[Furball the Mystery Cat]

I got a new bike last week, and I think the shock is defective.

2013 Santa Cruz Tallboy Carbon from competitivecyclist.com (mail order)
Fork: 100mm Fox CTD with Kashima & Trail Adjust
Shock: Fox Float CTD with Kashima & Trail Adjust (165x38mm)

The fork on climb mode feels so stiff that it's almost locked out, but the rear shock on climb mode feels almost as soft as descend mode. I can just barely feel the difference between climb and descend on the shock.

I can't feel any difference between climb and descend on the shock when riding, I only feel the difference when I push down on the seat with my hands.


Is that normal or is the shock defective?

Since fork and shock are both by Fox and have the same travel, should they feel the same on climb mode?

 

[mbell]

Have you set up your sag correctly? When you set up your sag, what "setting" were you on? "C," "T," or "D?"

 

[Furball the Mystery Cat]

Have you set up your sag correctly? When you set up your sag, what "setting" were you on? "C," "T," or "D?"

Okay, I tried setting my sag again. I set the sag with it in the "descend" setting. First tried using my body weight as recommended by Santa Cruz, but that felt like too much sag on steep climbs (even on the "Climb" setting). I added about 30 psi more than my total riding weight and that feels about right on climbs.

Now I do feel the difference between Climb, Trail and Descend. "Climb" still feels too soft. "Climb" on the shock feels about like "trail" on the fork.

 

[Lone Rager]

How does selecting C, T or D affect sag? I thought sag was a function of pressure and not damping.

 

[MotoDane250]

I just built my gf a Santa Cruz Juliana and it came with a Float CTD. The thing feels nearly locked out in climb mode.

 

[keen]

I demo'd a couple VPP Tall Boy's w/ RP23's and I could only feel ProPedal changes while pushing down on the saddle by hand. They were spec'd w/ low compression tune / BV settings.

 

[Furball the Mystery Cat]

Thanks for all the replies. I discovered my shock pump is off by around 50-60 PSI. That was the main problem.

The rear suspension feels petty efficient, so it doesn't need much help from stiff shock settings. With enough air and the right sag, I don't have any problems with pedal bob.

"Climb" on the shock is still way softer than "climb" on the fork, but it is stiff enough to prevent pedal bob.

 

[MTBeing]

The climb on the shock will feel very different than the fork. In fact, I usually ride with my shock in climb b/c I like the pedalling efficiency. Know this though, if the shock develops a squishy feeling, say in a year, that may be that the shock requires a damper service and its normal. Its also $100 and has to be done by an authorized service center or Fox themselves.

Sent from my mountain bike while crashing

 

[ktm520]

It depends on the shock tune. Fox has a couple different springs (two that I've seen) used in the freebleed check valve (propedal). I've played with two of them on a '13 CTD and there is a fairly large difference between climb and trail mode between the two. It also effect descend. I'm guess your shock has the lighter check valve spring. Frames that have a high level of anit-squat will commonly spec the lighter tune because it doesn't need the extra low speed comp damping for good pedaling platform. My SB95 came with the lighter tune. If you send your shock to Fox for a rebuild, they will likely change this for you if you complain about the soft climb mode.

 

[mbell]

Not to bash, but your shock pump really shouldn't have made a difference on your performance on your shock. You should have been setting up the bike based on the sag recommendations. In no way should a defective pump had an impact on this.

What sag do you have set on your fork and your shock?

 

[DethWshBkr]

I don't even go on sag anymore. Proper sag to me makes the bike feel squishy, unresponsive, and blows through the travel too quickly.
I run 100-105 psi front, (proper sag at 90-95 psi) and 250 psi in the rear (proper sag at about 220 psi). This is for my Fuel EX8 29er, Float CTD front and rear.

When I click the rear into climb, I IMMEDIATELY feel every little imperfection of the trail. I can feel the shock blowing off, but the rear feels like a road bike.

Trail mode, I can feel the extra damping, front and rear. Descent mode - feels like I'm riding a marshmallow.

 

[Furball the Mystery Cat]

Not to bash, but your shock pump really shouldn't have made a difference on your performance on your shock. You should have been setting up the bike based on the sag recommendations. In no way should a defective pump had an impact on this.

What sag do you have set on your fork and your shock?

Rear shock only has a 38mm stroke. Suggested sag is 5.7mm 7.6mm. Parts of the frame get in the way and I had trouble getting ruler right next to shock and accurately measuring such a small amount, so I was going by shock air pressure at first. Currently it looks like about 8mm. Feels about right like that.

Fork is not a problem, I'm just going by feel instead of sag on the fork.

 

[mbell]

Let me get this right..... For your fork, you've decided to throw manufacture spec, suggestions, etc out the window and go with "feel." For the rear, you've gone with some direction from manufacturer, but complain about it because it doesn't feel as good as you're fork. I'm sure you're a great guy, but you're an absolute mess when it comes to setting up a bike.
Simple steps:
Get bike and a friend.
Get on bike with all gear and put CTD fork and shock in correct position for "set up."
Bend knees slightly, bend elbows slightly. Get in attack stance and Do NOT put on the brakes AT ALL.
At this point have you friend measure shock "eye to eye," or total shaft exposed. Also have them measure shaft exposed on your fork.
Adjust air pressure to set sag perfectly to spec. Check to see exactly what your bike manufacturer says. It may be different than you think.
Do the math to see where you are, then adjust to accommodate.

Once you do this, you have then have earned the opportunity to complain, etc about how your shock is working, or not working. As long as you aren't doing these things, then he'll knows what you've done to the fork and how it will impact your shock.

Once you've taken good notes on pressures vs performance, them you can make minor adjustments and appreciate the outcome. (Same thing with tires too)

 

[Furball the Mystery Cat]

Let me get this right..... For your fork, you've decided to throw manufacture spec, suggestions, etc out the window and go with "feel." For the rear, you've gone with some direction from manufacturer, but complain about it because it doesn't feel as good as you're fork...

Thanks for all the advice.

My only complaint was about the compression damping on "Climb" on the shock.

Does air pressure or the amount of sag affect how compression damping feels in the "Climb" setting?

 

[DethWshBkr]

Air pressure should NOT affect the C T or D setting on the shock or fork.

Air pressure is your spring. The force pushing the fork/shock apart, and forcing the system to extend. The spring is supposed to be what supports all of our weight, AND absorbs the forces of us sitting on the bikes, and the forces translated through the wheels, frame/fork legs, and into the shock/fork. A spring requires something to slow it down. This is the oil in the fork/shock.
Your CDT system is nothing more than an underwhelming version of compression damping valving. The CTD setting affects how much oil can pass through orifices in the shock/fork. Obviously, the Descent setting opens these valves the WHOLE way open. With minimal oil flow restriction, the shock/fork can compress nearly as fast as the spring (air)can be compressed.
When in Trail mode, the oil passage orifices are essentially restricted, forcing the energy of an impact to force the oil through the orifice, rather than simply to compress the shock/fork air spring. Hense, more damping (more slowing of the speed of compression).
Climb mode, should COMPLETELY close off those oil ports. If the oil cannot pass through those ports, the shock/fork cannot compress. The spring should still bear the weight, but the oil and oil ports are now absorbing a lot of that energy as well. The spring will want to compress, but it cannot, since the oil ports are preventing it from compressing. These systems have a blowoff, which will bypass the closed oil ports, in the event of a large compression impact. This is a good thing, otherwise all of that force directly on the valving would probably destroy the valving.

So, in reality, no amount of air pressure (within design capabilities) should change the fact that you cannot force oil through closed ports. However, if your pressure is too low (too little spring) your shock oil port valving MAY reach the "blow-off" point much sooner than it should, as there is much less spring, which causes more of that force (just sitting on the bike even!) to be placed directly onto the valving. Relying solely on the oil restriction might be overwhelming the "blowoff" valving and forcing it to open.

 

[MTBeing]

I don't even go on sag anymore. Proper sag to me makes the bike feel squishy, unresponsive, and blows through the travel too quickly.
I run 100-105 psi front, (proper sag at 90-95 psi) and 250 psi in the rear (proper sag at about 220 psi). This is for my Fuel EX8 29er, Float CTD front and rear.

When I click the rear into climb, I IMMEDIATELY feel every little imperfection of the trail. I can feel the shock blowing off, but the rear feels like a road bike.

Trail mode, I can feel the extra damping, front and rear. Descent mode - feels like I'm riding a marshmallow.

Ditto on this ^^^. I set up my f/s bike pretty much the same and the pedaling efficiency is much improved. I like it!

 

[cadoretteboat]

4 overhauls later of Fox rear shocks (oil ,o-ring of ifp and recharge. 2 rp23 and 2 ctd) of peoples I ride with including mine. I can tell BY MY experience: it is the lack/low/absence of nitro(air) in the shock. They have to had 250 psi to 300psi. They where between 100psi and 180psi way to low to provide enough ''support'' for the oil to travel with enough volume in the ''system'' (it's the way i see and understand it. I'am no engeneer) Anyway, guest what now? all adjustments works As written in the manual and ''test by the testers'' : Pro-pedal, rebound, and... Tadam my CTD. Clear difference between C T D , even the Trail-Adjust work as it been think for.
My LBS have bikes on the floor whith Fox suspensions not working properly.( I understand why peoples are turning to rockshox and boy they go smooth.)
Same story whith my new front fork FOX float 34 650: Bleed the CTD system and add oil in the legs (air side was almost dry).Got my self a CTD system as publicized on the www. Maybe more on that later. I now have 4 forks to overhaul.
After all that I have had 2 new bike from the same bike two weeks in a row. Thanks FOX

 

[cadoretteboat]

Motocross shop refill shocks. Basic stuff

 

[johnd663]

4 overhauls later of Fox rear shocks (oil ,o-ring of ifp and recharge. 2 rp23 and 2 ctd) of peoples I ride with including mine. I can tell BY MY experience: it is the lack/low/absence of nitro(air) in the shock. They have to had 250 psi to 300psi. They where between 100psi and 180psi way to low to provide enough ''support'' for the oil to travel with enough volume in the ''system'' (it's the way i see and understand it. I'am no engeneer) Anyway, guest what now? all adjustments works As written in the manual and ''test by the testers'' : Pro-pedal, rebound, and... Tadam my CTD. Clear difference between C T D , even the Trail-Adjust work as it been think for.
My LBS have bikes on the floor whith Fox suspensions not working properly.( I understand why peoples are turning to rockshox and boy they go smooth.)
Same story whith my new front fork FOX float 34 650: Bleed the CTD system and add oil in the legs (air side was almost dry).Got my self a CTD system as publicized on the www. Maybe more on that later. I now have 4 forks to overhaul.
After all that I have had 2 new bike from the same bike two weeks in a row. Thanks FOX

Hi,

My forks have just come back from Fox and they are still f@cked. 32mm 29er talas 2014.
I set up my proper sag in 120mm and descend mode. Then in 120mm it basically locks itself out- snaps into climb mode anytime I lift the front wheel. This happens regardless of whether I am in descend or trail mode. If I let out around 20psi it doesnt do it but is then too soft for 100mm. it doesnt do it in 100mm at all but my bike is designed for 120mm. I have a set of X Fusion trace forks which cost 1/3 the price and out perform the last three Fox forks Ive owned. I and tried of being without my bike.

 

[cadoretteboat]

John663. Talas is something different then float as for the spring side. It is the talas that control height adj. And the return force it need to "shock back" rebound.my 2 cent guest is...that you need air in ifp.
With my first fox fox rl 120 way bay in 2006 (talas 1) and later talas have it to) there is a ifp chamber that have to be inflate to x psi in the talas leg. You Need a special needle to do thath but lbs usuly have it and google for. Sorry Cant not post link with my cell .