Fox 34 Adjustment

[Dee Hubbs]

I have run into this problem on several Fox forks. The equalization port is clogged with excessive grease from the factory. What winds up happening is you add pressure and it squeezes past and fills the negative chamber, then when you lower the pressure it can't get out. You have too much pressure in the negative, and it pulls the fork down (super soft).

It's a problem with Fox, I have fixed several on friend's bikes. And mine. And the bike shops don't talk about it, maybe they are trying to downplay it, or they don't know. But it's a very common problem from what I've seen, I've fixed lots for my friends. New bike, Fox fork, sucks down. "OK, here we go again".

You have to pull the lowers, and clean out the grease from the port channel, then re-assemble, and it will work properly.

FWIW, I typically run much lower pressure than Fox recommends in my forks. I'm 200 kitted and run 60psi on a Fox 36/170mm. High Speed Bros can run what's on the label, but that makes no sense for Joes.

Body weight in lbs is typically close to what's needed for the rear (shock), but 1/3-1/2 for fork.

The factory assumes that the fork will never be serviced. So they grease it for the worst case scenario. This is how much grease they put on the air spring:


This is how much grease you need:


I pull all new forks apart and remove the grease from the air seal.

[SJG]

LMAO

[skideeppow]

Great. That is so out of my league on self servicing. Bike shop is 3-4 weeks out on service.

[toast2266]

Great. That is so out of my league on self servicing. Bike shop is 3-4 weeks out on service.

I'm skeptical that too much grease is your issue. Grease gumming up the transfer port definitely can be an issue, but what you've described in this thread doesn't sound like a gummed up transfer port.

Did you only inflate the fork once? If you just inflate it to the recommended pressure and call it good, that won't work - a bunch of that air will flow into the negative air chamber, leaving you with less pressure in the positive chamber (and thus a very soft fork). Double check your air pressure.

If that doesn't solve your problem, swing by a shop and get them to bounce on the fork. See if they think it feels weird. If it's a gummed up transfer port, they should be able to diagnose that pretty quick. They can also probably tell you if you just need to add more air.

[El Chupacabra]

To the OP: do you have a different shock pump you can use to check your PSI?

[Gunder]

These forks are dead fucking simple. All they have is an air spring and a damper cartridge. So the best way to diagnosis it is a simple process of elimination. You can easily do the following at home in less time than it takes to drive to a bike shop.

First, inflate the fork to proper PSI to give you 20-30% sag. Write down the PSI. Remove pump.
Second cycle the fork several times.
Third reinstall pump and check PSI. If it has decreased by more than 10% you have an issue with the air spring not sealing. If not, there is nothing wrong with the air-spring. IF there is an issue with the air spring, you need to do the following in this order; A, check the top cap is tight, B, the air valve in the top cap is fully screwed in. C, pull air spring clean and inspect the inside of the fork sanctions for obvious ear / scratches. D, Spend $30 on a new air spring, FYI you can put a longer air spring in to increase travel or a shorter one to decrease travel if desired.
4, Now that you have determined if the air spring is good move on to the damper side, turn all adjustments fully counter clockwise so the system is fully open.
5, cycle the fork a few times. IT should be VERY FAST and feel like a pogo stick.
6, Turn Rebound adjustment full in clock wise.
7 Cycle fork again, it should be noticeably slower to return to full extension. If not there is an issue with the rebound valving in damper, if not, Rebound functions correctly. Adjust it somewhere in the middle to your liking. I personally run mine pretty fast, so only a few clicks clockwise from fully open.
8, turn the compression adjustments fully clockwise.
9, Cycle the fork, it should feel VERY STIFF, almost ridged, if not there is an issue in the compression dampening.
Note, if you have both high and low-speed compression adjustments, you need them to be both fully in / out as described above, then set the high-speed compression where you want and then move on to doing the same test with just the low-speed. Chances are if there is an issue with the compression circuit damper it will be with all of the compression high/ low.
10, Adjust the compression dampening to where you like it and go ride.

Any idiot can do a lower service and an air spring service at home without any special tools. Hell my 5 year old can even do it with some instruction.
All you need is a 2.5mm hex to remove the brake hose retainer, a 5mm heat to remove the caliper. Then remove the wheel. Use a screwdriver to release the air from the air spring valve under top cap. use a 10mm socket to loosen the air spring shaft, but dont remove the nut, with socket still on nut, hit it with a hammer to diss lodge the press fit from air spring shaft in lower. Place an oil pan under, or even a yogurt container to catch the oil, remove nut and drain. Then do the same with the compression side using a 15mm socket. Once drained, and the nuts removed, grab the lower section of your fork and pull it off. Clean it, with either isopropyl alcohol or I like Maxium suspension clean for this. Pry, dust seals out of it using a tire lever. Install new dust springs using a large socket and a hammer (special tools make this quicker but are not needed). Put a light coating of Slickoleum grease on the dust seals and and slider lowers back on, then flip bike over and add the recommend amount of oil. I like using a large syringe for this. Once again I can do that service in less time than it takes to drive to a bike shop. For air spring, all you need to do once the lowers are off, is remove top cap ( special sockets are ideal for this, but not needed, you can use an adjustable wrench). Then on the bottom of the lowers there is a retaining ring, use a pick to remove it. Once the ring is out the air shaft can be pulled right out. Lube it lightly with Slickoleum and reinstall.

FYI it is widely known that Sram Butter, and Slick Honey are the EXACT SAME grease as Slickoleum, just rebranded, but Slickoleum is a hell of a lot cheaper to buy.

[skideeppow]

Call me an idiot. The shock doesn’t have lock out, just compression adjustment. Just thought all front shocks have lock out to climb?
I guess I need to adjust my riding style.

[XtrPickels]

You can dial up that low-speed adjuster to help with some of the bob, but it won't be lock-out levels of support.

[adrenalated]

Call me an idiot. The shock doesn’t have lock out, just compression adjustment. Just thought all front shocks have lock out to climb?
I guess I need to adjust my riding style.

Most forks don't have lockouts. A few do. Neither of mine do, and I don't notice any bob in the fork when climbing. Shock yes, fork no. I'm not really sure what you're doing but if the fork is set up properly and you're not doing anything super weird I really don't think it should be an issue.

Again, how does it feel when descending?

[toast2266]

Call me an idiot. The shock doesn’t have lock out, just compression adjustment. Just thought all front shocks have lock out to climb?
I guess I need to adjust my riding style.

These days, the only forks with lockouts tend to be designed for xc racing. The reality is that you're not losing much energy to fork bob during normal riding. Maybe a bit for out of the saddle sprinting (hence the lockout on xc race forks). Since uphill efficiency isn't a huge concern with forks, they're generally designed to optimize performance on descents and rough terrain. So as you're fiddling with your settings, keep that in mind.

[skideeppow]

^^Thanks for the info. I will work on the forks adjustment.

[skideeppow]

You can dial up that low-speed adjuster to help with some of the bob, but it won't be lock-out levels of support.

Thanks good to know.