2005 YZ250 Set up and tuning

[Victorylap]

I am working on setting up my new 2005 YZ250. I have had it for a couple weeks and have ridden it 4 times on the Hangtown National track for practice days and once at Club Moto a nearby track.

I am having some difficulties in getting it to work right.

Frist off I weigh 190#s probaly about 200# in gear. I am a A level offroad rider competing in local and national Hare Scrambles, WORCS, ISDE, and SCORE Baja 1000 & 500.
I am probaly about an intermediate level mx'er. I have never been too good at diagnosing a suspension problem or dialing in my bike by myself but I usually get it set up pretty good with the right help.

I realize the stock springs are probaly a bit light for me but I have got the race sag set correctly at 100mm with 30mm of static sag.

The bike came set up very stiff and is causing me blisters. I have tried backing out the low speed compression on the front forks and shock and taken about 1/3 turn out of the high speed adjustment on the shock. I have set the rebound two clicks slower (in) on the shock rebound and 4 clicks slower on the front forks.

The bike fells quite unstable on high speed rutted, choppy down hills with a tendency to headshake going into braking bumps. Steering is good if pushed hard but will at times slde in the front end. Traction in slick and hardpack corners is unpredictable to the point where I am not sure if the rear or front tire could come loose.

I have had a few scary moments in whoop sections at fast speed when the rear end started swapping almost lock to lock.

Over jumps the suspension is mostly pretty good except for the occasional overjump or short landing when the forks can bottom.

I am considering adding a bit more fork oil to try to keep the forks up a bit higher. I have also considered adding a bit of compression to the forks but the ride is pretty rough and I need to be able to hold on to this VERY FAST beast.

I want to get a decent baseline before I start to make any modifications to the springs or valving. I would greatly apreciate any guidance.

What testing has anyone done and what settings are working for you?

Thanks,

 

[Radiator Ron]

wondering if you could tell me what the primary gear reduction, and first through 5th gear ratios are? It will be listed in the specs of your manual. Seems like your cranking in rebound alot, i try to run rebound as fast as i can without the bike thowing me up on landings, or rebounding too fast in corners. Heres some things dirt rider said about it. The front bottomed, they added 7ccs oil that eliminated bottoming, they were able to back out on compression to be plusher. This may help your head shake. They did'nt fiddle with fork rebound at all.
They did'nt change shock at all, but said sag was important. Since your headshaking I'd try 106mm sag, which can also help with swapping.

 

[marcusgunby]

Also so far it seems the 250s are setup harsh and its lookign like valving is needed to get them working right, the 125 seems to be getting better feedback and needs less work-i wouldnt worry about the springs for now as the inner chamber spring adds slightly to the overall rate.I think your going to have to get the valving sorted.

 

[steve125]

Before getting them re-valved, try adding 8cc of oil to the outer chambers. This will allow you to back out the compression clickers(start back at stock), the forks will be plusher and have less dive and bottoming. This worked real well on the 05 YZ 125 :cool:

 

[dbrace]

The 2005 frame is part of the problem. It delivers a very predictable but harsh ride which makes suspension setup even more critical.
As is normal for the 250 yz, the suspension is harsh over the small stuff but still prone to bottoming.
Give the suspension a good (4/5 rides)amount of time to settle in and then re-evaluate your springs.

As allways it can be made better to suit your needs.

www.dbracesuspension.com.au

 

[426 Pilot]

Turn out rebound. Your suspension is packing.

 

[Victorylap]

Thanks for the feedback.
Sorry Ron I havnt checked the gear ratios.

I will try adding some oil to the Forks.

426 pilot, I have been both ways with my rebound but havnt yet found my happy medium.

I was really hoping for some of you expert tuners out there to give me some feedback on your experience with this new machine. I have read the mags and will try their suggestions but I would really like some profesional feedback from someone doing testing. I will be glad to give you my feedback on how your setup is working. When I feel I have made the best atempt at getting the bike close I may be looking at doing some valving modifications. First I want to see how close I can get with proper oil height, clicker adjustments, sag settings and maybe spring rate experimentation.

Tanks for any help.
Darrick Merrill
2002 ISDE Bronze
2002 Baja 1000 Sportsman Champoin
2003 WORCS 4th ranked Semi Pro
2004 Baja 500 4th open pro mc

 

[dcwilson]

wondering if you could tell me what the primary gear reduction, and first through 5th gear ratios are? It will be listed in the specs of your manual. Seems like your cranking in rebound alot, i try to run rebound as fast as i can without the bike thowing me up on landings, or rebounding too fast in corners. Heres some things dirt rider said about it. The front bottomed, they added 7ccs oil that eliminated bottoming, they were able to back out on compression to be plusher. This may help your head shake. They did'nt fiddle with fork rebound at all.
They did'nt change shock at all, but said sag was important. Since your headshaking I'd try 106mm sag, which can also help with swapping.

Gear ratios are the same as 2004...yamaha.com

 

[E-WA]

I too am having trouble with this bike set up. The front end feels like it is on a caster, no confidence at all in the way the bike handles.

 

[russ17]

Guy's ,
My opinion on the 05 fork is that it has a extremly fast reb circuit. It seem's in stock form, is only for the very fast at heart. I have herd of guy's that love it and others that can't stand it.
I hated mine at first, but love it now.
It can be made into a awsome fork. IMO
As dbrace has mentioned allow it to break in


Russ

 

[i_955]

You are to heavy for the stock rear spring.

All the attemps and time you are making are in vain. As you get happy or comfortable with a setup the rear spring will settle and you will always be fiddling with your settings. There will be no correct ballance until you match the springs to your weight.

I love the 2005 but can only afford a 2002. I'll pick up a 05 next year.
Regards....

 

[dcwilson]

I too am having trouble with this bike set up. The front end feels like it is on a caster, no confidence at all in the way the bike handles.

I raised the forks about 5mm, backed out the compression 6 clicks from stock and two clicks IN on the rebound...almost there. I think another click or two in on the rebound and I will be dialed on the forks. Shock is good to go stock settings.

oh, BTW I race desert, not MX. As Russ said the rebound is too fast at stock settings.

 

[arnold]

any updates with the 05 yz250 suspension tuning?

I have had mine a few months it is broken in, but the front fork just won't work as good as the CR's do, anyone had anyluck? I weigh 210, and just play ride it (for now) in the Bay Area. Lets keep this thread going!

 

[dcwilson]

At 210 you will need to respring the front and back, even for play riding. What are the forks doing or not doning that you would like to change. Mine are working pretty good, 6 clicks out on the compresion and 1 in on the rebound from stock. I weigh 190 using satock springs. It does bottom when I flat land a jump, but that does not happen much in a desert race.

 

[yam 3]

I installed some gold valves in my front forks and followed the instructions for the proper shim stacks. So far the front end feels much more stable now, but i think that I'll have to slow the rebound down as it feels a little "springy". Worthwhile imo. One thing to note the bike had about 15 hrs on it and the fork oil was REALLY dirty.

 

[arnold]

05 yz250

It is rough on bumps and whoops, and it does not corner as well as a 04 cr250, I have mainly riden it with 2 clicks in on the rebound like my friends cr, i also tried two clicks out out on the compression and it was a little softer. The yz does seem to jump staighter than the cr though, I am going to try pro taper bars and a diifferent clamp because the stock bars seem a little low. Aftershocks a reputable company here said they would re valve the bike(and make a new peice for it?) for $500 but said the stock springs are fine for me? I want to have it done properly so I want some advice. Its not bad but I just want it better.

 

[dcwilson]

It is rough on bumps and whoops, and it does not corner as well as a 04 cr250, I have mainly riden it with 2 clicks in on the rebound like my friends cr, i also tried two clicks out out on the compression and it was a little softer. The yz does seem to jump staighter than the cr though, I am going to try pro taper bars and a diifferent clamp because the stock bars seem a little low. Aftershocks a reputable company here said they would re valve the bike(and make a new peice for it?) for $500 but said the stock springs are fine for me? I want to have it done properly so I want some advice. Its not bad but I just want it better.

If you are going to stick with the stock rear spring, set the sag as close as you can, I doubt you will get it right on 4" and still have an inch of free sag, so you are going to be a little low in the back. To compensate for that you will need to lower the front by raising the forks in the clamps. I just barely got the sag close at 190lbs. Also the rebound on the forks is too fast stock, these two things combined make it hard to turn, ie front end washing out. Slowing down the rebound (more rebound dampening) helps keep the front from washing out. But get the sag right first. My final settings are 6 out on the compression (I might go even more), 2 in on the rebound (from stock settings), forks raised about 5mm, shock is good stock.

My 01 CR handled great, but the YZ can be tuned to match. Save your five hunny.

 

[J.Gordon]

Here my settings for woods riding. 220 lbs
Front Spring : Stock
Rear Spring : 5.2
Fork Settings
17out on compression
16 in on Rebound
Forks raised up barely past the line.

 

[steve125]

My settings sound real close to dcwilson. Anyone riding MX and 190lbs plus needs the next step up stiffer springs.
I've re-valved the rear shock and so far I'm happy with it.

Still working on the forks, I feel they have good action, but bottom to easily. Im going to continue to add oil to the outer chamber until they are firm enough, and then start backing out the compression adjuster. Right now I'm 6 out on compression and its a bit to harsh. My rebound has been at 10 out for quite some time and works well.

The number 1 thing you can do to make that 05 250YZ carve the turns is to raise the forks up in the clamps. 5 mm is a good start. Of course the rear shock needs to be balanced with the proper spring and sag settings. I run 100mm sag, with a 25mm free sag and a 5.1 rear spring. The forks are also 1 rate up from stock.

 

[bikedude127]

Hey all, I admit. Im a newbie here :)

Im also having this dreaded head shake problem. Ive tried clicks in several different places and am having little luck. Ive got my sag very close and have added five cc to front fork, I think I may need more. Ive tried speeding up the R and softer on the C in the front with very little luck. Any suggestions?

A little info.
150lbs and riding ex. off-road and int. MX.
The rear feels good but the front realy seems to be riding low in the stroke and using all the travel but still feels quite harsh. From what Ive been hearing and reading, it seems that a re-valve is in the future.

Thanx for your help

 

[steve125]

Try 7 out on compression and 10 on rebound. I havent had any headshake with that setting, another 5cc of oil would be a good idea also.

 

[dcwilson]

Hey all, I admit. Im a newbie here :)

Im also having this dreaded head shake problem. Ive tried clicks in several different places and am having little luck. Ive got my sag very close and have added five cc to front fork, I think I may need more. Ive tried speeding up the R and softer on the C in the front with very little luck. Any suggestions?

A little info.
150lbs and riding ex. off-road and int. MX.
The rear feels good but the front realy seems to be riding low in the stroke and using all the travel but still feels quite harsh. From what Ive been hearing and reading, it seems that a re-valve is in the future.

Thanx for your help

That's all not adding up. At your weight the fork springs should be plenty to keep the front end up. I bet you aren't getting the right sag. 4 inches with you on the bike, and 1 inch with you off. I bet you are riding too high in the rear and that is where your headshake is coming from. If you are sure you got the sag right you can lower the forks in the triple clamps and make the front a little higher. Clicks won't get rid of headshake.

 

[bikedude127]

That's all not adding up. At your weight the fork springs should be plenty to keep the front end up. I bet you aren't getting the right sag. 4 inches with you on the bike, and 1 inch with you off. I bet you are riding too high in the rear and that is where your headshake is coming from. If you are sure you got the sag right you can lower the forks in the triple clamps and make the front a little higher. Clicks won't get rid of headshake.

Hows is goin.

I assure you Im using all the travel and I havent been ridden MX, I was doing my testing on race day at a GP race. The forks are at the caps in the triple clamps already.. Should I go down further.? I think I was about 10 out or so on C in front, (trying to eliminate the harshness) and am wondering if that was my problem. Ive also heard that if you're too soft on C, that will cause you to ride low in the stroke and that the harshness actually comes from being in the midstroke too much.
I have the sag very close, but I checked Race Tech spring calculator and they called for a 4.7 for my weight. I KNOW that would be too soft. Called for a .407 or .410 for the front which Im sure that would make my problem worse, right?
(stk .440 front, 4.9 rear) Thanx for your help :cool:

 

[steve125]

Hows is goin.
Ive also heard that if you're too soft on C, that will cause you to ride low in the stroke and that the harshness actually comes from being in the midstroke too much.

:

You got that right :nod:

 

[lemons r yellow]

Here is most of your problems with the forks on the new yamy.
The stock fork springs are too short and the fork has no preload.
You need to cut some 7mm spacers out of 1.25 in pvc and install them above the top spring spacer.
The oil is also crap and the fork holds very little oil in the outer chambers. I have also found some cases where the inner chambers were not bled properly.
Worst come to worst add the spacer to give the fork some preload.
Then use 220cc of of 7.5weight fluid in the outer chamber only and you should see feel a better fork