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First Impressions – 2012 Fox RP23 Shock with Adaptive Logic

2012 Fox RP23 Factory Tune rear shock with boost valve and adaptive logic review
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2012 Fox RP23 Factory Tune rear shock with boost valve and adaptive logic review

After unveiling all the new tech and products at Sea Otter this year, Fox’s marketing guy collected my bike model information (Niner Jet 9) and sent over a new shock based on the appropriate Factory Tuned option (read: matched the OEM internal compression, rebound and boost settings). I swapped out my OEM Fox RP23 shock for a 2012 model with both Boost Valve and Adaptive Logic between laps at the BURN 24 Hour Challenge so I could get back-to-back impressions, and I have a few subsequent rides on it as well.

As I was bolting up the new model, I was thinking “Yikes, am I really going to be able to tell a difference?”

The answer, in a nutshell, is ab-so-freakin-lutely. The difference is not subtle. Not only does it feel smoother, but it feels like I gained an inch of travel. Make the jump for specifics…

WHAT’S NEW:

2012 Fox RP23 Factory Tune rear shock with boost valve and adaptive logic lever settings

For me, this was the first time I’ve had a Boost Valve shock on my Niner, so I went from basic RP23 to the latest and greatest. For those looking to upgrade from a bike that’s a few years old, this is the likely scenario. The only difference is if you buy an ‘off the shelf’ aftermarket Fox shock or order it from them with the appropriate OEM settings. Mine matched up, and your current shock should have the internal settings labeled around the base of the air can.

Boost Valve: Bottom out performance off drops is much improved with the Boost Valve, giving the shock more of a bottomless feel by ramping up near the end to prevent full smackdown at the end of the stroke. On the bike, that gave it a more controlled feeling, both coming down and during the rebound cycle, which makes things much more predictable during and just after landing. It also gave the shock a firmer feel during hard cornering in the berms and in G-out’s like when transitioning from a rapid descent into a sharp radius bottom or incline.

Adaptive Logic: Essentially, this is ProPedal in reverse. We covered the tech in much greater detail here, but what you’re getting is a firmer “3” setting when flicked over, and 0-1-2 settings with various low speed compression damping levels from wide open to somewhat firmed up.

2012 Fox RP23 Factory Tune rear shock with boost valve and adaptive logic comparison to original RP23

My original OEM shock on the left, 2012 model on right.

2012 Fox RP23 Factory Tune rear shock with boost valve and adaptive logic review and actual weights

Weight is virtually identical…could just be that the new one is a bit low on oil…

RIDING IMPRESSIONS

In addition to what’s mentioned above, the overall impression is a much, much plusher shock. Mind you, my test version (sadly) didn’t come with the Kashima coating and it’s still noticeably smoother.

Perhaps the only negative thing I could say about the Niner Jet 9’s performance is that it gets bogged up just a bit on hard, square-edged bumps. With the new shock, that virtually disappeared and I noticed that I was flowing over logs and things that used to slow me down a bit. Running through rock gardens and rooty sections were much faster. And, lest anyone think it was mental, my first lap with the shock was on my 4th total lap during the BURN 24 hour and immediately following my 3rd (after a quick pit stop to swap them out). I ran the same air pressure (150psi) in both, but have since upped the new one to 160psi with no real noticeable difference in smoothness. Sag seemed about right at both pressures, actually.

As for total firmness in “3”, it’s still not anywhere close to a lockout, but it kept things fairly still during seated and standing pedaling. Honestly, this has as much to do with suspension design as with the shock, but overall I like the flip-flip they’ve done with ProPedal so that you can run it loose to medium on one end, then just go firm when the climbs come. It’s a smarter layout.

Now, I’m wondering if my original shock was a bit too firm…

I’ll be testing this for a while and will follow up later in the year with a long-term report.

ISSUES

2012 Fox RP23 Factory Tune rear shock with boost valve and adaptive logic review 2012 Fox RP23 Factory Tune rear shock with boost valve and adaptive logic review

While it hasn’t seemed to hurt performance, the shock did come out of the box with a bit of oil on it. At first, I thought it was just leftover from assembly, but after it sat for a few days installed, there was noticeable oil around the seam at the top of the air can and more oil than normal coating the stanchion. It’s been on several long rides now with no issues, but it may end up going back to Fox for a quick look if it starts drying up.

2012 Fox RP23 Factory Tune rear shock with boost valve and adaptive logic review

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alloycowboy
alloycowboy
13 years ago

Yes, but did the shock actually make you faster or did it just play mind games with you?

Steve
13 years ago

You are a brave man trying it in the middle of a race. Cool write up.

Bikerumor
13 years ago

Well, considering my 4th lap was about as fast as my others, I’d say it could technically be faster. Back on my local trails I definitely felt faster and smoother.

Sailor
Sailor
13 years ago

My Pivot 429 came with the boost valve shock(but not adaptive logic). I hated that thing. Pulled it off and put a spare RP23 that was off of my Intense 5.5(fortunately it fit) –Instantly better riding. Boost valve may be great for some, but it’s not for everyone. Kills small bump compliance–at least on my bike.

mountguitars
mountguitars
13 years ago

fox’s seals sucks. that’s why for next year, they’ll be using SKF seals. thank god! and thank god for enduro seals. i just changed the seals on my F100 and these are absolute way better than fox’s.

Yonathan
Yonathan
13 years ago

It is interesting that you find the new shock “smoother” as there is no obvious reason for that (no Kashima coating, similar construction).

Do you think it might have something to do with the wear of the bushings on your old shock (compared to the new bushings on the new one)?

Mr. P
13 years ago

That leaking oil looks bad. The lubrication in the air chamber is a grease. The only oil in the shock is in the damper and it is under pressure (floating piston/part of the boostvalve system) and should be completely air free.

The leaking oil can also lubricate seals beyond what is normal for a more active feel.

Nice write up and test! Notably the back to back laps in a race.

P

Slow Joe Crow
Slow Joe Crow
13 years ago

How does the Boost Valve’s action and performance compare with the DRCV secondary air chamber on the shocks Fox makes for Trek?

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