My Rides

Tuesday, June 9, 2015

Avalanche Downhill Cartridge Upgrade - Fox 36 29 (160mm)

WOW!  Plush on small bumps, and fast bumpy downhills, and really controlled on bigger stuff.

To me, an engineer and "clydesdale" (overweight) rider, I want to maximize the efficiency of my bike.  That means, letting the wheels move out of the way of as many obstacles as possible to preserve as much forward momentum as possible.  Additionally, since my hands support more weight than the typical rider, reducing hand/wrist fatigue is an added benefit - I can go faster on a late ride bumpy downhill...

As I've ridden my stock Fox 36, I've noticed 2 things I expected would be better:

  1. Small bumps at moderate pace produce more handle-bar displacement than I'd expect (not a big deal) - I feel like my Cannondale Lefty DLR 80 (80mm travel) was better at this
  2. Fast downhills over "washboard" or rocky sections (2-3" high) are harsh - on longer rides (>2 hours) I slow to give my hands/wrists a rest, and ultimately carry less speed overall. 
Avalanche Downhill Racing offers a replacement damper cartridge, which offers rider (weight, riding style) tuned damping.  It's best to read how they describe the damper and it's differences to stock, or read similar posts related to motocross shocks (there seem to be more of them).  To me, what it comes down to is:

  • Orifices through which oil can flow are larger, allowing the potential for less damping/resistance as the shock travels.  Meaning:  The shock can be dynamically more compliant (take less force to move it) than stock.
  • Mid to high-speed damping control is more complex - set via shims that flex/bend to control the oil flow through those orifices - and customized to your preferences.  The hydraulic pressure causes them to flex/bend, and the stacking of the shims adjust how they bend - and thus how (dynamically) compliant the fork is at different speeds.  In my case, set to be softer and more "regressive" at high speeds - meaning I get a lot more compliant ride over small to medium bumps.  
When you order from Avalanche you specify your fork model, year, etc., your weight, riding style and riding experience.  As I've pondered this, I think the riding style lets Avalanche target the general shape of your damping vs. speed curve, and your weight and riding experience let them estimate the range of fork speeds you'll experience - so that the tuning "scales" the curve to the range of fork speeds you'll routinely experience.  

First impressions
I've been on 3 rides that include a variety of moderately challenging trails.  While I had set the pressure in the shock to 75-80 psi before (30% sag), I followed the recommendation and set it to 90 psi (22% sag).  Some rides have started with slow rocky climbs.  While not a huge deal, I notice the front is more active - soaking up those small bumps.  I also noticed significantly less dive under braking - in fact I notice the rear shock rebounding (where before I only noticed the front shock activity under braking - they interact, of course).  

When the climb levels out, and I hit some moderate speed rocky sections, it just soaks them up - everything's just more effortless.  The rear, which I've described before as "disappearing", I now notice more.  The UCSC trails have a narrow flow-ey trails with roots.  On root-ey trails, I think I can hear the "blow-off" of the floating valve as I crash over roots.  I find I have to worry a lot less about my line, and can maintain more speed.  I keep the bike on the optimal line, keep my speed up, and the wheel just flows over whatever is there.  

On messy rocky downhills (slow to moderate speed), with rocks 3-6", and drops & steps 8-10", there's just a ton more control.  I can carry a lot more speed in because I'm feeling more in control, and my hands aren't so strained from "just holding on" that I can modulate the brakes, change my line etc.  

The other thing that surprised me was how much better the bike felt on bigger drops 10-14".  I still take these slow - landing the front wheel before the back wheel is over.  With the new damper, the front end seems to compress less (it doesn't - the travel indicators tell me that), but there's less "pitching forward" feeling.  I suspect that the higher low-speed damping is slowing the rate of "pitching forward" so, by the time the front is fully compressed, the whole bike is a bit further down the trail.  This is also noticeable on "whoops" (smooth down then up) - I used to feel the whole front end compress, the tire folding up.  Now it just feels like business as usual - a whole lot less fuss, and more controlled feeling.  

On a very fast rocky downhill, I found myself pedaling through sections I previously just "held on" through.  A whole lot less harshness at the wheel made it up to the handlebars.  Where I'd slow up for a few seconds between harsh sections to shake my hands out, I now sped through to charge into the next rough section.  

Into my 2nd ride, I reduced the rear shock's (Cane Creek DB Inline) high speed compression to minimum, and increased the low-speed and high speed rebound.  On my 3rd ride, I softened up the low-speed compression as well.  On a single track downhill with some small jumps, I noticed the front hard to "lift off" so I reduced rebound damping 1/4 turn.  The tuning sheet with the shock said to decrease low-speed compression 2 clicks to reduce harshness, so I did that to see if it could be even more plush on the fast rocky downhill.  I think it felt a little better (certainly no worse, and no noticed increase to brake dive).  

Thursday, February 19, 2015

The Winner: Specialized Enduro Elite 29

After a month of demo'ing long(er) travel mountain bikes, I've picked a winner for me.  Highlights for me:  29" wheels, over 6" of travel (155mm rear, 160mm front), 1x11 drivetrain, and giant hydraulic disc brakes (200mm front, 180mm rear).  Speaking of giant, look at the size of this 42T rear  cog - about the same size as the 180mm rear brake rotor.

As you can see it's still brand new looking, with warning stickers, and plastic pedals.  I'm planning a more stealth look, so the stickers will come off the fork, and I may even try to spray the frame with transparent black spray paint.

I had debated carbon vs. aluminum frame - wondering if the carbon would be stronger or stiffer.  When I first took a good look at the aluminum frame, I was impressed with how burly it is around the rear shock.

The metal that links the down-tube and top tube is not present on Specialized's lower travel bikes.  It's reassuring that it's so burly - suggesting it's presence on this bike (versus the shorter travel bikes in the Specialized lineup) is more function than styling.

First Ride:

Before the ride, I removed a few stickers, put my Eggbeater pedals on, and swapped the Specialized lock-on grips for some ESI Chunky Silicone grips.  I've had my Cannondale bars wrapped with tape for a few years, and love it - a little cushion, and better grip with sweaty hands.  I purchased these ESI grips (2 years ago) as a next logical step to try, but never put them on the old bike.  I have to say ESI silicone grips are better than wrapped bars.  Real grippy, even when sweat drips down, cushy and comfy.  

I dropped the pressure in the rear shock to 250 psi (down from 270 where the shop set it).  While climbing up it felt a little stiff on square edge rocks, so I backed off high-speed compression 1/2 a turn noticeably better.  I didn't notice any of the "popping" of the front wheel that I noticed on my (most recent) demo of the Santa Cruz Bronson.  

This bike, with this rear shock, really climbs well with the shock in "descend" mode - part of the reason I chose this bike.  About 1/2 way into my ride, I was tired (ran a 10k yesterday), and reached a steeper fire-road climb - just smooth gravel.  I moved the switch to "climb" for this, and it really stiffened things up.  Cane Creek explains their climb mode is superior to other shocks.  To soon for me to comment, but it felt great.  

Before the ride, I set front fork's high-speed compression damping to full soft, and dialed in a few clicks of low-speed compression damping to settle brake dive  After a short descent I set rebound damping to 1-click short of full-soft.  After a steep rocky, rutted, downhill (Zane Gray cutoff) the shock hadn't reached within an inch of full travel, so I backed off the pressure to 80 psi (down from 95 psi set by the shop).  I definitely feel like it is the best fork I've ridden in this travel (Rock Shox Pike, Fox Float 34), but my old Lefty was more plush on smaller bumps on fast downhills.  

The other thing I noticed is how stiff the back end feels.  Definitely less wiggle and flex than other bikes I demo'ed.  So far I don't miss my hardtail for climbing, even on the smooth fire road.

First 50 miles:

I've ridden mostly on my "usual" trails (Wilder Ranch, Santa Cruz).  I really love the way this bike climbs.  I need to get my hard-tail back together (sent the shock for service) to compare, but the Enduro is really great.  

I've had to tighten the derailleur a little (stretch?).  Sharp edge rocks caused a bit of rear "boing" while climbing, so I reduced compression damping 1/2 a turn, and increased rebound damping 1/4 turn.  

On fast, rocky or washboard downhill there was a "braking feeling" in the front as speeds increased.  I took a stab, and set front rebound damping to it's minimum - this seemed to help.  Upon checking the front pressure, it's set to 75psi (I don't know if I reduced it from 80psi, noted above, or if it leaked 5lb).  

I ridden a few of the highly rated downhill trails in the area - something that wouldn't have been possible on the hard-tail.  Extremely rocky downhills at Skeggs Point, and some crazy drops and jumps on UCSC trails.  After these rides, I notice the travel indicators were at max - so with more of this riding, I probably need to up the pressure on the shocks (but I never felt it bottom).  

On the UCSC trails I finally used my dropper seat-post - I don't like it at the bottom though.  All the way down, and I felt less in control of the bike - I like having the nose of the seat between my knees. I also find that I love having a big responsive brake (and suspension keeping the wheel on the ground) in the rear - I find my self scrubbing speed with the rear brake in most circumstances.  This wasn't practical with the hard-tail, and it's 160mm mechanical disc brake.  

There's a little creaking that seemed to be from the cranks, so I tightened the crank-arm bolt, and the bottom-bracket preload.  I still hear a creaking that seems to be in the rear hub.  I'll try tightening the thru-axle next (or maybe the cassette nut needs to be tightened).

The last complaint is the saddle - a little padding over hard plastic is hard to get used to after 4 years on Brooks saddles.  I'm going to try the Brooks on this bike, but I may go with something else.  The idea of a flexing saddle that breaks in near the sit-bones seems to have caught on.  Ergon has a nice saddle, and Koobi will custom make a saddle based on your weight, riding style, etc.  I had considered Brooks C17 (rubber and fabric), but people say it's "grippy", which wouldn't be good for a  mountain bike.

Overall, I love this bike.  I can't really imagine riding my hard-tail on anything other than a gravel road.

2nd 50 Miles:

I pumped the front shock up to 80 psi, and for a long trail ride it was definitely too stiff - didn't seem to soak up the small stuff.  75 psi is the right setting for me, at least until I send it off to Avalanche Downhill.  I checked the rear shock, and restored it to 250 psi - felt about right.

I felt like the Specialized Henge Comp saddle was a bit too firm under my sit bones.  I'm not wanting to worry about Brooks leather on this bike, and I've had good luck with Ergon products in the past, so I bought an Ergon SME3 Pro saddle.  The first ride on it was a long climb up single-track and fire road, and it felt great.  Didn't "disappear" as much as a broken in Brooks, but was barely noticeable at the end.  This is where the Specialized fell-short - sharp pain in the sit-bones at the end of climbs.

I also changed the grips, again.  The ESI Chunky grips were great, but I saw they now make an Extra Chunky, so I ordered and installed a set of these.  I definitely like them more on this bike - I can squeeze hard on uphills, and I feel like they soak up a bit more on downhills.  The yellow chunkys went on the old hard-tail (which now pulls a single-wheeled trailer).

I've had the tires at 28 psi in the front, and 35 psi in the rear.  The rear feels about right, but I think the front could be softer.  I may try 24 psi next ride.  

Monday, January 19, 2015

Demo'ing Long Travel 29ers (and some 650B)

A few things have motivated wanting to retire (probably) my short travel (80mm) 29er hard-tail for long(er) travel full suspension bike:

  1. In California, compared to the Michigan and Illinois, there's a lot more elevation change for most of my rides.  More sustained downhill time leads to more potential downhill speed.  Although the trails aren't that much more bumpy, rocky or root-ey there are longer stretches going down...
  2. So far, I haven't found the same sort of cross-country and/or gravel road races that I found in the midwest.  Most of my riding is adventure or training (for road bike leg of a triathlon).  
  3. It's just more comfy and forgiving.  A little too much speed over a drop - no problem.  Miss the perfect line and hit a rut - no problem.
  4. I love going downhill.  I'm pretty good at it - picking out a good line, keeping off the brakes, keeping my weight back, and just flowing with the trail.

How much travel? 

 I've been thinking about this for a couple of years.  At first I was thinking 100mm front and back would probably be nice.  I'd still have a lighter, cross country bike.  In engineering terms, though that's only 2dB (25%) more travel - an incremental improvement, but not significant for a "full product refresh".  120mm would be solidly over 3dB (more than 40% increase), but can I really carry significantly more speed, or notice a huge difference...

6dB is significant - 2X the travel.  

A few years ago (2011) I rode an Ellsworth Epiphany with 5.5" travel.  The ride included a 3 mile desert rocky downhill.  It just seemed to float down the trail.  I thought about this the other day, as I bombed down a rocky downhill with my wrists taking a pounding - if I had 2X the travel, my front suspension could be set 1/2 as stiff, and I'd barely be feeling anything.  So, I'm starting at 140-160mm (~5.5-6").  

What wheels?  

I've had no issues with 29" wheels.  When the trail is bumpy they're like having an extra inch of travel, and when the trial opens up they're faster cross country.  The first bike I demo'ed was a 650B (27.5er), with 2.3" tires.  

They look nearly as big as big at the perimeter as my 29" wheels with 2.1" tires, and I can't say I could feel a difference (too many other differences), so I'm open to 27.5, but will target a 29er.

First Demo:  Specialized Enduro Expert Carbon 650B & 29er

(noted features are not meant to be complete, but are differentiators that I'm focused on)
  • 165mm rear travel (155mm for 29er version)
    • Cane Creek DB Inline Shock
  • 160mm front travel 
    • Rock Shox Pike
  • SRAM XO 1x11drivetrain with 34T (30T 29er) front ring and 42T biggest rear ring

The Front:

I didn't feel quiet the "floating" that I remember from the Ellsworth from a few years ago.  The front shock felt like it had a little "stiction", and didn't feel as plush as I'd like.  I've read a few reviews where the reviewer mentions how great a Cannonade Lefty feels compared to what they typically ride - mentioning a lack of stiction...  When I finished the ride, I noted that the shop had set up the shock at about 10% sag.  I reset the sag to 30%, and did a few A-B comparison spins around the house (comparing the Specialized to my Cannondale).  The Rock Shox felt much better, but the Lefty does seem to be a little more responsive to the small stuff.  What I take away, is that if I buy a non-Cannondale, I will budget for a higher-end shock (assuming the larger diameter, more expensive shocks float a bit more over the small fast stuff).

Update (29er)
Today, I demo'ed the 29er version of this bike.  The shop set the sag on the front fork at about 20% (110 psi).  Out on the trail I dialed back the rebound damping, and left the air pressure at 110 psi until I did a downhill section.  At the bottom of the downhill, I noticed that the shock hadn't reached within an inch of full travel.  So, as with other demos, I backed off the pressure to about 90 psi (30% sag).  Much better!

As I turned around, and started heading downhill, this thing really floated.  I went through choppy and rocky sections much faster than in previous rides.  I stopped after it got a bit jarring, and set the rebound damping to minimum.  Much better for descending fast...  Big wheels, a plush shock and lots of travel is the ticket!

I do think I will order a cartridge upgrade from Avalanche Downhill Racing.  They sell a replacement damper cartridge that gives speed sensitive damping, with valving, etc. optimized for rider weight and riding style.

The Rear:

The rear felt great - maybe a little over-damped.  The bike shop warned me that the rear shock setup was complex, so I left it as it was.  You read marketing stuff, and technical comparisons of rear suspension types, and worry about climbing efficiency (bob), and behavior under braking.  I didn't notice anything I'd object to.  Just seemed to do it's job, with no ill effects - I assume that's the case for all of today's rear suspensions (though I do feel like Ellsworth has a suspension story that resonates most with me).

Update (29er)
The 29er felt a bit underdamped (popping up on bumps while climbing).  This time I wasn't shy about adjusting the shock.  I increased low-speed rebound damping, and decreased low-speed compression damping.  After a downhill section, I noticed I'd only used about 2/3 of the travel, so I decreased the pressure from 290 psi to about 260 psi.  Now there was a bit of that over damped feeling while climbing.  Not enough to make me stop and change it, but it seemed clear that the adjustability of the Cane Creek shock would let me dial it in.

The rest:

1x11 drivetrain is not something that I would have planned for my bike.  I'm a heavy rider, and I routinely use my 22T - 34T (front - rear) combination (0.65 ratio).  First, I had no idea that they have rear gears with 42T.  Today's ride was mostly short duration, and not very steep climbs.  I could tell that the 34T - 42T combo wouldn't get me up some hills.  I understand that you can get 28T front rings (which would get me roughly the granny ratio I have now).  Given that, the simplicity and low clutter make a 1x drivetrain appealing.  

Update (29er)
The 29er has a 30T front ring, making the low ratio 0.71.  This worked pretty well.  The climb is now very familiar - I walked all of the same sections of trails I walk on any other bike.  Going down I never used the highest gear.  Since the first ride, I learned that by going to a direct mount chainring, like these from Wolf Tooth.  They have as few as 26T front rings.  

This bike had hydraulic brakes (180mm front & rear).  I love these.  I've convinced myself that my current bike's Avid BB5 and BB7 cable brakes are "just fine."  They are, but these hydraulic brakes are great.  I had to adjust the reach to be less "touchy" where my fingers just grabbed them (I adjusted the reach closer).  

The 29er was not available for demo, so I took the 650B (27.5).  As mentioned above, they don't look much smaller than my, admittedly narrower, 29" tires.  If you google 29 vs 650B then you see a more significant difference.  So, if I can keep all else equal, I'll stick with a 29er.

Since my last bike purchase, quick release axles have gone out of fashion, and rear hubs have gotten wider.  I'm all in favor.  I can't say I notice the lack of stiffness while riding, if I plop my bike down it goes "twang" and I can see a lot of side to side shimmy as it "rings down" (picture a tuning fork).  I assume this accounts for some energy loss.  This had the 15mm thru axle in the front, and something similar in the back.  When I plop it down, it feels solid, and riding it felt as "stiff" as my hard-tail.

Summary:  Specialized Enduro Expert Carbon 650B

Love the travel, probably perfect as a 29er, with the front shock dialed in, and a 26T front derailleur.

Update (29er)
Yep, perfect as a 29er.  I could set it plusher than the Trek or Santa Cruz, and float on the fast downhills, and still have enough travel for the slower, bigger drop sections.  

Trek Remedy 9.8 27.5 (again, no 29er available)

  • 140mm rear travel (same for 29er version)
    • Fox .. Float, DRCV, RE:aktiv, CTD
  • 140mm front travel 
    • Fox .. Float 34, CTD, FIT damper (80 lb, final pressure)
  • Shimano XT 2x10 drivetrain with 24:38T front ring and 36T biggest rear ring
This bike felt more "normal" and upright, like my hard-tail.  The Trek has 67.5 deg. head tube and seat tube angles (in "Low" geometry position").  The Specialized had a 65.5 deg. head tube and a 74.5 deg. (effective) seat tube angle.  The Specialized felt tall in the front and I think I know what the term "slack" means.  The 160mm travel Trek Slash would have been far more comparable bike to the Specialized (if the target were 27.5).

The Front:

At the shop I paid attention to the sag - it was set to around 20-30%.  I ended up forgetting to stuff my shock pump in my pocket, but I did pay attention of the first few minutes of the ride.  It felt "sticky" so I dialed the rebound to the minimum rebound damping ("full soft" to use the lingo) - MUCH BETTER.  As I rode, I kept pushing the o-ring (peak travel indicator) down the stanchion.  On fast rutted trail, with the occasional 3-4" step or drop I was using most of the travel.  Over slow descent drops, all of the travel.  I would have liked a little softer, so I think I'm saying I'd like a little more travel (or those 29" wheels).

The Rear:

I think the pressure was set right, but it had that same over-damped feel as the Specialized.  This shock was easy to adjust (not that I prefer that, it just made it easy to play with), so I dialed the rebound damping to the minimum (full soft).  As I climbed, as I'd hit a bump, I'd "boing" up on the rebound, so I kept clicking in a bit more rebound until there was only a tiny bit of overshoot ("boing") - that felt right to me.  In fast descents, where I lift out of the saddle, the damping felt right (I think if it's critically damped for seated, it's over damped for standing).

The shock has CTD (climb, trail, descend) settings, and the shop encouraged I keep it in  trail.  I tried trail for climbing, and on flat ground, but I just kept switching it back to descend.  I can't say I noticed, or had any complaints with only 140mm rear travel.  That may be because of the DRCV (secondary volume that opens at high travel), or RE:aktiv (Penske regressive damping that makes it stiff on slow stuff, but soft on fast stuff).  Regressive damping makes a lot of sense to me.  I've been looking at Koni FSD (Frequency Selective Damping) shocks for my car - the track tests of those indicate faster lap times.

The rest:

This bike had XT drivetrain, with an familiar front derailleur.  With a 24:36 (0.67) low gear, it climbed nicely.  I did use the big front ring, bit not the highest gears (so maybe a 1x11 with a 26-28 tooth front gear would be fine).


The bike used Shimano XT components.  The shifters felt a little cheap and plastic-ey compared to the SRAM X0 stuff (or the old SRAM X7 on my old bike).

Summary Trek Remedy 9.8 27.5:

I think this bike would be nearly perfect, with 29" wheels and more travel in the front.  

Upon return, I told the manager at Epicenter Cycling this.  He proceeded to show me his personal ride, which used a Fox Float 36 with 150mm travel.  The axle to crown height made for identical geometry to the stock bike.  A couple of light pushes on the handlebars seemed to indicate the small bump compliance would be better.  They explained 160mm of travel would void the warranty, as it would change the geometry - possibly enough to amplify frame stresses...  

Santa Cruz Tallboy LTc (c for carbon.  Finally a 29er!)

  • 135mm rear travel
    • Fox Float CTD (240 lb final pressure)
  • 140mm front travel 
    • Fox Float 34 CTD (80 lb final pressure)
  • Shimano XT 2x10 drivetrain with 22:34T front ring and 34T biggest rear ring
This bike also felt more "normal" and upright.  They explained it was last year's demo, and there seemed to be a few creaks and slips of the chain.

The Front:

They set me up at about 30% sag, and the rebound damping was pretty high.  Also, as they exercised the suspension to check sag, it felt sticky and "grungy" (not really smooth).  This was likely due to a year of demo.  What it tells me is that if I want good life out of a shock, the stronger Rock Shox Pike or Fox Float 36 would be a better choice.

Again, on the trail, I immediately backed off the rebound damping completely.  On the same climb (as yesterday, with the Trek), square edge rocks felt round.  The fork had about 30 more pounds of air (110b), and it felt more old and worn, so I attribute this completely to the 29" wheels.

For this ride, I took the "Enchanted Loop" trail, which drops into the redwoods, with rocks and roots, and over a few 8-10" drops.  On the first drop, the front end rebounded a lot.  I dialed in about 1/3 of the available rebound damping - much better.

The Rear:

The rear felt simple.  It didn't really disappear.  It was fine for climbing, and for descending, but I was always aware that it needed a little something.  I ended up dropping the pressure to 240 lb (from 270).  I did find that setting it to climb for climbing, and descend he rest of the time was nice, although I would have preferred to be able to add a little rebound damping and leave it in descend.  A better rear shock would have made this bike better.

After riding the Trek with ABP (Active Braking Pivot) I experimented with braking on fast bumpy descents.  I think I could feel different, but it didn't seem huge.

The rest:

Another XT drivetrain.  With a 22:34 (0.65) low gear.  Not much else to mention.

Summary Santa Cruz Tallboy LTc (carbon):

Nothing special.  Felt a bit outdated.  

Santa Cruz Bronson C 

  • 150mm rear travel
    • Fox Float CTD (250 lb final pressure)
  • 150mm front travel 
    • Rock Shox Pike (85 lb final pressure)
  • SRAM 1x11 drivetrain 
This really isn't a candidate - I sent my Cannonade shock in for service, and Santa Cruz has a great factory demo program - only $20 for 4 hours (+ a free t-shirt), and had a bike for me as a "walk in".  Since there are so many more choices (and more used available on ebay) for 150mm-160mm 650b (27.5") bikes, I did want to ride one more to confirm my decision to get the Specialized.

This bike, unlike the others, always seemed to pop the front wheel while climbing.  Usually it wasn't a problem, but in one instance I "failed" on a technical section because the front popped.  I don't understand what caused this, but I suspect some combination of geometry and rear end behavior (maybe needed more slow rebound damping).  I caught up to a guy on the trail on a Cannonade Jekyll, asked him how he liked it, and he commented that it always pops the front wheel climbing...  So, not unique to this bike, but annoying.  Giving this some thought, I would expect the Specialized to suffer from this, with it's shorter chain stays, but perhaps that "over damped" feeling was damping dialed in to keep things settled.

The Front:

Was happy to see a Pike on this bike - I've come to expect a better experience with this shock.  I dropped the pressure to 95lb at the beginning of the ride, but dropped it to 85lb after some short descents.  I never touched the rebound damping, which was set nearly 1/2 way through the range.  A few times it felt like it wasn't soaking up the small stuff on flat ground...  

The Rear:

Similar to the SC Tallboy LT, the rear kind of felt ever-present.  I dropped the pressure immediately to 250 lb, based on past experience.  I did use all 3 settings during my ride - descend wherever possible (faster flat sections, rocky climbing), trail when climbing bumpy single-track, and climb on some steep, but smooth sections.  I could see how this may seem sufficient, but the rear shocks on the Trek and the Specialized could just be left alone (in descend), and not provide sufficient reason to touch it...

I also seemed to notice the rear end twisting and flexing.  Glancing down at the linkages, one can see that they're less widely spaced than those on the Specialized (which felt stiff).

Summary Santa Cruz Bronson C (carbon):

Didn't like the front end popping.  Confirms that I need this travel on a 29er.

Some Notes:

Jan. 24
After riding the Trek with the regressive damping, I searched for "Rock Shox Pike Upgrade" and read on pinkbike that Push Industries offers and upgrade/rebuild that adds frequency dependent damping, and optimizes the valving for the rider's weight.  This sounds ideal.  There seem to be several companies that rebuild/upgrade forks and shocks.

Jan. 25
I've ridden 2 ~140mm travel bikes.  That amount of travel seems fine for the loops I've discovered so far, and would consider the caliber of ride I usually enjoy.  I don't see myself ever falling in love with "downhill" riding - big drops, plowing through rock gardens.  I don't mind a bit of that, but I also like climbing, and fast descending.  So, after a few demos of 5-6" travel bikes, I'm not feeling like I need 8".  However, I do feel like 130-140mm doesn't leave much room to grow - I would like the bike to support me in trying out a few gnarly trails, or saving my butt in unfamiliar terrain without the feeling that the bike is what's holding me back.

I think I'm realizing that the Specialized Enduro 29er is the bike for me.  I chalk up any negative first impressions to inexperience, the front fork being set stiff (and never fooling with damping), and lack of 29" wheels.  On that demo ride, the sag was set to 10%, or less than 1".  Had it been set to 30%, the front would have been over an inch lower, and softer.  The rear suspension felt great, the Cane Creek DB Air Inline shock is extremely adjustable, and the Rock Shox Pike is the fork to have for enduro riding.

The 1x11 drivetrain is cool (simple), and it just seems Specialized has put together the particular combination of features I'm looking for.

Feb. 1
The Specialized Enduro 29er (with the front sag @ 20-30%) didn't feel "slack".  The long travel plus 29" wheels was awesome.