Twitchy front end solutions

jamiechapman418
Any suggestions for a twitchy feeling front end? Sag is set at 105mm. Fork 5mm up from stock. 12 psi front and rear. New steering stem bearing and have tightened head tube. Front wheel seem to really dance around at moderate speed. Low speed feels ok and high speed doesn’t seem to bad either.
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AJ565
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AJ565 6/8/2021 8:00pm
6/8/2021 8:00pm
Simple, just go high speed or low speed. You’re either first of last, shake and bake.
jamiechapman418 6/8/2021 8:25pm
6/8/2021 8:25pm
Solid advice haha. I guess more I think about it it’s low to moderate speed. High speed feels ok
murph783
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murph783 6/8/2021 9:01pm
6/8/2021 9:01pm
What bike?
kieran_macca 6/9/2021 12:41am
6/9/2021 12:41am
Try a few clicks stiffer on compression on the forks, you might be riding too low in the stroke. i.e. suspension too soft.

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wrc777
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wrc777 6/9/2021 5:03am
6/9/2021 5:03am
What tires? How many hours on them? 12 psi seems a little low for most tires.
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jamiechapman418 6/9/2021 5:22am
6/9/2021 5:22am
This is on a 2019 rmz 250. 9 hours on tires. Mx33s. I did try to go a few clicks stiffer on fork compression and the difference in handling was minimal, maybe placebo. But the front end felt then felt pretty rigid and braking bumps and jump landings were pretty harsh.
seth505
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seth505 6/9/2021 6:37am
6/9/2021 6:37am
Are you saying your forks are set 5mm higher in the clamps than stock? If so, I'd leave your rear sag but try setting the fork height back to stock (2.5mm above clamps) as a test.
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wrc777
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wrc777 6/9/2021 7:10am
6/9/2021 7:10am
jamiechapman418 wrote:
This is on a 2019 rmz 250. 9 hours on tires. Mx33s. I did try to go a few clicks stiffer on fork compression and the...
This is on a 2019 rmz 250. 9 hours on tires. Mx33s. I did try to go a few clicks stiffer on fork compression and the difference in handling was minimal, maybe placebo. But the front end felt then felt pretty rigid and braking bumps and jump landings were pretty harsh.
Try a little higher tire pressure. 0.5-1 psi. It is free and it may help.
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kb228
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kb228 6/9/2021 7:49am
6/9/2021 7:49am
Raising the forks makes a more twitchy front end. Try running the fork cap flush with the top clamp. It will make the bike sit more like a chopper.
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murph783
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murph783 6/9/2021 9:37am
6/9/2021 9:37am
If it was me, I’d try 110mm of sag. That didn’t work, move the forks back down 5mm. I also run 33’s at 13.5 psi for what it’s worth so maybe monkey with the pressures a bit. I find they like a little more. I mean failing all that there’s geometry changes you could make-clamp offset or a lowering link, but I would say you shouldn’t need all that just yet.
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murph783
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murph783 6/9/2021 9:38am
6/9/2021 9:38am
murph783 wrote:
If it was me, I’d try 110mm of sag. That didn’t work, move the forks back down 5mm. I also run 33’s at 13.5 psi for...
If it was me, I’d try 110mm of sag. That didn’t work, move the forks back down 5mm. I also run 33’s at 13.5 psi for what it’s worth so maybe monkey with the pressures a bit. I find they like a little more. I mean failing all that there’s geometry changes you could make-clamp offset or a lowering link, but I would say you shouldn’t need all that just yet.
Also don’t do all that shit at once necessarily, try em one at a time and in different combinations so you know what’s doing what
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jamiechapman418 6/9/2021 10:40am
6/9/2021 10:40am
murph783 wrote:
Also don’t do all that shit at once necessarily, try em one at a time and in different combinations so you know what’s doing what
Yup got it. I think I will start with sag and then the fork height.
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Rotaholic
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Rotaholic 6/9/2021 2:48pm
6/9/2021 2:48pm
Lowering link and run the wheel as far back as you can, might need a new chain.
jamiechapman418 6/9/2021 6:51pm
6/9/2021 6:51pm
Have thought about a link but I just put on a new chain. .8 hours on it. I put the forks back to 2.5mm height and that didn’t seem to alleviate it. Messed with air pressure a bit but going higher I think made it feel even more nervous. My track is very hard pack right now so I’m not sure if that’s the issue? Will try 110 mm sag tomorrow. Will that mess with my shock compression and rebounding at all if I run more sag?
murph783
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murph783 6/9/2021 8:22pm
6/9/2021 8:22pm
Nope, sag is a separate measurement from the compression and rebound. But really you should have the sag dialed before you start playing with clickers.
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garasaki
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garasaki 6/10/2021 5:49am
6/10/2021 5:49am Edited Date/Time 6/10/2021 5:50am
Could be shock settings maybe?

I ride extremely hard pack tracks as well.

I found it was really beneficial last year to actually set aside time to dial clickers in. I went out twice (once front end, once rear end), just brought a screwdriver and 17mm socket (for shock compression) and rode 2 laps, changed a clicker, rode 2 laps, etc. Made notes and wrote down the usable range of the clickers and developed a baseline setting.

From there, playing with sag and fork height might be the next step. (As mentioned above, sag is important to get close early on in the process - but this is an iterative process.)

WRITE EVERYTHING DOWN!!! The great part about all these adjustments is: they are free. Just be organized about how you do it, change one thing at a time, and write it down!!

Last thing - I had some real nasty headshake following a fork rebuild once, tried a ton of different things - then went to adjust my rebound and realized I had my left and right rebounds set about 8 clicks apart. So you may want to just see where your clickers are right now and make sure there isn't something that is WAY out of wack.
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kb228
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kb228 6/10/2021 7:01am
6/10/2021 7:01am
The stock 2.5 might be too high. More sag and lower forks means less front end twitch. Another thing to consider is reducing compression damping. Too much it will deflect off bumps.
Paw Paw 271
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Paw Paw 271 6/10/2021 11:41am
6/10/2021 11:41am
The sag does effect the clicker setting as you are starting the stroke in a different starting point. Set sag then deal with clickers. If no go, change sag and reset the clickers. Do this until you find the sewwt spot. Tire ais press ure make a big difference with track hardness. The harder the track, the higher tire pressure will be needed to keep the tire knobs front folding over in the turns.
Soft track try 13-14 psi.
Medium track try 14- 15 psi.
Very hard pack try 16- 18 psi.
I have run as high as 21 psi to find the sweet spot on hard track. This makes the front feel a bit loose, but you will find that it is really holding better after riding it for a bit.
Remember to reduce compression as you go up on tire pressure and increase the rebound damping at the same time.

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GetItOnLikeTron 6/10/2021 12:22pm
6/10/2021 12:22pm
To help reduce headshake move your weight forward and some times the forks have to much rebound.
jamiechapman418 6/10/2021 2:29pm
6/10/2021 2:29pm
Thanks for the input everyone. Hopefully tonight I can test again. Gonna try and lower my fork compression and try. Then give the tires a try at that 16 psi area.
AJ565
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AJ565 6/10/2021 2:34pm
6/10/2021 2:34pm
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass is toast and you should replace the tires. That can cause the feeling you’re taking about too.
wrc777
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wrc777 6/10/2021 3:51pm
6/10/2021 3:51pm
I would try 14 psi before 16. 16 is pretty high.
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kb228
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kb228 6/10/2021 4:35pm
6/10/2021 4:35pm
AJ565 wrote:
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass...
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass is toast and you should replace the tires. That can cause the feeling you’re taking about too.
9 hours???
CKNY
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CKNY 6/10/2021 4:41pm
6/10/2021 4:41pm
AJ565 wrote:
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass...
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass is toast and you should replace the tires. That can cause the feeling you’re taking about too.
Yeah no way. Maybe if you ran it flat for 12 hours.
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jamiechapman418 6/10/2021 6:59pm
6/10/2021 6:59pm
So I tried tires at 14 and it did seem like I had more front end bite in corners but didn’t really change the straight line nervous feeling. I dropped the compression on the forks 2 clicks and found out I’m at the end of my clickers. It was maybe marginally better. Pushing on my forks though I don’t think theres anyway I’m too low in the stroke. They are pretty firm. Maybe I need to try a lower spring rate?
AJ565
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AJ565 6/10/2021 7:25pm
6/10/2021 7:25pm
AJ565 wrote:
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass...
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass is toast and you should replace the tires. That can cause the feeling you’re taking about too.
CKNY wrote:
Yeah no way. Maybe if you ran it flat for 12 hours.
Don’t be so sure. The MX33 breaks down fairly fast and you start to lose side bite. The Hoosiers are the worst with how fast they break down and the Pirelli seemed to last the longest.
garagedog 6/10/2021 9:20pm
6/10/2021 9:20pm
jamiechapman418 wrote:
So I tried tires at 14 and it did seem like I had more front end bite in corners but didn’t really change the straight line...
So I tried tires at 14 and it did seem like I had more front end bite in corners but didn’t really change the straight line nervous feeling. I dropped the compression on the forks 2 clicks and found out I’m at the end of my clickers. It was maybe marginally better. Pushing on my forks though I don’t think theres anyway I’m too low in the stroke. They are pretty firm. Maybe I need to try a lower spring rate?
Stock forks? Didn't those have crazy stiff springs and valving?
I have a 2020 and it was way off. Unless you weigh 250lbs.

28hall
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28hall 6/11/2021 1:55am
6/11/2021 1:55am
How much do you weigh? Clickers aren’t going to help of the spring is too stiff for you
CKNY
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CKNY 6/11/2021 3:53am
6/11/2021 3:53am
AJ565 wrote:
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass...
Something I thought about is if you’re running 12 psi in your tires and you have 9 hours on them than chances are that tire carcass is toast and you should replace the tires. That can cause the feeling you’re taking about too.
CKNY wrote:
Yeah no way. Maybe if you ran it flat for 12 hours.
AJ565 wrote:
Don’t be so sure. The MX33 breaks down fairly fast and you start to lose side bite. The Hoosiers are the worst with how fast they...
Don’t be so sure. The MX33 breaks down fairly fast and you start to lose side bite. The Hoosiers are the worst with how fast they break down and the Pirelli seemed to last the longest.
I agree the Hoosiers are the worst but even the Dunlop’s at 12 vs 14 are not roaching carcasses that fast for the average rider on this board. Maybe a very fast pro…
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jamiechapman418 6/11/2021 6:52am
6/11/2021 6:52am
Ya I am no where in the realm of pro. I'm 33 and upper end of C class on a good day. I don't race but maybe once a year anymore and ride strictly for the fun of it. With full gear on I am at 205 lbs. Race Tech calls for .46 springs and stock is .50. Maybe that's where I need to head.

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