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SAG, SAG, SAG...


Paulo Mesquita
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Hello folks,

I need a suggestion, help, advice, voodoo, anything....

I have read and religiously followed the advice that on the V11 Sag control I should have between 3cm to 3,5cm of SAG.

Well, I bought the V11 from a friend who, unequipped, weighs 86kg. I weigh 89kg, but fully equipped I go by 95/96kg.

Now I've measured the SAG on my V11 (see the photos) and with a tape measure I saw that my SAG was short: 2.5cm. This measurement was done after I checked the pressure on the bottom valves and kept them at 120PSI as they were. (lower than the Inmotion charts recommendations for my weight)

And I still haven't touched the upper pressure valve 

In the meantime I upped the tire pressure from 35 PSI to 38 PSI.

NOTE: THE INFO ON THE PEDAL SAYS THAT FOR A RIDER WEIGHING BETWEEN 90KG AND 100KG THE LOWER VALVE PRESSURE SHOULD BE BETWEEN 130PSI AND 150PSI. It doesn't mention the top valves pressure...

Now, with 120PSI at the bottom, 96kg of weight and a SAG of 2,5cm...should I lower or increase the PSI at the bottom valves (not recommended for my weigh), or should I lower or increase the PSI on top. And if so...how much more?

Since 120psi is already lower than recommended for my weight, I'm not too keen on lowering even more the pressure on the bottom, due to the fact that with a bigger bump I might go too low on the rail. Maybe the two photos can help...

ADEVICE IS VERY, VERY WELCOME, PLEASE...

thanks

SAG 1.jpeg

SAG 2.jpeg

Edited by Paulo Mesquita
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Good question!  I have some theories on the bottom valve and it would be good to have a more veteran v11 rider answer.  My theory is the top valve controls the bounce back when your shock compresses to take a hit.  This is what I would like clarity on myself, but I believe the more pressure you add on top the faster the shocks return to the resting position.  too high of pressure on top can get your wheel to feel like a spring pogo stick.

I'm a heavy guy, I ride 170 psi on the bottom, bottom holds your weight and fluctuates based on weight, top from how I understand fluctuates but not as much.

I run 70 psi on top. 

However based on @mrelwood post in another thread there is not much harm in bottoming out a v11, I may ride with much more sag than I do right now.  I currently ride with @ 20% sag I may try 50% and see where it goes.

 

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13 minutes ago, Rich Sam said:

Good question!  I have some theories on the bottom valve and it would be good to have a more veteran v11 rider answer.  My theory is the top valve controls the bounce back when your shock compresses to take a hit.  This is what I would like clarity on myself, but I believe the more pressure you add on top the faster the shocks return to the resting position.  too high of pressure on top can get your wheel to feel like a spring pogo stick.

I'm a heavy guy, I ride 170 psi on the bottom, bottom holds your weight and fluctuates based on weight, top from how I understand fluctuates but not as much.

I run 70 psi on top. 

However based on @mrelwood post in another thread there is not much harm in bottoming out a v11, I may ride with much more sag than I do right now.  I currently ride with @ 20% sag I may try 50% and see where it goes.

 

I don't get the %20 and %50 meaning. I thought it was all about the difference in cm on the rail, with and without our weight...

Edited by Paulo Mesquita
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More air in the top means slower rebound speeds. I am 200lbs geared up and i put 140lbs in the bottom chamber and 40lbs in the top chamber. If it feels to bouncy put more air in the top.

Many people recommend half the bottom chamber in the top, but i found that to be a touch to slow for small repetitive bumps like crossing a grassy field.  If i was tuning the suspension for something more extreme like hitting stairs or mountian biking trails, i would want more pressure in the top chamber so i dont pogo off the wheel. 

The way i tuned my suspension was by bringing the wheel to grassy field that was fairly bumpy since thats what i wanted it tuned to do, rip over uneven terrain. I tried several pressures in the top and bottom chambers and settled on what i liked best which was 100 psi bottom and 40 top. However taking that setting to some more extreme offroading situations i ended up raising my bottom pressure to 140 which was still nice for the grassy field but managed rocks and roots better . 

Here is a video of my suspension working on road conditions with a tire pressure of ~34psi and travel speed of about 15 mph  

 

Edited by GoGeorgeGo
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TY @GoGeorgeGo , more the slower rebound, roger that.  I will add more pressure then I thought I was reducing pogo by adding less!  Pogo =  bad because that is what will buck you off when you hit a big bump.  Slower rebound will eat the bumps, but too slow and consectutive bumps may bottom you out.

 

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3 hours ago, Paulo Mesquita said:

I don't get the %20 and %50 meaning. I thought it was all about the difference in cm on the rail, with and without our weight...

20 percent sag means that when you stand on the pedals without bouncing it will compress @ 20% with just your body weight.  It's not an exact science you really don't need to measure, I would just eye ball it with a cell phone, thats what I do.

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The top chamber only affects the rebound speed indirectly, or as a secondary effect.

 The V11 shock is a very simple device. It’s simply a sealed tube with a sealed piston connected to the saddle. Compress it and the piston moves downwards, which the bottom chamber pressure resists. After compressing the piston goes back to the neutral position, determined by both the top and bottom pressures, and of course the rider’s weight.

Then there is the friction of the sliding mechanism that affects the sensitivity and rebound, and it changes depending on the manufacturing tolerances, as well as the amount of wear on the sliding rail and the plastic sliding bits/guides.

 Inmotion recommends 50psi at the top chamber for all riders. @Paulo Mesquita, you definitely need to check the top chamber pressures as the very next step! They may have leaked down to zero for all we know, since your sag is so short. They may also be uneven left and right, preventing the system from even sliding properly. That’s why only checking the bottom pressure doesn’t get you very far.

 When testing various pressures, I quite liked 0psi at the top, since it had the fastest rebound, making me float over sharp roots the smoothest. The bottom chambers had to be reduced by a LOT for the sag to remain suitable. (This is why I suspect that Paulo’s top chambers are missing air.) I eventually ditched the 0psi, since I didn’t have enough control over the up/down movement. We need to have a lot of control at how much we weigh down on the wheel at any given moment, more than I originally thought.

 

Some examples of the suspension behavior at my 105-110kg riding weight:

120/0 (bottom/top): The most floaty ride over tall roots, fastest rebound. Least amount of control for gnarly off-road. Tops out the easiest when riding down curbs, making a bang.

150/30: Still quite floaty, but more sensitive at small bumps. Better control off-road.

155/50: My go-to neutral. The best balance.

160/80: Tight but still reasonably sensitive at small bumps. Best for larger bumps, or fast riding off-road. Least comfortable at calm cruising.

 

 As you can see, the bottom pressure can be 120-160psi for the optimal sag (for my weight). It all depends on the pressure balance between top and bottom chambers.

 

 

 

Edited by mrelwood
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On 3/13/2021 at 1:22 AM, GoGeorgeGo said:

More air in the top means slower rebound speeds. I am 200lbs geared up and i put 140lbs in the bottom chamber and 40lbs in the top chamber. If it feels to bouncy put more air in the top.

Many people recommend half the bottom chamber in the top, but i found that to be a touch to slow for small repetitive bumps like crossing a grassy field.  If i was tuning the suspension for something more extreme like hitting stairs or mountian biking trails, i would want more pressure in the top chamber so i dont pogo off the wheel. 

The way i tuned my suspension was by bringing the wheel to grassy field that was fairly bumpy since thats what i wanted it tuned to do, rip over uneven terrain. I tried several pressures in the top and bottom chambers and settled on what i liked best which was 100 psi bottom and 40 top. However taking that setting to some more extreme offroading situations i ended up raising my bottom pressure to 140 which was still nice for the grassy field but managed rocks and roots better . 

Here is a video of my suspension working on road conditions with a tire pressure of ~34psi and travel speed of about 15 mph  

 

 

On 3/13/2021 at 7:34 AM, mrelwood said:

The top chamber only affects the rebound speed indirectly, or as a secondary effect.

 The V11 shock is a very simple device. It’s simply a sealed tube with a sealed piston connected to the saddle. Compress it and the piston moves downwards, which the bottom chamber pressure resists. After compressing the piston goes back to the neutral position, determined by both the top and bottom pressures, and of course the rider’s weight.

Then there is the friction of the sliding mechanism that affects the sensitivity and rebound, and it changes depending on the manufacturing tolerances, as well as the amount of wear on the sliding rail and the plastic sliding bits/guides.

 Inmotion recommends 50psi at the top chamber for all riders. @Paulo Mesquita, you definitely need to check the top chamber pressures as the very next step! They may have leaked down to zero for all we know, since your sag is so short. They may also be uneven left and right, preventing the system from even sliding properly. That’s why only checking the bottom pressure doesn’t get you very far.

 When testing various pressures, I quite liked 0psi at the top, since it had the fastest rebound, making me float over sharp roots the smoothest. The bottom chambers had to be reduced by a LOT for the sag to remain suitable. (This is why I suspect that Paulo’s top chambers are missing air.) I eventually ditched the 0psi, since I didn’t have enough control over the up/down movement. We need to have a lot of control at how much we weigh down on the wheel at any given moment, more than I originally thought.

 

Some examples of the suspension behavior at my 105-110kg riding weight:

120/0 (bottom/top): The most floaty ride over tall roots, fastest rebound. Least amount of control for gnarly off-road. Tops out the easiest when riding down curbs, making a bang.

150/30: Still quite floaty, but more sensitive at small bumps. Better control off-road.

155/50: My go-to neutral. The best balance.

160/80: Tight but still reasonably sensitive at small bumps. Best for larger bumps, or fast riding off-road. Least comfortable at calm cruising.

 

 As you can see, the bottom pressure can be 120-160psi for the optimal sag (for my weight). It all depends on the pressure balance between top and bottom chambers.

 

 

 

@GoGeorgeGo and @mrelwood, after intensive analysis of your precious inputs and experience, (btw, I'm an avid watcher of both your video blogs and publishings), I  followed @mrelwood's advice and checked the top pressure. It was still at 40psi (the owner before me was 85kg without gear, I'm 89kg without gear) so I did my math and decided to do 145psi bottom and 45 psi top. I did, however, have to do the pressure several times since I always lost about 10psi on each top valve when I went to recheck. So I loaded 10psi more on each at my 4th attempt guessing, with the previous 3 results, that I would end up with 145/45psi.

Now all I need to do is test it on the road and when I'm fully geared, Ill measure the SAG again. Tomorrow, probably I'll have the results.

I also lubed the suspension rails with WD-40 Dry PTFE.

BTW, @mrelwood, the 4 top screw holders of the side pads are all broken due to a fall the previous owner had, with only 200km on this wheel and that ripped his knee ligaments (thus the V11 being bought by me). So when I was following your video...I had no need to unscrew those four...

 

 

Edited by Paulo Mesquita
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19 hours ago, Paulo Mesquita said:

I don't get the %20 and %50 meaning. I thought it was all about the difference in cm on the rail, with and without our weight...

I don't have a V11, but it should be like a setup for MTB. 20% is the amount of sag of the full compression. Looking at your picture, you're more than 50% sag. Don't worry about the rebound settings till you get the sag dialed in or at least close to where you feel good about it. https://imgur.com/kyrsFcE

 

*I hope that picture showed up on the post :D

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53 minutes ago, slowpoke94133 said:

Oh, and don't use WD 40 anything unless it's made for suspension parts. It will destroy your seals. Go to a bike shop and get suspension lube.

Suspension lube works very well in lubricating the sliders, but the original main issue remains: being so close to the road it attracts dust and sand, marking more harm than good in the end. That’s why we are talking about waxes and dry lubes.

55 minutes ago, slowpoke94133 said:

I don't have a V11

...

Don't worry about the rebound settings

The V11 suspension is not like an MTB suspension. There isn’t a dedicated rebound adjustment, it’s the combination of top and bottom chambers pressure that determine both the sag and the rebound behavior. You might want to read a few posts up.

 

Quote

I did, however, have to do the pressure several times since I always lost about 10psi on each top valve when I went to recheck.

Actually, you didn’t lose any air from the shock. When you reattach the pump, the air from the shock pressurizes the house of the pump as well, lowering the pressure. What’s you see in the pump meter when you detach the pump, that’s what remains in the shock chamber. So you now have 155/55psi. Nothing wrong with that, but just so you know.

I suggest you watch the video I added, it is explained there as well.

Quote

What do you think is the best solution?

WhatsApp Image 2021-03-13 at 17.07.01.jpeg

The attachment points have been modified to thicker ones since batch 3b, and shouldn’t break anywhere near as easily as they used to. As a temporary solution Inmotion introduced metal clamps that screw into the saddle, and form a loop around the original plastic bracket. Maybe making something similar by yourself would be a good solution?

 Here’s how they look on their own:

20201028_110031_HDR-removebg-preview_108

https://www.euco.us/collections/v11-parts-online-listing/products/v11-saddle-reinforcement-kit

 

And installed:

image.thumb.png.f6b172d74b72149f1e309d67131ff23d.png

Edited by mrelwood
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2 minutes ago, mrelwood said:

Suspension lube works very well in lubricating the sliders, but the original main issue remains: being so close to the road it attracts dust and sand, marking more harm than good in the end. That’s why we are talking about waxes and dry lubes.

The V11 suspension is not like an MTB suspension. There isn’t a dedicated rebound adjustment, it’s the combination of top and bottom chambers pressure that determine both the sag and the rebound behavior. You might want to read a few posts up.

 

Actually, you didn’t lose any air from the shock. When you reattach the pump, the air from the shock pressurizes the house of the pump as well, lowering the pressure. What’s you see in the pump meter when you detach the pump, that’s what remains in the shock chamber. So you now have 155/55psi. Nothing wrong with that, but just so you know.

I suggest you watch the video I added, it is explained there as well.

The attachment points have been modified to thicker ones since batch 3b, and shouldn’t break anywhere near as easily as they used to. As a temporary solution Inmotion introduced metal clamps that screw into the saddle, and form a loop around the original plastic bracket. Maybe making something similar by yourself would be a good solution? I’ll try to find the photo.

 

I believe these are the saddle repair pieces mrelwood refers to. I would contact euco or ewheels and see if they can send you some im sure they will at most charge 10$ if not cover it for free. 

My installation wasnt perfect lol but they have held magnificently for me no issues at all

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5 hours ago, slowpoke94133 said:

I don't have a V11, but it should be like a setup for MTB. 20% is the amount of sag of the full compression. Looking at your picture, you're more than 50% sag. Don't worry about the rebound settings till you get the sag dialed in or at least close to where you feel good about it. https://imgur.com/kyrsFcE

 

*I hope that picture showed up on the post :D

I saw the picture, thanks. is the red marker you made where I should have the suspension without my weight on the wheel?

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@mrelwood, @GoGeorgeGo @slowpoke94133, I did a small video today, with me full gear weight, bouncing on the suspension. it was done with the old pressure of 40/120psi

Tomorrow, after the ride I'll do another video with the new pressure 55/155psi

 

Edited by Paulo Mesquita
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I can’t estimate the sag or the pressure balance from that video alone. If you’d jump up and down harder we might see the suspension either bottom out or top out, but I don’t think it’s needed if the measured sag is fine.

Btw, if the pressures were originally 120/40 after you inserted the pump, the actual chamber pressures were actually something like 130/50.

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5 hours ago, mrelwood said:

I can’t estimate the sag or the pressure balance from that video alone. If you’d jump up and down harder we might see the suspension either bottom out or top out, but I don’t think it’s needed if the measured sag is fine.

Btw, if the pressures were originally 120/40 after you inserted the pump, the actual chamber pressures were actually something like 130/50.

I'll check today after the alteration I did on the pressure. 

I'll try to jump and film it. If I fall... It's your fault 😂😂😂😂

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23 minutes ago, Paulo Mesquita said:

I'll try to jump and film it. If I fall... It's your fault 😂😂😂😂

That’s actually the reason why I said:

6 hours ago, mrelwood said:

but I don’t think it’s needed if the measured sag is fine.

😆🙈

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18 hours ago, Paulo Mesquita said:

I saw the picture, thanks. is the red marker you made where I should have the suspension without my weight on the wheel?

The yellow is top dead with no weight. The red should be about the 20% sag mark when you're standing on it with your riding gear. You're more than 50% sag.

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@mrelwood and @slowpoke94133 I was so tired after the ride today, I totally forgot to jump on the wheel and film it. I have a good excuse: before the 23km ride of today, the wife made me do a  5km hike ...I was totally bushed.

But the good news: according to your help and suggestions my ride today, under very dire wind conditions, actually felt very good suspension wise. I hope that when I measure the SAG it corresponds to the good results and feeling of today.

Tomorrow I'll measure for sure

cheers

 

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On 3/14/2021 at 11:32 AM, mrelwood said:

That’s actually the reason why I said:

😆🙈

@mrelwood @slowpoke94133 I measured the SAG and with the new psi pressures, the distance from unmounted to mounted is exactly the same: 2.5cm. I think it's because I increased the pressure on to and bottom exactly the same amount.

I did another video... jumping as hard as my 96kg and 61 years of age allowed ... and I think that the suspension does bottom out. 

 

 

Edited by Paulo Mesquita
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18 hours ago, Paulo Mesquita said:

and I think that the suspension does bottom out. Bujt you're the specialist...just check out the video and let me know, please...

Can’t see if the suspension bottoms out or not, the video is a bit “jumpy” 😜... But I can still see that it definitely does top out. This kind of setting has a danger of launching you up from the pedals in a bump, just as the 2.5cm sag (too little) would suggest.

 You could try 130/50psi next, and just measure if that’ll get the sag in the recommended ballpark (3-3.5cm). Bottoming out has no negative consequences, so you’d be much better off bottoming out than topping out the suspension.

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1 hour ago, mrelwood said:

Can’t see if the suspension bottoms out or not, the video is a bit “jumpy” 😜... But I can still see that it definitely does top out. This kind of setting has a danger of launching you up from the pedals in a bump, just as the 2.5cm sag (too little) would suggest.

 You could try 130/50psi next, and just measure if that’ll get the sag in the recommended ballpark (3-3.5cm). Bottoming out has no negative consequences, so you’d be much better off bottoming out than topping out the suspension.

@mrelwood, your wish is my command. 😁

I'll do that 130/50psi and see how it goes.

Thanks for the great guidance. 

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