Enduro/AM - The Weight Game

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Enduro/AM - The Weight Game
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flag B650wagon
Posted: Jul 10, 2019 at 9:17 Quote
Yes, for avg. riders should be fine, maybe lighter too. Heavier riders need custom tune. In general, heavier riders don't benefit from these air cans because we already require more psi than avg. weight riders. I would still benefit from a custom tune but the tuners say that they would not recommend the Evol air can in my case.
flag PHeller
O+
Posted: Jul 10, 2019 at 10:12 Quote
The EVOL and Debonair cans create more POSITIVE volume. Not good for heavier riders.

The MegNeg does the opposite.

Outside of the air volume adjustments however, do the tunes need to be revised for the increased negative volume (increase initial stroke sensitivity)? For example, I have a custom tune on a standard can and get a MegNeg - does my tune need updated?
flag badbadleroybrown
Posted: Jul 10, 2019 at 10:15 Quote
PHeller wrote:
The EVOL and Debonair cans create more POSITIVE volume. Not good for heavier riders.

The MegNeg does the opposite.

Outside of the air volume adjustments however, do the tunes need to be revised for the increased negative volume (increase initial stroke sensitivity)? For example, I have a custom tune on a standard can and get a MegNeg - does my tune need updated?
Spring rates and damper tunes are separate things... air can changes impact weight support characteristics, damper tuning only impacts velocity control.
flag R-M-R
Posted: Jul 10, 2019 at 10:24 Quote
PHeller wrote:
The EVOL and Debonair cans create more POSITIVE volume. Not good for heavier riders.

The MegNeg does the opposite.

Outside of the air volume adjustments however, do the tunes need to be revised for the increased negative volume (increase initial stroke sensitivity)? For example, I have a custom tune on a standard can and get a MegNeg - does my tune need updated?

Both EVOL and Debonair increased the negative volumes over their predecessors. Both are available with different positive volumes. These are separate parameters.

Increased positive volume is not necessarily a bad thing for heavy riders. A rider - light or heavy - is a candidate for a more progressive spring when the rider has a high ratio of strength to weight because sag is determined by weight, but bottom-out force is determined by how much of a hit the rider can endure. Trail characteristics are a secondary consideration: ex. trails filled with low speed, high duration impacts (ex. g-outs) will require more spring support.
flag PHeller
O+
Posted: Jul 10, 2019 at 10:25 Quote
badbadleroybrown wrote:
PHeller wrote:
The EVOL and Debonair cans create more POSITIVE volume. Not good for heavier riders.

The MegNeg does the opposite.

Outside of the air volume adjustments however, do the tunes need to be revised for the increased negative volume (increase initial stroke sensitivity)? For example, I have a custom tune on a standard can and get a MegNeg - does my tune need updated?
Spring rates and damper tunes are separate things... air can changes impact weight support characteristics, damper tuning only impacts velocity control.

https://www.pinkbike.com/news/the-tuesday-tune-ep-11-adjusting-spring-rate-vs-compression-damping.html

Minsta made this comment:
"+spring & +damping --> for faster riding (racing!)
+spring & -damping --> for more lively ride (park?)
-spring & +damping --> for more controlled ride (rough trail)
-spring & -damping --> for stable/slow riding (unknown/blind trail riding?)"

To which Vorsprung largely agreed.

It seems like if I was planning on softening the spring a little, running more compression damping (than with firmer spring or no additional negative volume) would be ok..
flag PHeller
O+
Posted: Jul 10, 2019 at 10:33 Quote
My gripe is this - because I'm a heavier rider I can never get an air shock to feel supportive in the mid-stroke without running too much pressure that initial stroke sensitivity is virtually nill.

I would sooner run less pressure for slightly more sag and bottom out the shock occasionally, but this sucks anytime you want to put the power down - its gets all wallowy. Adding compression damping would help with this a little.
flag mtbman1980
O+
Posted: Jul 10, 2019 at 10:49 Quote
PHeller wrote:
My gripe is this - because I'm a heavier rider I can never get an air shock to feel supportive in the mid-stroke without running too much pressure that initial stroke sensitivity is virtually nill.

I would sooner run less pressure for slightly more sag and bottom out the shock occasionally, but this sucks anytime you want to put the power down - its gets all wallowy. Adding compression damping would help with this a little.

Get a float X2 I have been more than happy with it as a big guy. It has great consistency on long dh runs. Supportive and supple.
flag R-M-R
Posted: Jul 10, 2019 at 10:49 Quote
PHeller wrote:
My gripe is this - because I'm a heavier rider I can never get an air shock to feel supportive in the mid-stroke without running too much pressure that initial stroke sensitivity is virtually nill.

I would sooner run less pressure for slightly more sag and bottom out the shock occasionally, but this sucks anytime you want to put the power down - its gets all wallowy. Adding compression damping would help with this a little.

This is the classic presentation of not enough negative spring and too much progressivity.

With a longer negative spring, you can run more pressure and still have initial sensitivity. More pressure will prop up the suspension after you come off the negative spring.

Less progressivity will allow you to access the end of the stroke, despite the high pressure.

Solution:

1. Run your Smash in Plush mode. It looks like you're already doing this.
2. Get a Meg Neg (RockShox) or Vorsprung Corset (Fox).
3. Remove all volume spacers and maybe get a high volume positive can.
- 3.1 ... or just get a coil shock
4. Use a little more low-speed compression damping.
flag PHeller
O+
Posted: Jul 10, 2019 at 11:12 Quote
I knew it! haha

Coil shock is already in the plans, but I got a Deluxe (Medium Compression, Low Rebound) so darn cheap that it makes sense to try a MegNeg, maybe even a custom tune, maybe even try a custom tune myself. I could go hogwild on this shock and still not spend new shock prices.
flag B650wagon
Posted: Jul 10, 2019 at 11:42 Quote
Guess I'm still missing something, I thought Evol and Magneg both increase negative air volume. Aren't they essential doing the same thing? Does Magneg increase negative without affecting positive?
flag R-M-R
Posted: Jul 10, 2019 at 11:51 Quote
PHeller wrote:
So here's one for ya: will the tune of the shock need to updated for the MegNeg? I'm sure most average weight riders will be fine, but if you're heavier or lighter and getting a custom tune, will the tune shop need to account for the increased negative volume?

In a perfect world, yes, but this assumes shock tunes are a lot more precise than they actually are. The same tune will span a wide range of average leverage rates, progressivity levels, rider weights, and rider strengths. For a tune to be sufficiently precise to account for the effect of the Meg Neg, we have to assume the non-Meg-Neg tune was essentially perfect. If so, you might make the compression damping a tiny bit less digressive to add a tiny bit more damping support at lower shaft speeds.

Most riders can barely tell the difference between 20 psi and 25 psi in their tires, so I think this is more theoretical than practical.

B650wagon wrote:
Yes, for avg. riders should be fine, maybe lighter too. Heavier riders need custom tune. In general, heavier riders don't benefit from these air cans because we already require more psi than avg. weight riders. I would still benefit from a custom tune but the tuners say that they would not recommend the Evol air can in my case.

First, no one benefits much from an EVOL can because Fox was too conservative with the changes over the previous can. Get a Vorsprung Corset.

The reason you're being told you wouldn't benefit from a more linear spring is probably because you're already bottoming out too easily, which is because the stock damping tune is based on a lighter rider.

B650wagon wrote:
Guess I'm still missing something, I thought Evol and Magneg both increase negative air volume. Aren't they essential doing the same thing? Does Magneg increase negative without affecting positive?

You're correct, but they're not equal:

- Meg Neg is a huge increase in the negative spring.
- EVOL is such a small increase that it barely counts; as mentioned above, the Corset is what the EVOL should've been.
flag R-M-R
Posted: Jul 10, 2019 at 11:58 Quote
PHeller wrote:
I knew it! haha

Coil shock is already in the plans, but I got a Deluxe (Medium Compression, Low Rebound) so darn cheap that it makes sense to try a MegNeg, maybe even a custom tune, maybe even try a custom tune myself. I could go hogwild on this shock and still not spend new shock prices.

If you don't mind the labour, then yeah, that's a great way to learn about damping and create something that's right for you.

With the recent availability of high-volume negative and positive chambers, an air shock can work for pretty much any rider on pretty much any bike.
flag riish
Posted: Jul 10, 2019 at 13:08 Quote
If you’re prepared to dive into it all and learn, reshimming and tuning a shock is a super worthwhile investment of your time. Plus then you’re able to service it more often than you otherwise would, and keeping suspension well maintained probably does more for performance than eking out marginal tuning gains.
flag B650wagon
Posted: Jul 10, 2019 at 14:48 Quote
R-M-R wrote:
PHeller wrote:
So here's one for ya: will the tune of the shock need to updated for the MegNeg? I'm sure most average weight riders will be fine, but if you're heavier or lighter and getting a custom tune, will the tune shop need to account for the increased negative volume?

In a perfect world, yes, but this assumes shock tunes are a lot more precise than they actually are. The same tune will span a wide range of average leverage rates, progressivity levels, rider weights, and rider strengths. For a tune to be sufficiently precise to account for the effect of the Meg Neg, we have to assume the non-Meg-Neg tune was essentially perfect. If so, you might make the compression damping a tiny bit less digressive to add a tiny bit more damping support at lower shaft speeds.

Most riders can barely tell the difference between 20 psi and 25 psi in their tires, so I think this is more theoretical than practical.

B650wagon wrote:
Yes, for avg. riders should be fine, maybe lighter too. Heavier riders need custom tune. In general, heavier riders don't benefit from these air cans because we already require more psi than avg. weight riders. I would still benefit from a custom tune but the tuners say that they would not recommend the Evol air can in my case.

First, no one benefits much from an EVOL can because Fox was too conservative with the changes over the previous can. Get a Vorsprung Corset.

The reason you're being told you wouldn't benefit from a more linear spring is probably because you're already bottoming out too easily, which is because the stock damping tune is based on a lighter rider.

B650wagon wrote:
Guess I'm still missing something, I thought Evol and Magneg both increase negative air volume. Aren't they essential doing the same thing? Does Magneg increase negative without affecting positive?

You're correct, but they're not equal:

- Meg Neg is a huge increase in the negative spring.
- EVOL is such a small increase that it barely counts; as mentioned above, the Corset is what the EVOL should've been.

From what I remember, the reason Steve at Vorsprung told me he didn't recommend Evol or Corset was that due to my heavier rider weight, having to run higher psi in my shock that I have plenty of negative spring. While running the Evol air can on my shock, I was maxing out the air pressure (needed to add more with Evol) to get 30% sag. Then my damping was cranked to try to settle it down. I couldn't find a happy medium between high/low speed....
flag R-M-R
Posted: Jul 10, 2019 at 15:10 Quote
B650wagon wrote:
From what I remember, the reason Steve at Vorsprung told me he didn't recommend Evol or Corset was that due to my heavier rider weight, having to run higher psi in my shock that I have plenty of negative spring. While running the Evol air can on my shock, I was maxing out the air pressure (needed to add more with Evol) to get 30% sag. Then my damping was cranked to try to settle it down. I couldn't find a happy medium between high/low speed....

There's a lot to unpack here.

First, the spring curve of a shock with minimal negative spring isn't good - it's just not. I it can act as a workaround to produce less sag at the maximum air spring pressure when everything is out of whack, but this isn't ideal, even as workarounds go.

The pressure rating of your shock isn't as rigid a number as you may think. The real pressure limit occurs when the shock is bottomed out, so the "maximum" static pressure probably allows you to run maximum volume reducers and still stay within the designed margin of safety at full compression. If you're not running maximum volume spacers, then you should be fine raising the static pressure well above the "maximum". The manufacturer could've provided a chart for this, but it's more complicated than what most companies want to provide to consumers, especially in the land of lawsuits.

There's nothing wrong with a little more than 30% sag, especially if your bike has a progressive motion ratio curve.

If your shock's damping tune isn't already firmer than stock, you should do that.

Ideally, you should find a bike with a lower average leverage rate to allow greater pressure.

 


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