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Author Topic: shocks  (Read 175 times)

Offline atvmxr

shocks
« on: November 17, 2020, 03:10:43 PM »
I dont know if all XC are like this, but I finally got all my stuff to be legal to ride the national forest in texas.  lots of big sand whoops like you find on dune trails, but also tons of 3-4" tall tree roots that were basically like ridding a trail scattered with bricks.  Very square edged and constantly yanking the bars around.  Im sure a steering stabilizer would help the side to side, but I want to ask about shock brand/rebuilder that set up shocks for really rough low-mid speed stuff, but still be able to handle jumps and whoops like you find on MX.

?
Bunch of race quads that run on premix

Online croat1

Re: shocks
« Reply #1 on: November 17, 2020, 04:09:32 PM »
Atvmxr, What did you change to be trail legal?   

Joe

Offline Jerry Hall

Re: shocks
« Reply #2 on: November 17, 2020, 06:06:34 PM »
I dont know if all XC are like this, but I finally got all my stuff to be legal to ride the national forest in texas.  lots of big sand whoops like you find on dune trails, but also tons of 3-4" tall tree roots that were basically like ridding a trail scattered with bricks.  Very square edged and constantly yanking the bars around.  Im sure a steering stabilizer would help the side to side, but I want to ask about shock brand/rebuilder that set up shocks for really rough low-mid speed stuff, but still be able to handle jumps and whoops like you find on MX.
?

Even though you may be hitting the tree roots at low MPH, the shock action moves the shock piston in the high speed mode where a lot of fluid needs to flow through the piston without generating very much compression damping.  This requires a compression shim stack that can open wide without needing a lot of pressure to lift the leaf valves.

Woops and jumps moves the shock piston relatively slow and needs a lot of compression damping to provide more resistance to bottoming as compared to hitting the tree roots.

I do not know of a compression valve plate stack that will handle both extreme ends of the requirements you stated.  I have seen and tried a lot of "progressive shim stacks"  but have yet to have them work like theory says they should.   Gas pressure should not be used as a tuning tool but lowering the gas pressure will usually improve the square edge shock response, but when the gas pressure gets too low, the shock will turn into a pogo stick.  There is a fine line of finding just the right gas pressure and the shock becoming a pogo stick.

« Last Edit: November 17, 2020, 06:09:52 PM by Jerry Hall »

Offline Tbone07

Re: shocks
« Reply #3 on: November 18, 2020, 01:32:27 PM »
I dont know if all XC are like this, but I finally got all my stuff to be legal to ride the national forest in texas.  lots of big sand whoops like you find on dune trails, but also tons of 3-4" tall tree roots that were basically like ridding a trail scattered with bricks.  Very square edged and constantly yanking the bars around.  Im sure a steering stabilizer would help the side to side, but I want to ask about shock brand/rebuilder that set up shocks for really rough low-mid speed stuff, but still be able to handle jumps and whoops like you find on MX.

?

Might be helpful to talk to a reputable shock builder that does a lot of XC stuff. Derisi is the first builder that comes to mind.

Are you running Flexx bars or a precision bar mount? That might help on the smaller stuff too. Flexx bars work wonders for me
LED Performance 350 Sphynx - XC Machine
Laeger's-Roll-GThunder-HLS-PEP-HiPer-GBC

RIP Laz

Offline atvmxr

Re: shocks
« Reply #4 on: November 18, 2020, 02:48:18 PM »

Even though you may be hitting the tree roots at low MPH, the shock action moves the shock piston in the high speed mode where a lot of fluid needs to flow through the piston without generating very much compression damping.  This requires a compression shim stack that can open wide without needing a lot of pressure to lift the leaf valves.

Woops and jumps moves the shock piston relatively slow and needs a lot of compression damping to provide more resistance to bottoming as compared to hitting the tree roots.

I do not know of a compression valve plate stack that will handle both extreme ends of the requirements you stated.  I have seen and tried a lot of "progressive shim stacks"  but have yet to have them work like theory says they should.   Gas pressure should not be used as a tuning tool but lowering the gas pressure will usually improve the square edge shock response, but when the gas pressure gets too low, the shock will turn into a pogo stick.  There is a fine line of finding just the right gas pressure and the shock becoming a pogo stick.


Thank you for the explaination


Atvmxr, What did you change to be trail legal?   

Joe

Well the main thing was finally taking that ATV safety class.  put on a FMF Q spark arrestor silencer.  Texas OHV sticker
Bunch of race quads that run on premix

Offline number5

Re: shocks
« Reply #5 on: November 24, 2020, 06:59:05 PM »
Like jerry said what I have requested to meet my needs in woods racing you cannot have the best of both.

 

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