[sethimus]

That's is really great of Trek to provide that information. But notice how all they give you is # of clicks. Granted, that is a very easy to understand, but thinking in terms of # of clicks is not translatable across different frame, shocks or rider weights. # of clicks is somewhat arbitrary. If instead Trek said, start with click 0, then bounce your bike and increase clicks until your bounces uses 75% of travel. For a 140lb rider that may be 3 clicks. For a 200lbs rider that may be 10 clicks, but this way, if you're thinking in terms of 75% bounce sag, you now have a measurements that will translate to different shocks. Say you swap out for a shock or fork not listed on Trek's manual. # of clicks doesn't mean a ___ thing! Who knows what the equivalent # of clicks is between one shock and another for the same rider? But if you're thinking in terms of % bounce sag it's not an issue. Maybe on your new shock, 6 clicks of LSC provides the same bounce sag as 2 clicks on your previous shock.

and how will you be sure that everyone "bounces" his bike in the same way and with the same force? just take a kitchen scale and try to press down your finger with the same force say 10 times without looking at the scale, and someone else tells you the result...

 

[DirtyMartini]

That's a great question!
The short answer is I don't think it matters. In my original post I started to outline why this exact question doesn't matter, but it got even longer! What I posted was the short version.

All that matters that the same person bounces with same amount of force.
Not everyone will bounce with the same force. A 200lb rider will bounce with more force than a 140lb rider, and thus the 200lb rider will need more LSC for equivalent performance.

Now here's the tricky part. Say you have two 180lb riders. One with strong legs and one with weak legs. The stronger rider can bounce with more force, and thus want more LSC IF (and only if) they plan on using their additional strength by taking on larger impacts (e.g. larger drops). However, if this stronger rider is going to ride below their body's capability, then they may want less LSC (less bounce sag) for a more supple ride. In this case it IS about the rider's personal preference.

This is all based on the assumption (correctly I think) that the stronger you can bounce (with concentric muscle contractions) the greater impact you can absorb (eccentric muscle contractions). So two riders of equal weight and difference strength would have different LSC settings (but perhaps the same bounce sag). The stronger rider's setting is for more aggressive riding (since he's stronger and can handle it) and the weaker rider is for less aggressive riding (since he's weaker). Again, if the stronger rider want to do less aggressive riding than he can physically handle, the he just back off the LSC to comfort.

and how will you be sure that everyone "bounces" his bike in the same way and with the same force? just take a kitchen scale and try to press down your finger with the same force say 10 times without looking at the scale, and someone else tells you the result...

 

[norbar]

That's is really great of Trek to provide that information. But notice how all they give you is # of clicks. Granted, that is a very easy to understand, but thinking in terms of # of clicks is not translatable across different frame, shocks or rider weights. # of clicks is somewhat arbitrary. If instead Trek said, start with click 0, then bounce your bike and increase clicks until your bounces uses 75% of travel. For a 140lb rider that may be 3 clicks. For a 200lbs rider that may be 10 clicks, but this way, if you're thinking in terms of 75% bounce sag, you now have a measurements that will translate to different shocks. Say you swap out for a shock or fork not listed on Trek's manual. # of clicks doesn't mean a ___ thing! Who knows what the equivalent # of clicks is between one shock and another for the same rider? But if you're thinking in terms of % bounce sag it's not an issue. Maybe on your new shock, 6 clicks of LSC provides the same bounce sag as 2 clicks on your previous shock.

What you suggesting seems harder than riding and adjusting it on the trail. Not to mention you still have to adjust the HSC and you can't do that in the parking lot.

 

[DirtyMartini]

Good question. My thinking is that you would set your LSC in the parking lot according to bounce sag as a starting point. Then ride and adjust as you go to fine tune it. Then when you get back to the parking lot after the ride, take your bounce measurement again (at the LSC setting you fine turned on the trail). Record this number as this number represents the EFFECTIVE lsc setting you happen to like. Then if you replace the shock, or get a different frame, you can start by tuning with the same bounce sag setting you determined on your previous bike (whatever # of clicks that may be). And then perhaps fine tune a little on the trail again with your new bike.

It's just about having an objective measurement that is translatable between shocks and frame for a given rider. Your personal favorite bounce sag is not written in stone, and you may like it a little different between one frame and another, but at least you have a good starting reference point.

We're already dealing these same complications with sag. You may like more sag on a DW bike, but more sag on a FSR. But you still have an objective measurement for comparing and constrasting, which is helpful.

What you suggesting seems harder than riding and adjusting it on the trail. Not to mention you still have to adjust the HSC and you can't do that in the parking lot.

 

[92SE-R]

So did you ever get your 5h element installed?

 

[DirtyMartini]

Ya, I did get it installed, but only by using some small generic right spacers on the upper hardware. The shock is okay (not great) on a 6point with min LSC and HSC settings, maximum air chamber volume and min psi, but is still noticeably over damped for such a low leverage design. Getting close to sending it Craig at avy.

So did you ever get your 5h element installed?

 

[DirtyMartini]

Last time I checked most custom tuners asked you about your preference

My experience with tuners and from what I've read about Push and Avy, is that they ask you your riding STYLE preferences: what do you like? Big drops, slow steep chunky technical, FR, trail, climbing, etc.

I could be wrong, but I don't think tuners tend ask for your preferences in terms of how much LSC you like, how much HSC you like or how much rebound you like. I'm sure if you specificy that you like bike with very low rebound they can make sure that's what you get. But my understanding is that they tune according to 1) weight 2) frame 3) shock and 4) the type of riding you do.

 

[staike]

Ya, I did get it installed, but only by using some small generic right spacers on the upper hardware. The shock is okay (not great) on a 6point with min LSC and HSC settings, maximum air chamber volume and min psi, but is still noticeably over damped for such a low leverage design. Getting close to sending it Craig at avy.

I've never understood the term "overdamped". Does that mean too much or too little compression? I have a Roco Air WC on my 7point and the bike wallows a LOT more, like as it have far less LSC than the stock DHX 3.0. Performs 100 times better on the trails though.

 

[Steve M]

I've never understood the term "overdamped". Does that mean too much or too little compression? I have a Roco Air WC on my 7point and the bike wallows a LOT more, like as it have far less LSC than the stock DHX 3.0. Performs 100 times better on the trails though.

Overdamped = too much damping.

 

[Whoops]

That's is really great of Trek to provide that information. But notice how all they give you is # of clicks. Granted, that is a very easy to understand, but thinking in terms of # of clicks is not translatable across different frame, shocks or rider weights. # of clicks is somewhat arbitrary. If instead Trek said, start with click 0, then bounce your bike and increase clicks until your bounces uses 75% of travel. For a 140lb rider that may be 3 clicks. For a 200lbs rider that may be 10 clicks, but this way, if you're thinking in terms of 75% bounce sag, you now have a measurements that will translate to different shocks. Say you swap out for a shock or fork not listed on Trek's manual. # of clicks doesn't mean a ___ thing! Who knows what the equivalent # of clicks is between one shock and another for the same rider? But if you're thinking in terms of % bounce sag it's not an issue. Maybe on your new shock, 6 clicks of LSC provides the same bounce sag as 2 clicks on your previous shock.

You're assuming the factory can make consistent shocks/forks... or have some end-of-line calibration capability?

 

[jrewing]

I always wonder what the very elite/pro riders think when they see posts like this?!
" Dunno bro I just send it "

Just send it... 2 or 3 clicks won't win it for you. Nor will 200 grams. Fitness and balls might.

 

[Steve M]

I always wonder what the very elite/pro riders think when they see posts like this?!
" Dunno bro I just send it "

Just send it... 2 or 3 clicks won't win it for you. Nor will 200 grams. Fitness and balls might.

Actually I have undertaken timed testing, averaged out over a number of runs using small-sample statistical analysis methods, that shows with a very high degree of confidence that suspension setup CAN make a measurable difference to your times. In one situation, two clicks on the rebound adjuster made about 0.8 seconds difference in a minute (over 4 minutes, means you could potentially save 3.2 seconds with a better rebound setting!). If you're racing at the top level and you're not anal about every single facet of your riding, then yeah, you might actually be losing races because your setup isn't good enough. The same applies to cockpit setup, brake setup, gearing, tyre pressure, tyre selection - you name it, it has an effect. Just because nobody's measured it before doesn't mean the effect isn't measurable either!

However, I do understand what you're trying to say, and yes of course skill and fitness will play a far bigger part in how fast you are, than how well your bike's set up. That much is obvious to anyone.

 

[weedkilla]

Ok, I can follow the idea of tuning suspension to absorb bumps, BUT I have on several different bikes needed to compromise my suspension tuning to balance other factors. Some bikes had way too much LSC in the rear to make it pedal ok, others too much LSC in the fork to compensate for a steep HA, too short in the wheelbase and I need more HSR in the rear...... The list goes on, I think we all have a "base" tune, for some it is however the bike comes, for others a bounce in the carpark and a tweak of the adjusters. This is then taken to the track and sometimes I end up a long way from what seemed like a good idea in the carpark.
Where I'm really lost on why there would be a standard for tuning suspension is this - my body position on the bike is completely different to someone else. I cant imagine (for example) taking the shocks out of a Porsche 911 and putting them in a BMW M3. The front/rear balance of my combined bike and rider could be as different as that or more when compared to another rider of the same height and weight, even if it was measured the same when we stood statically in the attack position.

 

[DirtyMartini]

You're assuming the factory can make consistent shocks/forks... or have some end-of-line calibration capability?

Actually, just the opposite. In fact, it's Trek (in this example) that is assuming they can make consistent shocks/forks. This is assumption is implied by them suggesting suspension setup in terms of # of clicks. Say two 180lb riders with the same bike and the same shock are setting up their bike according to Trek's directions and they both set their shocks to 5 clicks of LSC. If their shocks where not manufactored consistently, then maybe of should have 5 clicks and the other should have 7 clicks to obtain the same level of LSC. The easiest way to test this would be through testing "bounce sag" since "bounce sag" measures the net effect of LSC on your bike.
The point is "bounce sag" accommodates for manufacturing inconsistencies; # of clicks does not.

 

[DirtyMartini]

Weedkilla:

Looks like there's a little miscommunication here. It's not being suggested that the parking lot bounce sag test has any immediate QUALITATIVE function. That is, you're not looking for what "feels good" in the parking lot during a bounce sag test. The only purpose of the bounce sag test is to have an easy and consistent measurement of how much your LSC setting is effecting your bike.

If you change out shock or fork, it will be helpful to have your bounce sag measurement handy for setting up your new component because the bounce sag # represents how much LSC YOU like on THAT frame.

If you change frames altogether, it would still be useful to carry over your bounce sag number has a starting point. Then fine tune as you ride the trail, then remeasure your bounce sag in the parking lot afterwards, and that is your new number for your new frame. If the frames are similar (e.g. both FR) I doubt your desired bounce sag # will be massively different between the two.

For a different rider altogether, the bounce sag setting becomes a little more of a rough starting estimate (just like spring sag).

Bounce sag is not about a standardized SETTING, it's about a standardized LSC net effect, just like spring sag. All the complications of different rider weights, frame geometry, leverage curves, riding style, body position, personal preference, etc already exist when setting up your spring sag and we happily suggest and talk about sag settings and make recommendations.

Sure, on the same bike, with the same shock, one person may like their spring sag at 31% and another may prefer 28%, and that fine, that's personal preference, but at least we have some idea of approximatley where spring sag should be set. All I'm suggesting is that do the same thing, but with LSC. One person may prefer 80% bounce sag and another may prefer 70%, but it's all within an appropriate standardized range. Just like spring sag.

 

[Vrock]

Actually, just the opposite. In fact, it's Trek (in this example) that is assuming they can make consistent shocks/forks. This is assumption is implied by them suggesting suspension setup in terms of # of clicks. Say two 180lb riders with the same bike and the same shock are setting up their bike according to Trek's directions and they both set their shocks to 5 clicks of LSC. If their shocks where not manufactored consistently, then maybe of should have 5 clicks and the other should have 7 clicks to obtain the same level of LSC. The easiest way to test this would be through testing "bounce sag" since "bounce sag" measures the net effect of LSC on your bike.
The point is "bounce sag" accommodates for manufacturing inconsistencies; # of clicks does not.

Cmon, don't bash on Trek. I've checked the setup guide and it's a good start. I wish everyone else would give that kind of info or even a litte bit more. Shocks can be inconsistent but I don't think there is too much dispersion.

 

[Udi]

Nice idea in theory, but hardly practical.

Look at our existing sag measurement - does anyone even really know how it works?
- Is it taken when seated, or standing in attack/riding position?
- Is it taken wearing full gear? (I'm pretty sure most people don't)
- With most suspension forks, sitting on the seat is going to give you little to no fork sag, so do you sit down for one and stand up for the other? What about stiction and its effects on static sag?

That's for a well-established measurement that we have had for years, with a lot less variables than the 'bounce-sag' you describe - but it's still incredibly vague!

I haven't read the whole thread but from what I've skimmed, I doubt your method is going to net a number that is comparable between different riders (of different weights and strengths) - might work for the same rider between different bikes if you're lucky.

If manufacturers provided actual damping coefficients for different clicker settings, then that might actually be useful to compare between brands/models (obviously with some calculation needed to factor out leverage ratios for rear suspension), but seriously - most manufacturers don't even publish fork spring rates readily, I can't see them measuring and publishing damping rate data in a hurry.

 

[staike]

Rear sag on a DH bike should be 20-25% standing up and 30-35% sitting down. Fork sag is always measured in riding position, even though I don't measure the front sag as precise as the rear sag. Front sag is harder to dial in at a parking lot. I just take it for a ride and adjusts after that. It's funny how my bounce sag at the rear is around 90%, even though I don't use that much travel on a trail without jumps/drops.

 

[DirtyMartini]

Cmon, don't bash on Trek. I've checked the setup guide and it's a good start. I wish everyone else would give that kind of info or even a litte bit more. Shocks can be inconsistent but I don't think there is too much dispersion.

I'm sorry you heard my post that way. I in no way intended to bash on Trek, imply they're set up guide is not good, or the shocks they provide on their bikes are inconsistent.

Even if their shocks where 100% consistent, and their set up guide 100% perfect, my theory would still apply. I'm just saying that measuring LSC in terms of "clicks" is not nearly as transferable as bounce sag.

My apologies for any offense.

 

[ChrisKring]

Actually I have undertaken timed testing, averaged out over a number of runs using small-sample statistical analysis methods, that shows with a very high degree of confidence that suspension setup CAN make a measurable difference to your times. In one situation, two clicks on the rebound adjuster made about 0.8 seconds difference in a minute (over 4 minutes, means you could potentially save 3.2 seconds with a better rebound setting!). If you're racing at the top level and you're not anal about every single facet of your riding, then yeah, you might actually be losing races because your setup you are, than how well your bike's set up..

Interesting. I had considered this method to setup suspension with some of our juniors. However, I canned the idea since I thought the run order (fitness) would be the most significant. What P values did you observe?

 

[staike]

Bike: Iron Horse 7point5 2007
Rider weight: 130 lbs
Fork: 07 Marzocchi 66 RC2x
Shock: Marzocchi Roco Air WC

Front sag: 25%
Rear sag: 34%

Front bounce sag: 90%
Rear bounce sag: 88%

Settings
Fork:
Stock springs
Rebound: 18-20 clicks in I think
LSC: 2 clicks in
Bottom out: 0 clicks
No air preload

Shock:
70 psi in main chamber
190 psi in piggyback (bottom out)
Around 25 clicks rebound
HSC: 0 clicks.

 

[ThePriceSeliger]

Not sure if this has been touched on, but the new Manitou Dorados come with an adjustment sheet by weight. It includes air pressure, TPC+, HSC, and rebound. It's a great starting point for people who are unfamiliar with the inner workings, and are looking to go ride.