thinking about taking some oil out of the forks, maybe about 10cc out of each fork leg. Maybe this will take some of the harshness away. I guess my biggest problem is that I dont know what changed between the first few hours of riding this bike, and now. I have about 10 hours on the bike now.

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there are two things here you need to look at, firstly bleeding the fork inner cartridges, kyb's are hard to bleed, you have to be patient and to some extent follow some procedure. air in these makes them real harsh.

the second is to make sure the forks arn't bound up on the axle.

there are various procedures on here to help you out with fork installation. you wouldnt believe how many forks i find incorrectly fitted.

as for your settings, usually to hard and too slow a fork will cause headshake, and make the fork harsh, other issues like rear wheel not straight, too little sag to much fork preload all can cause this.

check your sag is 100-104mm, free sag 25-30mm

forks are not bound up,

ensure you have the correct springs for your weight!

fork clamp bolts not over tightened, 12-14nm lower 17nm upper clamp

back out the reb on the bottom of the forks, and the comp around 3-4 clicks,

also drop the forks nearly flush with the top clamp.

to give you some base settings for the 08 250f.

shock:

high speed comp- 2turns out

low speed comp - 10 out

rebound - 13 out

forks:

spring preload - 4mm

comp - 11

rebound - 14

these are guidlines but should be a good starting point.

mark.:)

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there are two things here you need to look at, firstly bleeding the fork inner cartridges, kyb's are hard to bleed, you have to be patient and to some extent follow some procedure. air in these makes them real harsh.

the second is to make sure the forks arn't bound up on the axle.

there are various procedures on here to help you out with fork installation. you wouldnt believe how many forks i find incorrectly fitted.

as for your settings, usually to hard and too slow a fork will cause headshake, and make the fork harsh, other issues like rear wheel not straight, too little sag to much fork preload all can cause this.

check your sag is 100-104mm, free sag 25-30mm

forks are not bound up,

ensure you have the correct springs for your weight!

fork clamp bolts not over tightened, 12-14nm lower 17nm upper clamp

back out the reb on the bottom of the forks, and the comp around 3-4 clicks,

also drop the forks nearly flush with the top clamp.

to give you some base settings for the 08 250f.

shock:

high speed comp- 2turns out

low speed comp - 10 out

rebound - 13 out

forks:

spring preload - 4mm

comp - 11

rebound - 14

these are guidlines but should be a good starting point.

mark.:)

hey mark can u give me some base settings for a 2003 rm250?

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Ok, I will start with these settings tommarow and see what it feels like. Its a pretty drastic diffeance from the stock settings, but that might be exactly what I need. The high speed compression on the shock was only at 1.5 turns out. Pretty much all the compression settings were stiffer than what you suggested, and the rebound was all set stiffer. Its definately a differant direction than I was going with the settings, but it could very well work out perfectly.

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hey mark can u give me some base settings for a 2003 rm250?

sorry - i have no test data on the 03 rm, but if its not doing somethin your happy with pm me and we'll find a soloution.

mark.

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there are two things here you need to look at, firstly bleeding the fork inner cartridges, kyb's are hard to bleed, you have to be patient and to some extent follow some procedure. air in these makes them real harsh.

the second is to make sure the forks arn't bound up on the axle.

there are various procedures on here to help you out with fork installation. you wouldnt believe how many forks i find incorrectly fitted.

as for your settings, usually to hard and too slow a fork will cause headshake, and make the fork harsh, other issues like rear wheel not straight, too little sag to much fork preload all can cause this.

check your sag is 100-104mm, free sag 25-30mm

forks are not bound up,

ensure you have the correct springs for your weight!

fork clamp bolts not over tightened, 12-14nm lower 17nm upper clamp

back out the reb on the bottom of the forks, and the comp around 3-4 clicks,

also drop the forks nearly flush with the top clamp.

to give you some base settings for the 08 250f.

shock:

high speed comp- 2turns out

low speed comp - 10 out

rebound - 13 out

forks:

spring preload - 4mm

comp - 11

rebound - 14

these are guidlines but should be a good starting point.

mark.👍

Just out of curiosity, how did you come up with these settings? Were they popular with some riders or something?

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through exstensive testing.

On the stock setup-ie valving and oil heights etc. we test the clickers and sag etc to death to come up with the best it will be so we can acurately measure our modifications against a weel set up stock machine. the stock valving on these bikes are pretty good, although with modifications as well as valving they can be made a heap better - there the plushest setup on the market and very good when done right. but its a lot of hours testing.👍

there is no ideal setting to suit everyone, and these may not be perfect , but should be a good base to dial yours in.

just dont forget to make changes 1 or two clicks at a time and ALWAYS do the rebound first, as this has affects on compression damping.

mark:thumbsup:

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through exstensive testing.

On the stock setup-ie valving and oil heights etc. we test the clickers and sag etc to death to come up with the best it will be so we can acurately measure our modifications against a weel set up stock machine. the stock valving on these bikes are pretty good, although with modifications as well as valving they can be made a heap better - there the plushest setup on the market and very good when done right. but its a lot of hours testing.👍

there is no ideal setting to suit everyone, and these may not be perfect , but should be a good base to dial yours in.

just dont forget to make changes 1 or two clicks at a time and ALWAYS do the rebound first, as this has affects on compression damping.

mark:thumbsup:

Well I am really glad you shared those settings with me, because they feel great. The forks feel great, but I think a big part of that is because the rear suspension is working so much better. I am going to be doing DaveJ's oil and mid valve mods after this riding season is over for me, but for now these settings work great. Thanks again.

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i have a 04 crf450 which is primarily desert ridden, its time for fork seals again and i was inquiring about valving. @ 175# springs should be ok (i,m told) but what might i expect from diff valving and what is involved? ive been quoted several prices and also been told this bike needs no changes for what i do. i have no complaints - the bike rips and gobbles up everything great when set up right - i have too much oil from my replacement of fork seals a couple of years ago but did not know if i was missing anything by not having a custom setuo. any advice? thanks

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Well I am really glad you shared those settings with me, because they feel great. The forks feel great, but I think a big part of that is because the rear suspension is working so much better. I am going to be doing DaveJ's oil and mid valve mods after this riding season is over for me, but for now these settings work great. Thanks again.

thats great:thumbsup:

you will be inpressed with dave's product. i use his oil in EVERY set of modified forks and shock i do now. its top notch 👍

Glad i could have helped.

mark.

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if you say the bike feels good, why change it. i only suggest modifications if you cant get a good set-up for yourself with stock stuff.

sometimes the stock stuff just works good for certain people.

if it aint broke dont fix it.

but if your gonna do the seals, again some of the smart performance 215.VM2.K5 may be a good benefit for you.

mark.

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Is that sag figure (25-30mm) measured when the shock is cold? Does the sag figure change when the shock is hot? Will it reduce as the shock heats up ?

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if you say the bike feels good, why change it. i only suggest modifications if you cant get a good set-up for yourself with stock stuff.

sometimes the stock stuff just works good for certain people.

if it aint broke dont fix it.

but if your gonna do the seals, again some of the smart performance 215.VM2.K5 may be a good benefit for you.

mark.

Because you only know the best you have ridden, and I am coming off a KTM 250SX with so so suspension. I am not messing with it until the winter time, and I can always change it back if I dont like it. The suspension works really well right now, but there is still room for improvement. Thanks again for the settings.

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Is that sag figure (25-30mm) measured when the shock is cold? Does the sag figure change when the shock is hot? Will it reduce as the shock heats up ?

yeah - but its fractional. and yes its at cold temps.

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