Back to the Trance

I got to take theTrance out again today. We went to The Newlight Trails A great mixture of fun and tough. Lots of short rooted climbs for an old man(That would be me) to tackle and I am clapped out(Not a reference to an STD). So this, the Trance story, may run to a three parter.
Back to setting up the suspension. I know this is not specific to the Trance, but I get asked a lot about doing set up so this seemed as good a time as any to include it, and it applies to all suspension setup. Yesterday I talked about setting sag and setting rebound. Today we will go into compression damping.

By the way the controlled action of the suspension is damping, not dampening. Dampening happens when you wash your bike. And quit putting a "U" in stanchion. One more, don't pout when you find out you cannot pump up your shock with a floor pump.

Back to compression. This is the controlled motion of fork in the compressing (when you hit a bump) direction. Most forks/shocks do not have adjustable compression. If you are one of the lucky few, you want to set it up so that the fork/shock reaches full compression on the hardest thing you hit. This makes set up easy for a course but harder for general riding. However, most people ride in the same places all the time so you should have a good idea of where the big boys are. I wish that more suspension had this adjustment because, if you are fully compressing the fork, often the only fix is to increase the preload(More air or bigger spring). Even upping the weight of fork oil does not help much(It is good if you need to increase rebound more than the adjustment allows) The big problem with increasing spring rate to solve a compression problem is that it reduces your sag. You don't want to reduce sag much because this is what helps keep the wheel planted. The suspension needs to be compressed a little so when you go over a hole or other drop the wheel can quickly move into it and retain grip. This also reduces the jarring on the rider.
In the case of the shock on this bike, a Fox Float RP23, there is also a Propedal lever with three settings. What this does is increase the initial compression damping. This helps when you ride mixed trail with rough and smooth sections. You can get out of the saddle and sprint with minimal rear suspension movement but when you hit a big root or rock it will move past this high damping and into the normal rate. The three settings let you pick just how hard a hit it takes to get out of Propedal. The fork, a Fox 32 F120RL, has a similar feature with its lock out, but there is only one setting.

So, I set my bike up based on my 180 pound weight(I am trying to correct this by growing another two inches, which reminds me of a Richard Pryor joke) 90psi in the fork and 180psi in the shock. A sag check showed me in the ballpark. I dropped the pressure in the shock to increase sag a touch(This later proved to be a mistake as stiction was screwing up the sag a bit) Then I increased the air pressure a little in the fork. This also was a little bit of a problem but I had test ridden down a stair case and it felt to soft(Have you been paying attention? How would I fix this? That is right more compression damping, however that knob is missing from this bike) Turns out this made the fork a little to stiff and the sensation I was feeling, being tossed over the bars, was better alleviated by increasing the rebound on the shock. This slowed the rear down so it did not feel so much like it was catapulting me. Unfortunately I did not get to play with the pressure for the actual ride as my pump was resting securely in the tool box, where it could not be stolen(or used).
Alright, I have to call it it a night and fall out before I fall down. To paraphrase Bullwinkle, "Tomorrow, for sure"

First ride with the Trance

Finally. After waiting for two months to get the bike and a week and a half to get a chance to ride it, we went out. I thought it was going to be a no-go as there was a customer taking their sweet time buying a bike and a half dozen people standing in bike gear and talking about how great it would be to get to go for a ride together for the first time in a while, if it did not get dark to soon, had no observable effect. But that column is for another day.

So. The Trance X 0. I got this bike a little over a week ago. No chance to ride due to weather and other obligations. I spent some time setting up the suspension. Good thing I had time, because the the Fox instruction is pretty much limited to, "You need 15-20% sag" Yeah, thanks. How about some freaking starting numbers. I don't expect Fox to give a word for word explanation of the setup with full color photos and a roll out mat of test obstacles. But how about a damn starting point. An, " If you weigh this, try this pressure for a start point" You are not going to find that ANYWHERE in Fox setup. Thank goodness you have me. Fox wants you to look for specific a sag measurement. So to do it their way you will need to increase the shock/fork pressure in one pound increments until you get the number you are looking for. I, however, have some ball park numbers, that will get you started and they are easy to remember. For the fork start with half your body weight. I have tried this with both Float and Talas forks to good effect.
For the shock. This is for the air sprung Float shocks, use body weight(Your body weight, I get to ask women how much they weigh all the time. Sag does not lie, sag is the only one not lying)
These numbers are only a starting point. You will still need to tune for the right sag. Around 15% for cross country, 20% for fun riding(The best kind), and up to 25% for freeride or downhill(This is usually only with really long travel bikes)
Another thing to keep in mind when you set up your new suspension is that there is stiction with a new bike because everything is not broken in yet. You can try whispering gently in to your bikes ear but stiction will remain a problem(for setup) until the suspension breaks in.
Now set up your rebound(and compression if it is adjustable) I set my rebound at the half way point and tune from there. I do this based on how the suspension feels to me. The easiest way to describe it is to bouncy(or not bouncy enough, this is packing up) If the bike feels bouncy then you need more rebound. Rebound is the return speed of the fork after being compressed, just to clarify that. I might have been a little quick and as I get better at this, I hope to lay out this stuff a little better. If the susoension keeps getting shorter after running over a set of stutter bumps(Around here that is an old potato field), then you need to reduce your rebound.
Tomorrow I will get into the compresion setup, more on rebound, sag, and how the bike actually worked. The big plus for my contrived suspense is one more day of riding to get my thoughts together and play with the setup.