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Discussion Starter · #1 ·
my current bike came with fox 34 2019 performance grip fork. i have read and heard that sometimes forks ship with low bath oil so i wanted to check.
to my surprise, checking oil volumes revealed, that this fork uses 5w teflon infused oil in damper leg. used to be 20w gold in both. so 2 questions i have:

1. can i use 20wt gold in both. doing quick search, found that some people suggest 20wt in both will not be a problem, does this still hold true?

2. back in 2012 when i started changing bath oil in my old 36fit myself, there was a thread regarding 20wt substitute, and one of the option people were suggesting was to use mobil 1 10w30 oil. which is very cheap and readily available in car stores here. i have been using this oil as bath oil in my 2012 fox 36, and then in 2018 pike, no issues. i assume it is still good alternative to w20 gold? or is there a consensus there is something better now? i would want something that is readily available in stores or at least online that does not have to ship from out of states and not too expensive, i change bath oil quite often since i ride a lot.

thanks
 

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Some prefer to use 20 Gold in the damper side lower. The only downside is it will (very) slowly get ingested by the damper and mix with the 5W damper oil. This is why Fox specified the 5W teflon oil for the damper lower. FiT4 dampers also ingested oil, but had damper shaft seals that were better so ingested oil even more slowly, but they also had more friction. The Grip design with self purging damper was intended to reduce that friction.
 

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I haven’t seen a fork with low bath oil in years, but it is worth greasing the dust wipers and soaking the foam rings

Ingesting oil into the damper is so slow that it doesn’t affect anything
 

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It has happened with every sealed damper ever, its just some do it at a different rate to others. Open up a 10 year old fit fork thats never had a damper service and you will see it is pumped up and impossible to compress all the way

The only thing that changed recently is companies are giving the excess oil a way to vent while keeping the damper sealed and without air
 

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moaaar shimz
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Do not run 20wt Gold as lubrication on the GRIP side, stick to the 5wt Teflon on that side. Grip dampers have a one way seal on the sealhead which allow oil to be sucked in while a bleed system up top removes excess oil when the damper is compressed past a certain point. If you run 20wt oil for lubrication on the damper side it will get sucked into the GRIP damper, mix with the 5wt inside the damper and the result is no bueno.
 

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Do not run 20wt Gold as lubrication on the GRIP side, stick to the 5wt Teflon on that side. Grip dampers have a one way seal on the sealhead which allow oil to be sucked in while a bleed system up top removes excess oil when the damper is compressed past a certain point. If you run 20wt oil for lubrication on the damper side it will get sucked into the GRIP damper, mix with the 5wt inside the damper and the result is no bueno.
20wt oil has been mixing with the damper fluid ever since it was brought out with no problems, the benefits of using a proper bushing lube vs 5wt are much bigger than any potential harm from a tiny amount of 20wt in the damper.

Maybe don't use 50ml of it but otherwise its fine
 

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Do not run 20wt Gold as lubrication on the GRIP side, stick to the 5wt Teflon on that side. Grip dampers have a one way seal on the sealhead which allow oil to be sucked in while a bleed system up top removes excess oil when the damper is compressed past a certain point. If you run 20wt oil for lubrication on the damper side it will get sucked into the GRIP damper, mix with the 5wt inside the damper and the result is no bueno.
Every cartridge damper ingests and mixes bath oil, it's not an issue. The main thing with the Grip is to make sure the damper is completely full first. Otherwise it will suck in all your bath oil!

Also replace the token-effort 10x15x4 wiper seal in the grip seal-head with a 10x3 o-ring.
 

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Discussion Starter · #10 ·
Every cartridge damper ingests and mixes bath oil, it's not an issue. The main thing with the Grip is to make sure the damper is completely full first. Otherwise it will suck in all your bath oil!

Also replace the token-effort 10x15x4 wiper seal in the grip seal-head with a 10x3 o-ring.
thanks everyone, i will stick to my mobil 1 as bath oil then.

Dougal, why are you suggesting this seal swap? is there a known issue there? do you know of any videos i can watch so that i know what i will be doing ahead?

thanks
 

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grip damper rebuild video can be found here
https://www.ridefox.com/fox17/help.php?m=bike&id=915

they dont address seal head seal though, they just want you to replace entire sealhead.

i wonder what are the tuning possibilities for damper assembly. will lighter oil do any good to provide less damping?
from what i remember fox 5wt teflon infused is arounf 15cst
i have on hand redline 2.4wt susp oil that is around 8cst as well as maxima 3wt that is around 13cst.
 

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moaaar shimz
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20wt oil has been mixing with the damper fluid ever since it was brought out with no problems, the benefits of using a proper bushing lube vs 5wt are much bigger than any potential harm from a tiny amount of 20wt in the damper.

Maybe don't use 50ml of it but otherwise its fine
This customer ran 20WT Gold for lubrication on the GRIP side and the oil we poured out of the damper was considerably more viscous.



I haven't seen lubrication issues with the 5WT Teflon and it doesn't surprise me considering the volume specified is pretty big.

But to each his own, we stick to Fox's specifications because our customers and the Fox distributor expect us to.
 

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Bump.

When people are substituting fox gold for 5wt in the lowers... are they still using the full 40ml in that leg? Thats a lot more than any other current fork! I service often anyway, would lowering the volume to 20ml reduce ingestion?
 
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