Jump to content

Fox fork seals


LBKloppers

Recommended Posts

This is NOT a RS against FOX issue but it is a rant.

I ride a Scott Spark 27,5 plus with a Fox 34 boost fork. It is a lovely ride suiting my kind of riding like a glove, but the Fox Fork the bike came out with has a quirk I absolutely hate. In my endeavours to resolve the matter I have replaced and serviced the forks using the lbs and other times I did it myself. It's a pretty simple task with the available service kits. 

BUT

The fork has a severe sticktion problem. I need to bump the fork really hard on the first time out to overcome the sticktion. The fork will then be quite smooth but as the distance increases while riding the dirt, the dust carried by the tires collects on the stanchions. It appears this dust contributes to the sticktion and it will get worse until I give it a huge bump again. I have tried lubing the stanchions before every ride, but the same thing happens over and over.

All the recommended lubes were used when the seals were replaced with new ones and I even short-serviced one set because I got the impression something was very wrong with the fork. It turns out there are several contributing factors and I would like to hear the Hubber's opinions on these.

I noticed the stanchions become very clean and dry in a short time even after I started the ride with fresh lube on the stanchions. My bike has a Fox mudguard, but it is more of a show than anything else (South Africa is drier than muddy and these things are mostly designed for a wet, muddy Europe). Most of the dust collects on the front of the stanchions leading me to assume that the Fox mudguard deflects the dust up and the bike then rides into the suspended dust. I measured one of the seals and I found the ID to be 33mm (34mm fork). That is quite a tight fit.

1. Do you think the 1mm smaller diameter is contributing? 

2. Do you think I over-service? I once had a bike with an RS Reba that was visibly more lively than the Fox and I hardly ever serviced it.

3. And why in the world can someone in the manufacturing line not design a proper catch-and-deflect dust guard for those who ride in the dry? Surely avoiding dust from collecting on the stanchions will be beneficial.

4. Am I the only one?

Link to comment
Share on other sites

My experience of fox: 

1. the air shaft comes from the factory with way to much grease... do a air shaft service and use the correct amount of slick honey. 

2. on 2 sets of fox I had the fork bushing were way to tight. I sent them in to Push to be corrected and came back smooth as silk. 

Not sure if Stoke or RBC can sort out tight bushing for you?

Yes my RS have always felt way better out the box. but get the Fox sorted and its brilliant. 

Link to comment
Share on other sites

This sounds like the negative air chamber is not charging properly, which is usually caused by too much grease on the air spring or a bushing tolerance (both as @DuncanDoughnuts suggested). Dust will have nothing to do with the stiction, unless the inside of your fork is literally full of it. I'd suggest sending the fork to someone like RBC, Cogent Industries, Stoke Suspension or SGB Service Centre for a full strip and rebuild. They'll be able to check everything is in spec and correct any issues.

Link to comment
Share on other sites

Definitely not the seals, sounds like there are bigger issues at play there. Could be a number of issues, from tight bushings to front axle spacing being slightly out to air spring seals to a pinched foam ring. The only way to find out is to have someone who knows what they're doing have a look at it for you.

I find many LBSs, even those with otherwise decent mechanics, don't have anything more than basic knowledge of suspension and will often skip over crucial steps because they don't understand the issue. (This is not a dig at your LBS, just an observation from more than 10 years in the game.)

You mention fresh lube on the stanchions - forks lubricate themselves from the inside. Anything you put on the outside will be wiped off by the seals on the first stroke. Rather skip the snake oil and do a lowers service every 50 - 75 hours.

Link to comment
Share on other sites

15 hours ago, droo said:

Definitely not the seals, sounds like there are bigger issues at play there. Could be a number of issues, from tight bushings to front axle spacing being slightly out to air spring seals to a pinched foam ring. The only way to find out is to have someone who knows what they're doing have a look at it for you.

I find many LBSs, even those with otherwise decent mechanics, don't have anything more than basic knowledge of suspension and will often skip over crucial steps because they don't understand the issue. (This is not a dig at your LBS, just an observation from more than 10 years in the game.)

You mention fresh lube on the stanchions - forks lubricate themselves from the inside. Anything you put on the outside will be wiped off by the seals on the first stroke. Rather skip the snake oil and do a lowers service every 50 - 75 hours.

I do service the fork lower frequently. There is nothing wrong with the foam rings. Just dirty. I think you're right about the oil seal wiping off the light oil on the stanchions, but it does initially improve the fork movement while the oil is still fresh and present. I agree with your sentiment about the LBS, but that is part of a much bigger problem in the technical world. It's easter weekend and I am away, but I certainly am going to explore the Air shaft recommendations with too much grease. Finding the Fox tutorials about the Air shaft is not so easy though.

 

Have a great Easter weekend everyone!

Link to comment
Share on other sites

1 hour ago, RobertWhitehead said:

Here's my 2c: Fox is way smoother and better than RS. There's specialist in the field of forks and shocks for a reason. 

It doesn't matter. I rode with both and on a long ride there are no real-world measurable differences. The human body is immensely adaptable and your body overcomes those differences without you realising it. But even if you're right, then so much more reason to address the issues I have, because at the moment, my Fox sucks!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Settings My Forum Content My Followed Content Forum Settings Ad Messages My Ads My Favourites My Saved Alerts My Pay Deals Help Logout