Fox fit damper service/rebuil - how often?

ChrisJC

Likes Bikes and Dirt
I have seen it recommended that a full damper service should be done every 150 hours or thereabouts. At around $130 for a seal/oil change and bleed, it isn't excessive but considering a new fit 4 can be had from $250, it seems to make more sense to wait till it craps itself and just replace it. I can change the damper oil and bleed and I'm wondering whether anything more needs to be done as a regular thing?

Cheers
C
 

Minlak

Ask me about HoboBlo franchise opportunities
I get all my shocks serviced once a year currently. Seems to be working ok for me no matter what shocks I have at the time.
 

c3024446

Likes Bikes and Dirt
Following this. With my bikes, i just do seal and oil changes and don't touch the damper itself unless it's broken or not working properly after the oil change (taking about open bath Fox here)

With the cartridge dampers like the FIT, if i owned one, i'd try to change the oil in the cartridge, but that's it. If the damper doesn't work, I'd send it to a pro or replace it.
 

slimjim1

Likes Dirt
I'd just do a lowers service every 50 hours. I wouldn't even touch the damper unless there was something wrong with it. I've never done anymore than that on any of my bikes and some of them were getting quite old, never had an issue.
 

ChrisJC

Likes Bikes and Dirt
I'd just do a lowers service every 50 hours. I wouldn't even touch the damper unless there was something wrong with it. I've never done anymore than that on any of my bikes and some of them were getting quite old, never had an issue.
I haven't had a great run with dampers. Most recently the fit damper in my Factory fork developed a clunk which was remedied by an oil change and bleed. Possibly air in the system. But yeah, I'm with you, I'd rather not touch the damper unless absolutely necessary. Lowers are pretty straightforward.
 

styler

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If the damper is working correctly I do a oil change on the fit cartridge with out any seals/rebuilding. I only rebuild when something fails.
 

chrischris

Likes Dirt
I'd love to hear a reply / answer from one of the Aussie servicing crews. Cyclinic, NS, etc. I'm certain that more info would get all of us paying more attention to needed areas.
 

ChrisJC

Likes Bikes and Dirt
I'd love to hear a reply / answer from one of the Aussie servicing crews. Cyclinic, NS, etc. I'm certain that more info would get all of us paying more attention to needed areas.
I worked in the pneumatics game for 15 years and air seals used in actuators and valves are made from the same material as used in shocks (generally nitrile/buna n). Valves we used to sell were rated for at least 100 million cycles. I find it hard to believe that any internal seal would wear out with a few hundred hours of use.
 

Warp

Likes Dirt
I worked in the pneumatics game for 15 years and air seals used in actuators and valves are made from the same material as used in shocks (generally nitrile/buna n). Valves we used to sell were rated for at least 100 million cycles. I find it hard to believe that any internal seal would wear out with a few hundred hours of use.
Yeah, internal seals should not go away that quick. But then, most cartridges have only critical seals at the seal head where the shaft enters the cartridge. It is not really rare for these seals to allow oil from the semi-bath to the cartridge or fail and dump the cartridge oil into the leg... or simply to ingest some air causing you to have to bleed the cart.

Also, bike parts are not as soundly built as most industrial parts because of weight restrictions. Again, not disagreeing and not calling OK to have to service a cartridge every other week. Just stating that maintenance intervals on cartridges should be reasonably longer but not as good as other industrial applications.
 

Live2DieTrying

Likes Bikes and Dirt
Rebuilding a fork cartridge really isn't very hard, so long as you have the tools to open it up.
Fox have full service instructions listed on their website, which outlines every step of dis/re-assembly and rebuild kits are available online or through a fox dealer.
Its good practice to change the cartridge fluid every few months of consistent use, or at least once every year. Keeps the fluid fresh and clean from contamination, and gives you the opportunity to check whether anything is wearing out on the inside. (Better to know whats going on rather than wait for it to fail completely and possibly damage the entire cartridge.)

There are plenty of threads all over the internet about rebuilding any given fork. Just do some research before diving into it, and you'll be fine!!
 

ChrisJC

Likes Bikes and Dirt
Rebuilding a fork cartridge really isn't very hard, so long as you have the tools to open it up.
Fox have full service instructions listed on their website, which outlines every step of dis/re-assembly and rebuild kits are available online or through a fox dealer.
Its good practice to change the cartridge fluid every few months of consistent use, or at least once every year. Keeps the fluid fresh and clean from contamination, and gives you the opportunity to check whether anything is wearing out on the inside. (Better to know whats going on rather than wait for it to fail completely and possibly damage the entire cartridge.)

There are plenty of threads all over the internet about rebuilding any given fork. Just do some research before diving into it, and you'll be fine!!
I'd have a go if I had the tools; however the price of the piston removal tool alone is upwards of $150. What I can't seem to work out is if it is necessary to strip the damper down this far? I had a look at the Fit 4 damper and it seems doable without specialised tools.
 

tomacropod

Likes Dirt
Fit cartridge, only two things ever fail - bladder splits, or the lower seal head wears out, leaking oil into lowers.

The cartridge will accept oil from the lowers into the bladder over time, increasing the pressure in that bladder. It is important to drain and bleed the damper every 12 months or so. Full rebuild only when required. A normal fork service from a shop or technician should include this.

You don't need a bleed tool particularly, a piece of tube stretched over the top of the damper will act as a reservoir so you can cycle the air out.

In winter, you may need to pop that oil into the kettle for a bit before attempting to get the air out of it.

- Joel
 

link1896

Is not a gynaecologist but will look at your fork
Fit cartridge, only two things ever fail - bladder splits, or the lower seal head wears out, leaking oil into lowers.

The cartridge will accept oil from the lowers into the bladder over time, increasing the pressure in that bladder. It is important to drain and bleed the damper every 12 months or so. Full rebuild only when required. A normal fork service from a shop or technician should include this.

You don't need a bleed tool particularly, a piece of tube stretched over the top of the damper will act as a reservoir so you can cycle the air out.

In winter, you may need to pop that oil into the kettle for a bit before attempting to get the air out of it.

- Joel
How does 20wt Gold taste in your coffee?
 
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