Fox 34 CTD sucking down in travel?

[nitro01]

Hey guys and gal's

Got a set of the top end Fox 34's (CTD, Trail Adjust, Kashima, TALAS) 160-140 mm on my Trance SX ADV and they are sucking down a solid 6-8mm in travel with the bike completely unloaded....

Anyone else experiencing this problem? They've been apart for servicing a few times, had a full upper replacement when I dropped it on a rock and scratched and dented the f*ck out of them (this needs to be in "Confessions from the farkwits") and have had no problems thus far with them!

It's annoying the life out of me because I can't figure out why and they are making my nice slack bike less slack!

Thanks for any help!

Nitro

 

[ChrisJC]

could it be stiction in your wiper seal? My fox 32 was doing this a bit and after sticking some lube on the stanchions, cycling them, and repeating they loosened up quite a bit. Just a thought!

 

[nitro01]

Yeah, could be. I lube before every ride, pump and pump and wipe off excess.

Will need to get some real noice choice as lube for them and try again!

Cheers

 

[schred]

Can you accurately measure pressures before and after this happens?

Not sure its relevant but one of the old issues was oil migrating from lowers into the air chamber, but I don't see why that would result in a pressure drop but but may provide a pathway for air transfer.

Anyway the quickfix was to remove the foam oil ring under the air piston.

 

[stirk]

Could it be the negative spring is overpowering the positive spring with no weight on the bike.

Is negative spring coil or air?

 

[teK--]

Could it be the negative spring is overpowering the positive spring with no weight on the bike.

Is negative spring coil or air?

This.

Your body weight and air spring pressure is too low therefore the fixed rate negative coil spring is causing the fork travel to reduce from the full 160.

There is no fix for this but to buy a fork with an air negative spring.

On mine can't get full 160mm travel unless running 145psi which of course is way too stiff.

Don't forget the last 7mm or so of the stanchion is unusable, so measure how much is visible above the wiper seals then deduct 7mm to calculate actual useable travel.

 

[nitro01]

This.

Your body weight and air spring pressure is too low therefore the fixed rate negative coil spring is causing the fork travel to reduce from the full 160.

There is no fix for this but to buy a fork with an air negative spring.

On mine can't get full 160mm travel unless running 145psi which of course is way too stiff.

Don't forget the last 7mm or so of the stanchion is unusable, so measure how much is visible above the wiper seals then deduct 7mm to calculate actual useable travel.

teK- You're a legend, thanks for clearing it up mate

All help appreciated

And just for your reference I run 115ish psi, but it's still pretty soft with a nice ramp up

Thanks all

 

[teK--]

teK- You're a legend, thanks for clearing it up mate

All help appreciated

And just for your reference I run 115ish psi, but it's still pretty soft with a nice ramp up

Thanks all

I run 120psi it is good all round and i get 153mm travel (160mm stanchion showing)