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2009 SX Trail/ DHX 4.0 coil setup

2853 Views 7 Replies 6 Participants Last post by  Mathok
I'm still dialing in my rear suspension on my 09 SXT I. The current coil is a little weak (>35% sag) and I just got a 50lbs heavier spring from my buddy, but haven't installed yet to check it out.

However, just curious what other riders w/ this frame and a appropriately sprung DHX 4.0 coil (or DHX 5.0 coil) are using for their settings (Rebound, ProPedal, Boost Valve).

Undersprung, I was running:

~195-200 lbs rider weight (~175lbs rider + 20-25lbs pack/armor/gear/H2O/etc.)
-600# Fox steel coil
-5 clicks R in from full fast
-6 clicks PP in from full open
-175psi Boost Valve
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Since I just put a downpayment on a shop demo '09 SXT 1 with a DHX 4, I'm really interested in this thread, but I don't have anything to contribute until the snow melts.

I guess this is just a bump to keep it on the first page.
550lbs spring, 25% sag, 160psi boost valve, 2 clicks pro pedal, 2 clicks rebound.
how much do you guys weigh. and whats with the boost valve? i have the 08 sx with the dhx 4.0. and know nothing of this boost valve(i just got it).
speedtrash said:
how much do you guys weigh.
Good point, I edited my original post to include rider and coil specs.

speedtrash said:
and whats with the boost valve? i have the 08 sx with the dhx 4.0. and know nothing of this boost valve(i just got it)
Boost valve for DHX is the adjustable pressure, via a Schrader valve, for the piggyback. It affects ramp-up/bottom out control at end of stroke (very simplified answer).

However, I believe the 08 model has a special OE version of the DHX 4, that doesn't have the Schrader valve option (to adjust the pressure in the chamber), as there are clearance issues on that frame. Therefore, Specialized had a special version w/o the valve created for this SX model.

Also, the settings of the 09/10 may not transfer over directly, as the suspension design changes may affect this (e.g., the 09 suspension is more progressive than the previous model).

Hope that helps.
Update 6 June 2010

toowacky said:
I'm still dialing in my rear suspension on my 09 SXT I. The current coil is a little weak (>35% sag) and I just got a 50lbs heavier spring from my buddy, but haven't installed yet to check it out.

However, just curious what other riders w/ this frame and a appropriately sprung DHX 4.0 coil (or DHX 5.0 coil) are using for their settings (Rebound, ProPedal, Boost Valve).

Undersprung, I was running:

~195-200 lbs rider weight (~175lbs rider + 20-25lbs pack/armor/gear/H2O/etc.)
-600# Fox steel coil
-5 clicks R in from full fast
-6 clicks PP in from full open
-175psi Boost Valve
Current setup:
-200lbs total rider weight (rider+gear)
-650# Fox steel coil (0 preload, just the std 1 turn after contact)
-10 clicks R in from full fast
-0 clicks ProPedal
-130psi Boost Reservoir

The bike has seen about 50% shuttle/ 50% earn-your-turns (fire road climbs). I tried the 650# coil in January, but it felt too firm. That might have been complicated as I also tried a firm spring for the Domain (318 MoCo) the same day. Anyway, I ran the 600# coil pretty much all winter, with a fair amount of sag. Compression was about 2-4 clicks on the Domain, with anywhere between 5-8 clicks ProPedal on the shock (depending on whether it's more fast downhill or more drop/stunt filled) and about 175-200psi in the reservoir.

Last few rides it really seemed like the rear suspension was too soft. Yesterday I ran the current setup and the 650# seemed like it worked much better than previously. Down a fast choppy section, the suspension felt glued and tracked really well. Pedaling was much more efficient, which translated into a snappier bike on the trail. I really only felt a bottom out once, and that was a fast g-out drainage section. Ran 5 out of 10 clicks (more than normal) on the fork to firm up and balance the suspension out, which worked great. Surprisingly, the fork seemed to track just as well as when it was running less compression damping. Overall the Domain has been a smooth, solid fork. Fluids have been changed once, but nothing else done besides a stanchion wipe down post ride.

It's a great feeling when you finally start to find that sweet spot-- completely changed my confidence and riding yesterday. Hope this is helpful to someone.
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I'm 160 lbs without gear. I am running 500# on the dhx4.0 with about four clicks on the rebound. I have about 125 psi. I get somewhere between 25 - 30 % sag. I like it a little plush to match my newly acquired 2011 fox van 36 180mm. Which, by the way, is the bizznezzz. I guess the setup rally depends on the trail you're riding.

Hope this helps.
With 82kg ready to ride I'm running the DHX with 550#, 5R, 4PP and 150psi. The Domain is at 180mm (with a new spring shaft assy), red spring, 2R and 0Compression.

Works AWESOME ;)!
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