MegNeg

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MegNeg
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Posted: Jun 15, 2022 at 0:12 Quote
Looking for some help here as I'm at a loss. I have a Transition Spire and wanted more mid-stroke support so I thought I'd give the Meg Neg a try.

After install of Meg Neg: 2 neg bands, 2 reducers, same sag. There is now a noticeable clunk on top-out. I disassembled and removed all bands and reducers - same clunk (actually seems worse).

I then added back the regular can (possibly it was always there?) and there was nothing. Nice, smooth top-out as expected.

I've let the air out several times, cycled at 50 psi increments, etc. No change to the clunk other than it gets more pronounced with pressure.

Any ideas what could be the issue?

Posted: Jun 15, 2022 at 7:30 Quote
@MWills. Had same issue with a super deluxe ultimate. Would top out very bad even with just 100psi in it, and cycling the shock at 25psi intervals. Have had megneg’ s on 2 other SD’s with no issue. The shock it was topping out on had been revalved with a “special” tune on a stumpy evo. Had shock re-valved to LL tune and is all good now. No issues. Think it was the rebound tune on that was causing the issue.

Posted: Jun 15, 2022 at 7:47 Quote
oldnw wrote:
@MWills. Had same issue with a super deluxe ultimate. Would top out very bad even with just 100psi in it, and cycling the shock at 25psi intervals. Have had megneg’ s on 2 other SD’s with no issue. The shock it was topping out on had been revalved with a “special” tune on a stumpy evo. Had shock re-valved to LL tune and is all good now. No issues. Think it was the rebound tune on that was causing the issue.


you guys for sure have the top out spring still in there? (big wave spring with red carrier that slides on the damper body).

I've forgotten those a few times and get a clunk...

Posted: Jun 15, 2022 at 8:45 Quote
Installed megneg on V3 SC Bronson.

Weight: 215-220 lbs with gear
one negative band
zero positive tokens
260psi (about 35% sag)
2-4 clicks rebound, depending on terrain and goals
Ride enduro trails mostly with 1.5-3k foot descents, one bikepark day per week all season. Almost no xc terrain.


Overall, really liking this. Initial stroke is noticeably more supple, midstroke pop is adding a lot of playfullness to the bike. I started with one band and zero tokens, but am considering removing the band to see what it feels like, upping the pressure to get sag closer to 30% and/or adding a token to have fewer bottom outs. 35% is on the upper limits of sag but at 6'1", I feel it places me in the sweet spot geometry wise where the bike feels most balanced.

I recomend this product for this bike; provides with a much improved performance boost and makes the suspension more customizeable. It feels like a coil in the initial stroke without the linear feel/planted feel of a coil through the midstroke.

Posted: Jun 15, 2022 at 10:19 Quote
dcamp2 wrote:
oldnw wrote:
@MWills. Had same issue with a super deluxe ultimate. Would top out very bad even with just 100psi in it, and cycling the shock at 25psi intervals. Have had megneg’ s on 2 other SD’s with no issue. The shock it was topping out on had been revalved with a “special” tune on a stumpy evo. Had shock re-valved to LL tune and is all good now. No issues. Think it was the rebound tune on that was causing the issue.


you guys for sure have the top out spring still in there? (big wave spring with red carrier that slides on the damper body).

I've forgotten those a few times and get a clunk...

yes, i thought the same thing on first install. but i've had it on/off several times and it is always thereSmile

Posted: Jun 15, 2022 at 10:27 Quote
oldnw wrote:
@MWills. Had same issue with a super deluxe ultimate. Would top out very bad even with just 100psi in it, and cycling the shock at 25psi intervals. Have had megneg’ s on 2 other SD’s with no issue. The shock it was topping out on had been revalved with a “special” tune on a stumpy evo. Had shock re-valved to LL tune and is all good now. No issues. Think it was the rebound tune on that was causing the issue.

odd. i wouldn't think the dampener would really have any impact at the very end of the travel (at full rebound). even if i crank up the rebound compression, it is still there. also, this should just be the stock tune that comes on all of the Transition Spires but i'll have to investigate more.

Posted: Jun 15, 2022 at 11:11 Quote
Yes, had that on it.

Posted: Jun 20, 2022 at 23:38 Quote
I had the same harsh topout with the megneg (0 bands and my SD is re-valved) and this is my solution:

I increased the preload of the counter measure spring by adding a quadring (e.g. from a pike/lyrik airshaft or from the aircan itself) between the counter measure spring and the airpiston. The volume of the quadring is similar to one band, so if you add the quadring, it is recommended to remove one band to get the similar negative volume as before. Positive side effect is also a lower breakaway force! ;-)

Posted: Jun 24, 2022 at 9:19 Quote
Newbie here, awesome thread. Just about to fit a MegNeg to my Haibike AllMtn 3.0 2020. Have read through all 39 pages (twice) now. I think I have my head around it. Just one quote below confuses me a little, but it appears RMR knows his stuff so fully accept I might have my thinking wrong...!

R-M-R wrote:
so if you don't want a fully open MegNeg, you definitely wouldn't want a coil.

The way I see it, yes a fully open Meg would have the closest characteristics to a coil, but I'm not sure it's fair to say that if you don't like a fully open Meg, you won't like a coil either.

I'm basing this on the fact that to run a fully open Meg you need a lot of positive pressure to give anything like a decent sag point. From reading the rider reports, a fully open Meg is stiff and hard to bottom out, despite the fact it might actually be providing a pretty linear stroke. So stiff in fact that many feel the need to add neg bands to allow a reduction in pressure.

So with that in mind, a fully open Meg would be like a very high poundage coil shock. But a coil shock with a low poundage spring may work very well with the same rider who found an open Meg too harsh/stiff/difficult to bottom out. Thats the point I'm trying to make.

This is the issue I think I will find with my Meg, despite the fact I bought one and I'm willing to try it. In a nutshell, to get a 'linear as possible' stroke on an airshock we need loads of neg pressure. To get that, we need loads of positive pressure too. Which makes it super stiff. A bit like a high poundage coil spring. And there, it seems, is the crux of the problem when trying to get a linear feel from an airshock.

Of course, plenty of caveats around the fact that some bikes/riders/terrain may well use up full travel with a fully open Meg!

Posted: Jun 24, 2022 at 9:38 Quote
Planemo wrote:
Newbie here, awesome thread. Just about to fit a MegNeg to my Haibike AllMtn 3.0 2020. Have read through all 39 pages (twice) now. I think I have my head around it. Just one quote below confuses me a little, but it appears RMR knows his stuff so fully accept I might have my thinking wrong...!

R-M-R wrote:
so if you don't want a fully open MegNeg, you definitely wouldn't want a coil.

The way I see it, yes a fully open Meg would have the closest characteristics to a coil, but I'm not sure it's fair to say that if you don't like a fully open Meg, you won't like a coil either.

I'm basing this on the fact that to run a fully open Meg you need a lot of positive pressure to give anything like a decent sag point. From reading the rider reports, a fully open Meg is stiff and hard to bottom out, despite the fact it might actually be providing a pretty linear stroke. So stiff in fact that many feel the need to add neg bands to allow a reduction in pressure.

So with that in mind, a fully open Meg would be like a very high poundage coil shock. But a coil shock with a low poundage spring may work very well with the same rider who found an open Meg too harsh/stiff/difficult to bottom out. Thats the point I'm trying to make.

This is the issue I think I will find with my Meg, despite the fact I bought one and I'm willing to try it. In a nutshell, to get a 'linear as possible' stroke on an airshock we need loads of neg pressure. To get that, we need loads of positive pressure too. Which makes it super stiff. A bit like a high poundage coil spring. And there, it seems, is the crux of the problem when trying to get a linear feel from an airshock.

Of course, plenty of caveats around the fact that some bikes/riders/terrain may well use up full travel with a fully open Meg!

Yeah I don't think the Megneg is the same as a coil.

Personally I couldn't get on with mine. I tried to tinker with it a lot but still. It was great on smoother trails with jumps and drops. You could really feel you had something to push against, there was way more support and bottoming resistance. However on rocky and rooty trails (which are my favourite) it used waaaay less travel, but that came at a cost. The rear was more harsh and I had a lot more feedback through my feet. Still felt different than just jacking up the air pressure with the stock can tho.
At the end I was using it full of negative spacers and I was close to the air pressure I ran with the stock can. At that point it felt kinda pointless to use it.
Then I changed the Deluxe to a Super Deluxe and now the rear end finally feels how I wanted to. Still goes through the travel a bit too easily with the stock can, but at least it feels sooo much more plush. Or maybe that's just life with 140mm of travel.

Posted: Jun 24, 2022 at 10:33 Quote
Planemo wrote:
Newbie here, awesome thread. Just about to fit a MegNeg to my Haibike AllMtn 3.0 2020. Have read through all 39 pages (twice) now. I think I have my head around it. Just one quote below confuses me a little, but it appears RMR knows his stuff so fully accept I might have my thinking wrong...!

R-M-R wrote:
so if you don't want a fully open MegNeg, you definitely wouldn't want a coil.

The way I see it, yes a fully open Meg would have the closest characteristics to a coil, but I'm not sure it's fair to say that if you don't like a fully open Meg, you won't like a coil either.

I'm basing this on the fact that to run a fully open Meg you need a lot of positive pressure to give anything like a decent sag point. From reading the rider reports, a fully open Meg is stiff and hard to bottom out, despite the fact it might actually be providing a pretty linear stroke. So stiff in fact that many feel the need to add neg bands to allow a reduction in pressure.

So with that in mind, a fully open Meg would be like a very high poundage coil shock. But a coil shock with a low poundage spring may work very well with the same rider who found an open Meg too harsh/stiff/difficult to bottom out. Thats the point I'm trying to make.

This is the issue I think I will find with my Meg, despite the fact I bought one and I'm willing to try it. In a nutshell, to get a 'linear as possible' stroke on an airshock we need loads of neg pressure. To get that, we need loads of positive pressure too. Which makes it super stiff. A bit like a high poundage coil spring. And there, it seems, is the crux of the problem when trying to get a linear feel from an airshock.

Of course, plenty of caveats around the fact that some bikes/riders/terrain may well use up full travel with a fully open Meg!

I feel like comparisons of a megneg to a coil are only valid up to the sag point on the meg neg. Yes, it is similar to a coil in the sense that there is a plush, very compliant, and planted/high traction feel to the megneg in the initial stroke, up to or around the sag point.

As you go deeper in the travel, my experience has been that the megneg is much more progressive/poppy than the super deluxe. Megneg tuning is a problem solving exercise because the more linear (open/fewer bands in the neg chamber) the first part of the stroke is, the more progressive the latter stages of the stroke get, and they can get very progressive very fast, to the point where the ride can get harsh. The ends work against each other, so like a lot of bike tuning, you have to play the brackets and make a compromise somewhere. I believe this is why RockShox recomends the megneg for bikes with linear suspension curves or riders who blow through travel fast.

I have a V3 bronson, which has a pretty linear suspension curve, which is what the Megneg is designed for. The Megneg has provided that nice compliant/ linear beginning stroke that makes the ride plush and provides loads of traction (coil-like). At the same time, the Bronson is a lot more lively deeper in the travel, which is great for airs, pumping, generating speed out of features, etc (classic air shock characteristics). The Megneg does not work for everyone, although most people seem to rave about it... I think the bike's suspension curve has as much to do with the tune you develop in terms of Megneg performance.

I have very little experience with tuning coils, so it would be interesting to know if my comparison is valid from someone who rides both coil and megneg. Hopefully this is helpful.

Posted: Jun 24, 2022 at 11:47 Quote
MT36 wrote:

I feel like comparisons of a megneg to a coil are only valid up to the sag point on the meg neg. Yes, it is similar to a coil in the sense that there is a plush, very compliant, and planted/high traction feel to the megneg in the initial stroke, up to or around the sag point.

I certainly felt that. But when riding, when do you really use the 0-30% travel range? Personally I felt that I wanted more plushness on bigger hits when I was blowing through that travel range.
I kinda feel like that soft initial stroke is basically only really useful for "forcing" the sag you want. While actually riding the bike (not just pushing down on the seat) it was very very rare that I would actually feel that softer initial stroke.

Posted: Jun 24, 2022 at 12:04 Quote
MT36 wrote:
As you go deeper in the travel, my experience has been that the megneg is much more progressive/poppy than the super deluxe.

I do get what you are saying but on the flip side the graphs don't lie. It does seem that a MegNeg can indeed get close to the linear stroke of a coil. But what I think is happening is that in order to do this, so much positive is needed that the whole shebang becomes as hard as a rock (albeit with a linear stroke if you are heavy enough/doing big enough drops to actually use it).

It's almost as if we are fighting a losing battle in a desperate attempt to get a linear stroke. I can't help but feel that the whole airshock would need a complete redesign, with everything sized to work in harmony. Maybe a much bigger positive chamber would be needed, or a longer one. Or vice versa with the negative. Or maybe both. But slapping on a whole load of negative to a shock thats not designed for it seems to come with consequences somewhere else.

I'll still try it. I have no idea what the curves on the stock AllMtn are like so it's just a suck it and see really. My only concern is that I don't use any positive tokens at the moment so I already suspect it will end up too harsh for me.

Posted: Jun 24, 2022 at 12:17 Quote
HollyBoni wrote:
MT36 wrote:

I feel like comparisons of a megneg to a coil are only valid up to the sag point on the meg neg. Yes, it is similar to a coil in the sense that there is a plush, very compliant, and planted/high traction feel to the megneg in the initial stroke, up to or around the sag point.

I certainly felt that. But when riding, when do you really use the 0-30% travel range? Personally I felt that I wanted more plushness on bigger hits when I was blowing through that travel range.
I kinda feel like that soft initial stroke is basically only really useful for "forcing" the sag you want. While actually riding the bike (not just pushing down on the seat) it was very very rare that I would actually feel that softer initial stroke.

Where I live, we have a lot of small and medium size rocks, and lots of flat corners with loose/"marbley" trail surfaces. I feel the megneg is good at replicating that coil feel 0-30% travel stroke on this sort of terrain, in terms of traction and plush feel, over rapid small/medium hits.

For big hits, I could see where it may not be as plush, because the megneg gets so progressive deeper in the travel. It sounds like you may want to try a higher psi/less sag and fewer bands, without knowing your tune settings.

Posted: Jun 24, 2022 at 12:27 Quote
Planemo wrote:
MT36 wrote:
As you go deeper in the travel, my experience has been that the megneg is much more progressive/poppy than the super deluxe.

I do get what you are saying but on the flip side the graphs don't lie. It does seem that a MegNeg can indeed get close to the linear stroke of a coil. But what I think is happening is that in order to do this, so much positive is needed that the whole shebang becomes as hard as a rock (albeit with a linear stroke if you are heavy enough/doing big enough drops to actually use it).

It's almost as if we are fighting a losing battle in a desperate attempt to get a linear stroke. I can't help but feel that the whole airshock would need a complete redesign, with everything sized to work in harmony. Maybe a much bigger positive chamber would be needed, or a longer one. Or vice versa with the negative. Or maybe both. But slapping on a whole load of negative to a shock thats not designed for it seems to come with consequences somewhere else.

I'll still try it. I have no idea what the curves on the stock AllMtn are like so it's just a suck it and see really. My only concern is that I don't use any positive tokens at the moment so I already suspect it will end up too harsh for me.

I hear you. I do get the sense that there can be a more involved tuning process involved with the Megneg, because now you are tuning the negative chamber in addition to all the other parameters (psi, positive tokens, rebound, etc). You have way more control over that suspension curve now, so it can get complicated. I know some people have had to essentially start over from scratch with their settings and keep a log, adjusting one parameter, one ride at a time.


 
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