[hmcleay]

Hi Guys,

I've just inherited a set of used Fox 40s, and am part way through servicing them.
The Fox website recommends 50mL of 7wt (for pre-2010 model) in each leg for lubrication of the lowers.

Have any of you guys tried using other oil for lubrication?
I have often used engine oil in the lowers on my boxxers, and it seems to 'hang around' the bushings better than a thinner oil would.
So i'm considering also using engine oil for the lowers on the 40s, but thought i'd get some feedback first.

7wt oil seems like it would drain away from the bushings way too quicky (esp if your bike is stored upright all the time). But on the other hand, maybe it splashes around better than a thicker oil would while riding.

Have any of you experimented with different oils?

Cheers,
Hugh.

 

[Racebike]

I've tried a few different oil types (different wt.) and imho thick oil makes the fork not work as well as it is supposed to.

I rode RS Boxxer forks before and Fox 40 now, jumping up in wt made both type of forks not work as well, they felt "sticky & slow".

 

[jonKranked]

For the fox 40, the 7wt oil is to lubricate the internals, not the dust wipers. You have to lubricate the dust wipers separately. Basically, take off the lowers, clean the bushings. There is a free-fitting foam ring inside the the bushing, and basically you want to pack it with grease. Not engine grease, not normal bearing grease. Fox recommends their Float Fluid, by most people I know (myself included) use Slick Honey. It packs well and lubricates very well.

Absolutely do NOT use engine oil. They recommend a lower viscosity oil for certain reasons. I've had good luck with Golden Spectra. There are a lot of other brands of fork oil, Silkolene, Maxima, even Bel-Ray will work in a pinch (most people consider this to be on the low end of fork oils). Not only that, I have a feeling that if you ever have an issue with the fork and need it warrantied, I suspect motor oil will void any warranty.


Also, Fox's rebuild guide can be found here:

http://service.foxracingshox.com/consumers/Content/Service/Forks/40/40RC2.htm

And here's Fox's "Quick n Dirty" Dust Wiper cleaning method:

http://service.foxracingshox.com/consumers/Content/Service/QuickTech/Dust_Wiper_Seal_Quick_Clean.htm

 

[shift96]

The foam ring is not for grease, it's to soak up the oil for stanchion lubrication. That's why you should turn the fork up side down every now and then.

 

[jonKranked]

The foam ring is not for grease, it's to soak up the oil for stanchion lubrication. That's why you should turn the fork up side down every now and then.

I tried this when I first got my 40 because it was what I was told by a Fox tech. I was rather disappointed. Packing the area between the dust wiper and the lowers (where the foam ring is) with slick honey will perform much, much better.

 

[shift96]

cool man! I also pack that "void" area but I don't actually put grease on the foam ring. Thanks for the tip my Jersey Brutha!

 

[jonKranked]

I've been extremely pleased with the Slick Honey. The first time you use it, you have to pack in quite a bit, but from there on out (unless you remove the wipers and give them a very thorough cleaning, or replace them) you won't need as much. The gap/void acts sorta like a reservoir. You will notice the increase in stiction (very noticeable) on the fork when the slick honey is starting to get low (which means its time to re-pack), but when you open it up there will still be an amount of the slick honey left. Just re-pack it and you're good to go.

One thing I've also found is in regards to service time. Fox recommends cleaning the dust wipers every 15 hours of riding, and changing the oil in the fork legs every 30. In my experience, I go downhilling on the weekends, lift access, both days, so this roughly translates to 2 weeks for the wipers and 4 weeks for the oil. I've found that with using slick honey, I can go 3-4 weeks (well, weekends) of riding before I need to repack. And by then the oil is dirty enough that it needs to be changed anyways, so I can do it all in one shot.

In regards to cleaning the wipers, I check them when I'm waiting in line for the lift, and sometimes dust will build up on top of the wipers, and I just wipe it off so it doesn't get dragged into the fork.

 

[JeffKill]

I tried this when I first got my 40 because it was what I was told by a Fox tech. I was rather disappointed. Packing the area between the dust wiper and the lowers (where the foam ring is) with slick honey will perform much, much better.

Just to clarify, are you removing the foam ring, or packing it with slick honey? With the 40 there isnt a dedicated oil seal, so there isnt really anything to retain the slick honey that you'd pack in that space if you were to remove the foam ring, is there? I would assume it would just be pulled down on to the bushings and into the lowers.

Not saying your wrong, just trying to clarify for the OP.

 

[DRAKETHOMAS]

Petro based grease will partially mix with oil so yes filling with grease is not the best idea, run enduro seals and then you could as the two seals would have a small volume allowing to put grease in there.

 

[jonKranked]

Just to clarify, are you removing the foam ring, or packing it with slick honey? With the 40 there isnt a dedicated oil seal, so there isnt really anything to retain the slick honey that you'd pack in that space if you were to remove the foam ring, is there? I would assume it would just be pulled down on to the bushings and into the lowers.

Not saying your wrong, just trying to clarify for the OP.

I leave the foam ring in place (which you are supposed to). Where its positioned, it is captured and sorta "floats" (fits loosely) in between the lowers and the dust wipers (the dust wipers press into the lowers, and the foam ring goes in between the two. hence it is "captured" between them). There is a small amount of space above (typically, as the foam ring falls onto the lowers [gravity]) and that is where I pack the slick honey. It kinda blends into a groove in the lower portion of the dust wiper, and it accommodates a somewhat surprising amount of lube (SH). The gap combined with the groove is maybe 1/8" - 3/16" total.


This is Fox's step by step walk through (some of the pictures show the foam ring in relation to the wipers and lowers, but not that well):

http://service.foxracingshox.com/consumers/Content/Service/Forks/40/40RC2.htm

This is fox's "quick service" for bushing cleaning:

http://service.foxracingshox.com/consumers/Content/Service/QuickTech/Dust_Wiper_Seal_Quick_Clean.htm

This method was intended to be able to clean your wipers without dissassembling the fork, but its just as much of a hassle, and you risk scratching your stanchions.

It also shows the foam ring absorbing the float fluid, and in my experience this doesn't work as well as a Slick honey packing.

 

[JeffKill]

It also shows the foam ring absorbing the float fluid, and in my experience this doesn't work as well as a Slick honey packing.

I see. So you're packing the foam ring itself with slick honey, or just the area above it?? (sorry for being so slow )

 

[jonKranked]

I see. So you're packing the foam ring itself with slick honey, or just the area above it?? (sorry for being so slow )

I pack the area above the foam ring. I also slather a bit on the inner diameter of the foam ring itself, as well as the inner surface of the dust wiper (basically the surfaces near the dust wiper that will come in contact with the stanchions). Next time I do it I'll post up some pics. It'll be over a month, I just did it this past weekend (drunk and at Delta house at Platty no less) and I'm on vacation - and not dh'ing - for the next 2 weeks.


edit: no worries about details on the lubrication. I was a bit nervous myself the first time I did it. When I was done I realized its a total piece of cake. I'm glad to provide any help I can.

 

[JeffKill]

I pack the area above the foam ring. I also slather a bit on the inner diameter of the foam ring itself, as well as the inner surface of the dust wiper (basically the surfaces near the dust wiper that will come in contact with the stanchions). Next time I do it I'll post up some pics. It'll be over a month, I just did it this past weekend (drunk and at Delta house at Platty no less) and I'm on vacation - and not dh'ing - for the next 2 weeks.

Thats cool, I dont even own a 40 anymore myself. But I still take care of my gf's 36 float. I normally just saturate the foam ring with fork oil, then pack the wiper with slick honey. Always open to new ideas though....

 

[NJHCx4xLIFE]

Jon, I ride about the same amount on the big bike but slack with my fork service. You say you clean the wipers and pack with grease every month along with change the oil... are you changing only the lube oil in the lowers or are you changing the damper oil monthly as well?

 

[jonKranked]

Jon, I ride about the same amount on the big bike but slack with my fork service. You say you clean the wipers and pack with grease every month along with change the oil... are you changing only the lube oil in the lowers or are you changing the damper oil monthly as well?

Just the oil in the lowers. I have not yet needed to service my damper cartridge. FWIW when I bought it, it was a fork on a back-up bike from a friends race team, used maybe 10 times, and was completely serviced and rebuilt by Fox at the end of last season, and not ridden since.

 

[NJHCx4xLIFE]

Just the oil in the lowers. I have not yet needed to service my damper cartridge. FWIW when I bought it, it was a fork on a back-up bike from a friends race team, used maybe 10 times, and was completely serviced and rebuilt by Fox at the end of last season, and not ridden since.

Cool cool. Thanks for the heads up. I re-built the damper before the season and sadly only have maybe 6 rides on it so far so It should still be good. Was just curious you service schedule since it seems like you are a little more proactive than me.