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Twitchy on landings but no headshake?

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I have an 03 CRF450 - 20mm offsets and valved suspension - stock spring rates - intermediate rider - and ride MX only.

When I land from jumps the bars twitch. Other than that the handling is good.

This past weekend while working up the guts to clear a 75' tabletop the bike twitched lock to lock three times on the landing - freaky, real freaky. After that I did not try it again.

The bike does not seem to have headshake though - it has yet to shake under accel. or braking. One note though, in high traction corners the bars will float a bit the first 20' or so when accelerating out of the corner - like having to steer back and fourth for no reason, but it is not a shaking or jerking motion.

But that landing twitch is making me back off and costing me confidence - What is the cause of this, any thoughts?

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well i have noticed this feel alittle on any bike when i hit real hard and am working on getting the botteming under controll -------once i get the botteming controlled and or the mid valve corrected it goes away ---------but you say it was doing it every jump,?--------was the track loose and soft everywhere ?-------do you have some friction on your head set or do you run it loose ??

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All linkages are greased with Mobil 1 synthetic grease and are in great shape. Headstock bearings are "tight" - not loose - there is no resistance to turning the bars when it is on the stand - but if you remove all of the weight (without fork tubes, etc) you can feel a little resistance.

The bike really does not bottom - actually, it may be bottoming but not once this year have I had a single wrist jarring spike - this leads me to believe that the revalve may be a bit on the stiff side or I am just not going that fast... I am bottoming my friend’s bike though so I am probably going a decent speed.

The track is hardpack, natural terrain MX. It does this twitch allot, not every lap but allot more than before I started messing around with "upgrades" like the clamps and valving. Basically, the bike has picked up a twitch that happens allot more and happens at every track I have been to this year. It was real twitchy at Redbuds last open ride. The track was fairly loamy and rutty that day. I had felt that I had made some progress with the clicker settings and it was just wacky at Redbud.

It was real bad when I first got the bike back from the revalve, and I spend a couple of days taking laps, changing clickers a couple clicks at a time and documenting the results... I have gotten it to calm down but that dang twitch has gone from out in the open and constant to twitching here and there – which in many ways is worse – when will it bite! Something is just not quite right.

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How much do you weigh? Do you have the right springs? How much oil in the forks? Those are the things I would look at...

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You may need to add some rebound dampening.

If you have too little rebound the wheel will "jack-hammer"

when landing hard. This could result in a front wheel that twitches back and forth.

Just a thought.

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well the added trail from the clamps wont do it (they make it more stable) hmm------the head set should be tighter than your running it,--you should just haft to help it around , it should not fall on its own.--but still it shouldnt twitch like that ---------mathprof may be on to somthing,--can you think back and tell if it does it while on compression ,fork --stoped ---or is the bike just comming back on rebound ,-----i know this may be hard to recall .

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My YZF250 did the exact same thing. I added alittle rebound to the forks and it stopped.

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Well, I have been trying hard to pinpoint the exact timing of the shake - my sense is that it starts either just at the bottom point of the stroke or during the rebound. This really is hard to tell though and I don't want to guess what is happening... how can I say that it is not being initiated at compression? I am hoping to get out tomorrow with a friend who can watch and see if he can tell what is happening.

For what it is worth - a couple weeks ago I was a bit confused and was changing rebound instead of compression to try to improve the ride (rebound clicker on the bottom of the fork leg, who's idea was that...) Needless to say, the bike was not doing what I predicted, but that was good because it forced me to be honest about if it had improved the ride or not - bottom line, it did seem to get better with more rebound damping but I am off 7 clicks from the tuners recommended "target" I think I am out 5 and he recommended out 12. I am not comfortable going much further and am not sure if this is the correct adjustment anyway - should be making changes to sag, or the rear compression or rebound... could it be the rear causing the front to misbehave in this specific situation?

Thanks for your interest and feedback. I have over a grand sunk and it is worse than stock! (except bottoming resistance, great bottoming resistance)

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well the 03 crf was not very off at all as far as mx goes for a wide range and levels for a stock bike------but by the same catch 22 it did not take very much shim shuffle and or mid valve dissabled to realy cause some ill affects on chassis behavyer------and the rear was more forgiving than the ft,---but anyway try to get your buddy to video you with a cam corder and see if the bike stays level or if one end seems to ride low or hop off the groud after a hit and try to see if you can get a handle on what its doing,------one thing i try to do is take a second bike to the track to test and leave it alone and ride it and see if it does the same thing as the other one that you are working with -----if you ever see a team go testing this is what they do ----they will swap forks and run them and then swap back to the other set and see whats up with those--and then the use another bike and do the same thing over and over untill the have one problem worked out before the go on to a different area to iron out --------so if you could ride another one and or let somebody ride yours and video it and get some feed back that way it will help you see where you need to go !!-----------and some of the guys run 2 to 5 clicks out from the tightest setting on rebound on the fork ,---i dont like it there , it packs for me there to much in the woops and can through me off if i hit one wrong------i run mine at 9 out ,----some of the guys will run 12 to 14 out to keep it from packing in the woops, but is hops sometimes on a hard landing with the brakes on for a hard turn after a jump and i hate that i want it to hit once and stay stuck there-----so i mean you will end up where it works for you ,--dont be to conserened wher that may be !------and it could be the rear is riding way low or high and causing a funny twitch in the ft but you should be able to see this on tape and by letting someone else ride it and you ride another one !!

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perhaps you have a tweaked rim? its just a wild guess. what you're describing is very weird. Could you have overtightened the clamp bolts which is causing the forks to bind? :cry:

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The bike is in very good shape - spokes are torqued and the rims run true - clamps are torqued properly, chain adjusted properly, about 15psi in both tires, etc... Probably not a "riding style" issue either - no problems when riding my friends bike...

One thing that I did think of - could it be the 4 stroke power? landing with the gas on does put allot of power to the ground, I always did this on my 2 stroke - is this technique wrong to use on the CRF, or perhaps I am applying too much power? If this was the case I would guess that there would have been allot of other people going through the same thing - and come to think of it, this problem did not occur when the bike was stock...

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The CRF suffers from a fast high speed rebound curcuit. This does have a effect on slap down landings. I would recommend adding rebound at first as suggested in a earlier reply.

Also since this was revalved, I would get a hold of the tunner that revalved it, and diccuss this with him , he would most likely correct this issue for you. (I would hope)

Russ

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you always want to hit with the power on ,even if it is only for a second if you can ,----as we all know it helps stiffen up the rear suspension and lets you drive foward away from the hit and helps the chassis out ,--and if you can be light on the bike at the same time with correct timming you can be so smooth that you almost dont feel the hit !!!

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Thanks for the info -

a big reason for posting here is because the tuner is NOT helping! I would send it back for the "free" valving support but I have lost trust here... and it really is not free, $35 in shipping each way, oils and seals and slider metals minumum, it will add up... I have been thinking of cutting my losses and starting over with a new tuner -

I have only contacted them for two questions total but I had do send multiple emails and many phone messages over the course of many days only to get a "you have to dial the clickers from here..." I had already dialed them till my fingers bled! (to get an answer to my second question it took over 8 days, ...he has the message he will call you later today... did you try "this" e-mail, he uses that one more... to get in contact and when it was over I felt like they thought my questions were stupid and annoying...am I parinoid, no the pushback was clear)

Thanks again for all the feedback -

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Thanks for the info -

a big reason for posting here is because the tuner is NOT helping! I would send it back for the "free" valving support but I have lost trust here... and it really is not free, $35 in shipping each way, oils and seals and slider metals minumum, it will add up... I have been thinking of cutting my losses and starting over with a new tuner -

I have only contacted them for two questions total but I had do send multiple emails and many phone messages over the course of many days only to get a "you have to dial the clickers from here..." I had already dialed them till my fingers bled! (to get an answer to my second question it took over 8 days, ...he has the message he will call you later today... did you try "this" e-mail, he uses that one more... to get in contact and when it was over I felt like they thought my questions were stupid and annoying...am I parinoid, no the pushback was clear)

Thanks again for all the feedback -

good idea, ive heard nothing but good things about pro-action, factory connection & RG3

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Thanks for the info -

a big reason for posting here is because the tuner is NOT helping! I would send it back for the "free" valving support but I have lost trust here... and it really is not free, $35 in shipping each way, oils and seals and slider metals minumum, it will add up... I have been thinking of cutting my losses and starting over with a new tuner -

I have only contacted them for two questions total but I had do send multiple emails and many phone messages over the course of many days only to get a "you have to dial the clickers from here..." I had already dialed them till my fingers bled! (to get an answer to my second question it took over 8 days, ...he has the message he will call you later today... did you try "this" e-mail, he uses that one more... to get in contact and when it was over I felt like they thought my questions were stupid and annoying...am I parinoid, no the pushback was clear)

Thanks again for all the feedback -

Save yourself the cash and just click in two more clicks of rebound damping. It'll settle down. My 03 was doing the exact same thing, and I was working on settling the push in the front and I ended up at 9 out from bottomed on the rebound. It doesnt push anymore and the landing ramp wha-tooise came to an end also. :cry:

It really amazes me. Guys will rip the suspension off the bike and ship it before they exhaust the clickers :cry:

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Shawn -

fair enough (about ripping the suspension off before exhausting the clickers...) but I have indeed tried virtually every clicker/sag/etc combo - it just does not feel right - and it makes me nervous to run any setting close to or at the limit - seems like an indication of a bigger problem...

I am too old and have had too many broken bones to take risks that could be addressed with proper attention. Believe me, I would easily have paid good money if it would have saved me from some past injuries - some which still haunt me. This sport is obvioulsy one that carries risks - I just want to have the most fun possible while feeling confident that my equipment (bike and safety) are in the best condition possible.

This thread has been a big help to me - thanks!

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Save yourself the cash and just click in two more clicks of rebound damping. It'll settle down. My 03 was doing the exact same thing, and I was working on settling the push in the front and I ended up at 9 out from bottomed on the rebound. It doesnt push anymore and the landing ramp wha-tooise came to an end also. :cry:

It really amazes me. Guys will rip the suspension off the bike and ship it before they exhaust the clickers :cry:

Amen. What is happening is your forks are deflecting off the ground from the rebound rebounding too fast. Sounds me like the tuner jacked up the rebound circuit.

To test this, go hit a table top, but don't clear it, and don't give it too much gas (this is just to test it). See if you get the sensation like you are bouncing back up. almost like if you pulled up on the forks you could get some more air. My bet is you will feel like it's bouncing back.

The CRF's IMOP (as Shawn_Mc stated) come stock with too little rebound dampening, and require a couple clicks in to slow them down to managable speeds. But with the revalve who knows what he did??

Good luck.

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