Fox 40 RC2 Setups

You asked the wrong crowd. They'll tell you to rip it apart, drill holes, tap threads, change oils (not "that" oil. It's viscosity ÷(x+C²×r) will foam up too much) use the seals from a Marzocchi Monster T and the cartridge off of a 2012 Boxxer.

Just sayin'

That's certainly a reasonable method. You can also use the bracketing method. For the latter I usually get the rebound to a comfortable setting, then bracket high speed compression, followed by low speed, and then I return to rebound. The only problem I run into with bracketing is it requires a lot of runs, which leads me to using short sections of trails unless I'm somewhere with lift access. That usually results in a stiffer setup that feels fast when I'm setting it up but gets tiring pretty quickly.

If I'm not bracketing I'll set spring rate and then rebound to my own preferences, and then use the manufacturers recommendations for low and high speed compression as a starting point.

dovbush66 said:

Sorry, didn't word it properly - when you are bracketing and like your first step above, rebound is set and HSC is bracketed, does that mean you only adjust HSC and leave LSC alone? Would I be right in saying both would be at full open on your first run?

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Yes, I'd have both LSC and HSC full open on my first run. Second run I'd only change HSC to be full closed.

Blue spring is correct for ~60-75kg.
The HS:LS ratio I've discussed here a lot in the past is useful if you want to get the most out of these (excellent) dampers.

If you give the search function a good thrash you'll find more info than you ever wanted to know.

https://ridemonkey.bikemag.com/threads/2012-fox-40-breaking-in-period.251667/page-2#post-3814086
https://ridemonkey.bikemag.com/threads/2012-fox-40-breaking-in-period.251667/page-2#post-3814105
https://ridemonkey.bikemag.com/threads/2015-fox-36-harsh.276499/page-5#post-4201476

In my experience:

• The fork works best with the genuine Fox Gold 20wt for lower leg lubrication
• If changing damper oil, be sure to maintain factory cSt and VI (viscosity index) values
  
• Genuine Fox/SKF seals seem to give best lifespan:friction ratio
• Chassis updates post factory-coil version are nice for cutting the weight down, if desired

There's (still) no better fork for a DH bike.
Everyone I know who a) knows suspension, b) actually rides fast, and c) has a choice (i.e. not sponsor-restricted) is on a 40RC2. Grip2 avoided by choice (when given that choice), interestingly.
Enjoy.

Udi said:

Everyone I know who a) knows suspension, b) actually rides fast, and c) has a choice (i.e. not sponsor-restricted) is on a 40RC2. Grip2 avoided by choice (when given that choice), interestingly

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Does that includes the 2019 model?

The guy behind Novyparts, who obviously knows a bit about suspension after working for BOS and now having his own tuning workshop, is also a rather fast guy since he managed a few podiums this year in DH master.
After trying a 2019 40 air Grip2 he said that the fork is so good that he hardly find anything that need to be improved on it. He seemed rather impressed.

dovbush66 said:

Also followed your advice for a similar hs:ls balance on the rc4, really happy with it too. That shock seems to work really good at slow rebound settings, although the tune on mine isn't stock.

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Great to hear. Enjoy.

Happymtb.fr said:

he said that the fork is so good that he hardly find anything that need to be improved on it. He seemed rather impressed.

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As always, it depends on your point of comparison.
I'd take that fork over most current alternatives, and certainly, over a BOS. Funny you mention them, two guys I know who ride for the Solid team have BOS as the team suspension sponsor, but at the start of this year they were both on shiny new 40s and matching rear shocks.

"New suspension sponsor?"
"No we bought these with our own money, free stuff is nice, but taking seconds off is nicer."

You can probably gauge how much "working for BOS" means to me. Anyway, I don't have time to engage in a coil / air / rc2 / grip2 debate - it's all been discussed in the past. If someone is on any 40 with two blue adjusters, the fork likely won't be slowing them down. How they set it up might be.

@Udi , I have a fair idea of what you think about Bos and I have no interest in discussing that any further

About the RC2 vs Grip2, Fox has apparently been working on the later for the 2019 version in order to reduce friction which was its major drawback before. That's why I was curious to know if the 2019 version was covered by your earlier statement.

Happymtb.fr said:

Fox has apparently been working on the later for the 2019 version in order to reduce friction which was its major drawback before. That's why I was curious to know if the 2019 version was covered by your earlier statement.

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Haven't ridden.
Fox claimed the first iteration had less friction than the RC2 when in reality it had more. There is already relatively low friction in most dampers compared to an air spring within a telescoping chassis - particularly halfway into a realistic service interval which is where most air sprung gear starts showing deficiencies - so if someone is raving about the friction properties of a damper housed in an air-sprung telescoping fork, there's a grain of salt to be taken with it. The valving and damper curves are far more important and there was no existing problem with the RC2. So all Fox has done is created a new problem, and then maybe fixed it.

By all means send me a 2019 Grip2 if you want me to tell you how it compares.
As for BOS - you brought it up - that company is a joke: both product and service.
I love an opportunity to share what I think about them.

You seem to be in a good mood @Udi enjoy the summer!

Happymtb.fr said:

@Udi , I have a fair idea of what you think about Bos and I have no interest in discussing that any further

About the RC2 vs Grip2, Fox has apparently been working on the later for the 2019 version in order to reduce friction which was its major drawback before. That's why I was curious to know if the 2019 version was covered by your earlier statement.

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GRIP2 is a 2019 cartridge, so I'm guessing you mean 2020 GRIP2?

All GRIP2 cartridges I've seen come with the latest 70 durometer u-cup sealhead that is indeed very low friction.

Happymtb.fr said:

obviously knows a bit about suspension after working for BOS

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Happymtb.fr said:

I have a fair idea of what you think about Bos and I have no interest in discussing that any further

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You literally brought it up yourself, then decided you didn't want to discuss it.
This is the kind of nonsense that makes it easier to not post here at all.

Qualifying that someone knows suspension because they worked for BOS is like saying someone knows brakes because they worked for SRAM.

I've ridden the current Grip2 in the current chassis (2019 as tacubaya points out) and I think it feels fine. I assumed you were talking about something newer. In any case, Fox seem to improve (or attempt to improve) chassis friction and sliding performance every generation, and unfortunately with any brand there can still be unit-to-unit varation; so any friction comparison between dampers should involve swapping between them in the same chassis with damper curves matched as closely as possible. Unless your lord and savior did this, I'd be questioning whether his conclusions are about the damper, the chassis, or just the particular fork he happened to test.

Finally, there's much more to a damper than its seal/bushing friction, so I'm not even sure what conclusions you're trying to draw here. I respect that the guy at Novyparts knows a thing or two about suspension, you're just not doing him any favours here.

tacubaya said:

GRIP2 is a 2019 cartridge, so I'm guessing you mean 2020 GRIP2?

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I just realised the 2019 grip2 was launched early 2018...

Udi said:

You literally brought it up yourself, then decided you didn't want to discuss it.

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In the context, I wanted your answer to focus more on the grip2 than on Bos... it's not that I don't want to discuss Bos or any other suspension related topic with you or anybody else on that forum. It's just that you can be a bit lengthy sometimes

Like I said before, I am very curious about suspension: how they work and how they improve / impact our ride experience. I don't pretend to know everything (I don't accuse anybody here to do it either!), I enjoy the process of learning and understanding which hopefully helps me to make wise decision and cut through the marketing BS when buying a new piece of kit.

Udi said:

This is the kind of nonsense that makes it easier to not post here at all.

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Yes of course! If a guy on the internet (me) tells you the opinion of another guy you never heard of, how likely are you to believe it? Even if I didn't had mentioned Bos in the first place?

Keep on posting here, you make plenty of relevant contributions!

dovbush66 said:

you were right man. I read this thread, blacked out and woke up covered in oil, shims and metal shavings beside my 40 and a japanese love pillow with a picture of vorsprung steve taped to it

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You could have just called, now I feel left out.