MegNeg

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MegNeg
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Posted: Apr 28, 2021 at 9:22 Quote
Question for the smart folks. I've been reading this thread and trying to understand how the megneg works and have some questions specific to my bike

Bike: transition sentinel v2, 24% "linear" progression. RS SD select+, currently run it 250psi, 1 token, and 28%ish sag. I use almost full travel on rougher sections, and only bottom out when i do something wrong. setup is pretty close to ideal as is, but since i sometimes like to tinker, i have a megneg in the garage waiting to go on

My understanding of the megneg is start with 0 bands and 0 tokens. Up the PSI to get back to 28%ish sag (guessing around 300psi). Now i understand that the breakaway force for the first 1/3 of the stroke is supposed to be softer, and the increased PSI will make the mid/bottom stroke harder. But given most riding is done at or below sag, won't this just make the bike stiffer/rougher? Is the "softer off the top" worth the extra harshness in the mid/end stroke?

I tried a coil, but found the SD select+ 85% as good and kept it because i didn't feel the coil was worth the weight/price. Hoping the megneg can bridge 10% of the SD select+ vs the coil.

Appreciate any insight here!

Posted: Apr 28, 2021 at 9:32 Quote
whiteranger3 wrote:
But given most riding is done at or below sag, won't this just make the bike stiffer/rougher? Is the "softer off the top" worth the extra harshness in the mid/end stroke?

This was my experience on the Norco Sight (18% progression). The main impact of the MegNeg is the extra support that comes from being able to run a higher spring rate. On some bikes, for some riders, this support is beneficial. In other cases, the spring rate is too much.

I preferred the regular air can for my use. But I like a coil shock even more than both options. I get more support early in the stroke without an excessively high spring rate deeper in the stroke.

The MegNeg is worth trying, but you may not like it. It's not a slam dunk upgrade in all cases, in my opinion.

Posted: Apr 28, 2021 at 9:33 Quote
I came across this thread where spring curves of regular and MegNeg cans were measured (at the same spring pressure). Some might find this interesting: https://www.mtbr.com/threads/deluxe-standard-can-vs-megneg-graphs.1181616/

I'll let those interested read the details, but one theory that came out of this was that the MegNeg will force a certain amount of sag similar to how the old Monarch Debonair did. This could explain why I was getting about 35% sag (measured seated) regardless of what positive pressure I ran, within reason.

Posted: Apr 28, 2021 at 10:48 Quote
Commencal Supreme: I'm not sure if there's been a recent update since my models. They were created from the geometry schematic on Commencal's website in February and a good photo that produced almost identical results. From those, the linkage is less progressive than typical for a DH bike, making it suited to an air spring or a progressive coil. The shape of the curve is well suited to a MegNeg.


whiteranger3,

Your understanding is mostly correct. If you use the same sag as before, the "breakaway" force won't be much different.

There are two typical ways to implement a MegNeg, compared to a good set-up on a smaller negative spring:

1. Same sag, lower compression ratio (remove a token or two)
• Similar support for the first half-ish of the travel (including the portion from top-out to sag, so it feels like less than half of the travel)
• More support in the mid-stroke
• Similar support at the end

2. More sag, same compression ratio
• Less support (more "plush") in the first half-ish of the travel
• Similar support in the mid-stroke
• Similar to slightly more support at the end, if the pressure was raised a little to maintain a similar mid-stroke

What are you looking to get from the MegNeg, i.e. where do you want more support, where do you want the same, and where do you want less?

Posted: Apr 29, 2021 at 8:59 Quote
R-M-R wrote:
whiteranger3,

Your understanding is mostly correct. If you use the same sag as before, the "breakaway" force won't be much different.

There are two typical ways to implement a MegNeg, compared to a good set-up on a smaller negative spring:

1. Same sag, lower compression ratio (remove a token or two)
• Similar support for the first half-ish of the travel (including the portion from top-out to sag, so it feels like less than half of the travel)
• More support in the mid-stroke
• Similar support at the end

2. More sag, same compression ratio
• Less support (more "plush") in the first half-ish of the travel
• Similar support in the mid-stroke
• Similar to slightly more support at the end, if the pressure was raised a little to maintain a similar mid-stroke

What are you looking to get from the MegNeg, i.e. where do you want more support, where do you want the same, and where do you want less?

The second option sounds like what i'm after, softer over the small chattery stuff like the coil i tried was. I will experiment and see what i come up with and report back. Might be a couple weeks, for some reason i can't bring myself to pull apart my shock out of laziness!

Posted: Apr 30, 2021 at 23:01 Quote
R-M-R wrote:
Commencal Supreme: I'm not sure if there's been a recent update since my models. They were created from the geometry schematic on Commencal's website in February and a good photo that produced almost identical results. From those, the linkage is less progressive than typical for a DH bike, making it suited to an air spring or a progressive coil. The shape of the curve is well suited to a MegNeg.


whiteranger3,

Your understanding is mostly correct. If you use the same sag as before, the "breakaway" force won't be much different.

There are two typical ways to implement a MegNeg, compared to a good set-up on a smaller negative spring:

1. Same sag, lower compression ratio (remove a token or two)
• Similar support for the first half-ish of the travel (including the portion from top-out to sag, so it feels like less than half of the travel)
• More support in the mid-stroke
• Similar support at the end

2. More sag, same compression ratio
• Less support (more "plush") in the first half-ish of the travel
• Similar support in the mid-stroke
• Similar to slightly more support at the end, if the pressure was raised a little to maintain a similar mid-stroke

What are you looking to get from the MegNeg, i.e. where do you want more support, where do you want the same, and where do you want less?

Thanks for the info on the supreme. I believe they got more progressive for 2021 but can't find any info online to confirm this.

Posted: Apr 30, 2021 at 23:22 Quote
The World Cup team was testing more progressive links and I think I also recall something about that making it to production.

Posted: May 7, 2021 at 6:31 Quote
In my personal experience bikes that have progressive early stroke, then flatten out a lot at midstroke, before ramping up again in the last 25% of the stroke work best with the Meg Neg as it naturally compliments this type of leverage curve. Examples of brands that utilize this type of leverage curve are Evil, Transition and Forbidden. Of all the bikes I tried with the Meg Neg air can the 2017 alloy Transition Patrol and 2019 Carbon Transition Sentinel demonstrated the most noticeable on trail benefits from the larger negative spring. Both of those bikes display some of the most active, supportive and plush rear ends simultaneously with the Meg Neg that I've felt on any bike anywhere. I remember my first outting on the Patrol I immediately noticed the vastly more supple top end, hit a small drop with a steep landing to g out that I would often clap the shock on if I wasn't being very careful with weight distribution and pitch orientation on the landing. On this particular run I intentionally touched down front wheel first and then shifted the majority of my weight too far back on the g out and didn't clap. I thought okay watch next punchy techy climb that requires I get out of the saddle to clean I'll be bobbing like a bouy in the Berring Sea . . . Nope. Climb switch off, suspension active enough to move the rear wheel out the way of all trail detritus and detectable Bob was as non-existent as it gets on 160mm 27.5 bikes. I was stunned. That alloy Patrol was one of the most fun bikes I have ever had the privilege of owning. Not to mention the dude I bought it from got Transitions blessing to chemically strip the paint and not void the warranty. It was raaawww with a black rocker link and black rear triangle, looked sick as fuuuck

Posted: May 9, 2021 at 12:13 Quote
Hi, looking some advise with my megneg on my privateer 161. I am running 2 bands and 2 tokens but I almost bottom out on big hits and looking for more support in middle stroke. I have seen people removing all tokens in positive chamber but for me I am guessing I will bottom out even more without tokens right? I am going to do some testing later today and wondering where to start, any advise? Cheers

Posted: May 9, 2021 at 12:45 Quote
Looking for some advice. I have a 2021 commencal supreme with a super deluxe ultimate. I find it use full travel too often. Not sure if I would benefit more from the megneg (I've read it helps with bottom out resistance as the shock requires more psi) or just add a token. Thoughts?

Posted: May 9, 2021 at 13:16 Quote
lilaubert wrote:
I am guessing I will bottom out even more without tokens right?

Depends on the base pressure. If you were to run it fully open, that would require more pressure, which could offset the removal of the positive spring reducers. Your sag may change a little. Fully open is definitely the most direct path to getting more mid-stroke support. If that's too extreme for your taste, try one reducer on each side.

You can't get more mid-stroke support without removing support elsewhere - if you didn't, you would just have more support everywhere, which means not getting full travel. That's the central theme in choosing between different, viable, suspension set-ups: trading one type of support for another.


ThunderChunk wrote:
Looking for some advice. I have a 2021 commencal supreme with a super deluxe ultimate. I find it use full travel too often. Not sure if I would benefit more from the megneg (I've read it helps with bottom out resistance as the shock requires more psi) or just add a token. Thoughts?

If you're bottoming out too easily, you need more support. Any spring - MegNeg or otherwise - can offer more support. The MegNeg can also offer different support.

• If you're happy with how your suspension currently feels on medium impacts and want more support only at the end of the stroke, add positive spring reducers (tokens).
• If you want more support everywhere, add pressure.
• If you want more support in the middle and, optionally, at the end without more support in the early stroke, try a MegNeg.

You may also benefit from more high-speed compression damping, which can - and maybe should - be addressed separately and in parallel to the spring changes.

Posted: May 9, 2021 at 17:05 Quote
R-M-R wrote:
lilaubert wrote:
I am guessing I will bottom out even more without tokens right?

Depends on the base pressure. If you were to run it fully open, that would require more pressure, which could offset the removal of the positive spring reducers. Your sag may change a little. Fully open is definitely the most direct path to getting more mid-stroke support. If that's too extreme for your taste, try one reducer on each side.

You can't get more mid-stroke support without removing support elsewhere - if you didn't, you would just have more support everywhere, which means not getting full travel. That's the central theme in choosing between different, viable, suspension set-ups: trading one type of support for another.


ThunderChunk wrote:
Looking for some advice. I have a 2021 commencal supreme with a super deluxe ultimate. I find it use full travel too often. Not sure if I would benefit more from the megneg (I've read it helps with bottom out resistance as the shock requires more psi) or just add a token. Thoughts?

If you're bottoming out too easily, you need more support. Any spring - MegNeg or otherwise - can offer more support. The MegNeg can also offer different support.

• If you're happy with how your suspension currently feels on medium impacts and want more support only at the end of the stroke, add positive spring reducers (tokens).
• If you want more support everywhere, add pressure.
• If you want more support in the middle and, optionally, at the end without more support in the early stroke, try a MegNeg.

You may also benefit from more high-speed compression damping, which can - and maybe should - be addressed separately and in parallel to the spring changes.

Thanks for the info. I forgot to add I'm happy with how it feels currently. I just need some extra bottom out resistance. The supreme is extremely plush off the top of the stroke so not sure if the megneg would make it feel too supple.

Posted: May 9, 2021 at 17:38 Quote
[Quote="R-M-R"]
lilaubert wrote:
I am guessing I will bottom out even more without tokens right?

Depends on the base pressure. If you were to run it fully open, that would require more pressure, which could offset the removal of the positive spring reducers. Your sag may change a little. Fully open is definitely the most direct path to getting more mid-stroke support. If that's too extreme for your taste, try one reducer on each side.

You can't get more mid-stroke support without removing support elsewhere - if you didn't, you would just have more support everywhere, which means not getting full travel. That's the central theme in choosing between different, viable, suspension set-ups: trading one type of support for another.

Got it. Here is what I tried. With same sag 30% I removed 2 bands (so now no band in negative) and I removed 1 token in positive (only gnar token in positive). The result is a way better middle stroke support, love it but I still bottom out on hard landing after a jump.
I am guessing that I should bottom out in some cases right? Might try to add a token in positive to see the differences but it might be too much

Posted: May 9, 2021 at 18:48 Quote
ThunderChunk,

If you want it to be exactly the same, just with more support at the end, you'll get that by adding a reducer on the positive side. It would also be a viable option to switch to the MegNeg and maintain your current sag. This would create similar support in the first half-ish of the travel, a little more support in the middle, and significantly more at the end.


lilaubert,

Yes, you should use full travel sometimes - that's why it's there! If you feel you're bottoming out too harshly or too easily, though, you need more support. This could come from high-speed compression damping, base pressure, and/or ramp-up (compression ratio, i.e. tokens). Your choice on whether it's a problem and, if so, how to solve it.

Posted: May 9, 2021 at 20:08 Quote
Thanks R-M-R always good advises


 
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