MegNeg

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MegNeg
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Posted: Sep 2, 2021 at 12:59 Quote
slipperyb wrote:
Anybody know if RS makes a service kit for the Megneg, and what the part number might be? I did a basic air can service a few weeks back and notices the last big/fat O-ring that goes on the outside was a little stretched and isn't giving me the tightest seal all the way around. A googling comes up empty.

yeah, mine is like that also but if you go around it with you're finger you can make it even, it just stops the can from sliding down

Posted: Sep 2, 2021 at 18:50 Quote
coleboyb wrote:
yeah, mine is like that also but if you go around it with you're finger you can make it even, it just stops the can from sliding down

Yeah, I did just that. I’m just thinking it will be even worse the next time I go to service and I’d like to replace the various o-rings and seals, in and out, next time. So looking for a megneg service kit. Maybe RS doesn’t have one yet?

Posted: Sep 3, 2021 at 3:11 Quote
dadbod72 wrote:
I have been reading this thread for the last two hours and there is some great information and recommendations on here. However, I could not find any information about running a MegNeg on a Yeti SB150. Does anyone have any experience running the MegNeg on the this bike?

I've been running the MegNeg on my Super Deluxe Ultimate for about 6 weeks. I just went with the Rock Shox recommendation of removing 1 positive token and adding two negative bands. This for the most part has been ok, but I am looking for the Goldilocks set-up.

I am considering the following alternative set-ups

0 positive & 0 negative
0 Positive & 1 negative
0 Positive & 2 negative

I have not changed anything but the sag since initial set-up. I started running at about 35% sag, but was bottoming out too often. I am now at 30% and have not achieved full travel. The bike is fairly linear, so I'm thinking the MegNeg should work well with 30% sag. For reference, my rider weight is approximately 215 lbs.

Any thoughts or recommendations would be greatly appreciated...thanks!

Are you running any positive tokens now?
If I were you I would start with 0 positive and 0 negative and the manufacturer's recommendation for sag.

Posted: Sep 3, 2021 at 4:18 Quote
slipperyb wrote:
coleboyb wrote:
yeah, mine is like that also but if you go around it with you're finger you can make it even, it just stops the can from sliding down

Yeah, I did just that. I’m just thinking it will be even worse the next time I go to service and I’d like to replace the various o-rings and seals, in and out, next time. So looking for a megneg service kit. Maybe RS doesn’t have one yet?

Mine came with a spare set.........

Posted: Nov 1, 2021 at 17:20 Quote
CSdirt wrote:
dadbod72 wrote:

I am considering the following alternative set-ups

0 positive & 0 negative
0 Positive & 1 negative
0 Positive & 2 negative

I have not changed anything but the sag since initial set-up. I started running at about 35% sag, but was bottoming out too often. I am now at 30% and have not achieved full travel. The bike is fairly linear, so I'm thinking the MegNeg should work well with 30% sag. For reference, my rider weight is approximately 215 lbs.

Any thoughts or recommendations would be greatly appreciated...thanks!

need more info on what you want to achieve, but I'm feeling helpful today so I'll take a stab at it...

-start with recommend sag for bike. Keep sag constant while you do initial set up. That will require more or less air depending on bands/tokens used.

-Assuming correct sag and not bottoming? then remove another positive token and change air to achieve same sag.

-Dont have any positive tokens to remove? then start filling up the negative air chamber and effectively you reduce the increased air volume of the megneg. Adding negative bands will make initial stroke relatively stiffer than less bands, but also reduce mid stroke support and ultimately bottom out (less total air for a given sag point).

-Now, if you add enough negative bands and start bottoming too much...now what?!! Depends on how you want the bike to feel. You could remove a band = increase airspring midstroke/bottom suport and create softer initial stroke (stronger negative spring) OR add a token if you like the midstroke and starting stroke but just don't want to bottom as much.

Anyway, I could be explaining this wrong, but that's how I worked through setup on my bike. Hope it helps!!

Thanks for the advice. I could't get it to feel the way I wanted, so I ended up getting a 2022 Fox X2, which feels so much better.

Posted: Nov 11, 2021 at 21:41 Quote
I have a '19 Meta AM 29 and running a Cascade link. Anyone tried this combo with the MegNeg?

Posted: Nov 15, 2021 at 10:31 Quote
Orings- 44x3 is the fatty that holds the sleeve on. There should have been a spare in your kit.


You can buy o-rings here:

https://www.theoringstore.com/store/index.php?main_page=index&cPath=368

Or Mcmaster Carr is good but you'll get a 50 pack or something.

No guarantee the o-rings will be oil-compatible but the fat one shouldn't be getting oily anyways.




The Meta would work nice with a MEGNEG.

Posted: Nov 15, 2021 at 11:27 Quote
dcamp2 wrote:
Orings- 44x3 is the fatty that holds the sleeve on. There should have been a spare in your kit.


You can buy o-rings here:

https://www.theoringstore.com/store/index.php?main_page=index&cPath=368

Or Mcmaster Carr is good but you'll get a 50 pack or something.

No guarantee the o-rings will be oil-compatible but the fat one shouldn't be getting oily anyways.




The Meta would work nice with a MEGNEG.

You can guarantee the o-ring will be oil-compatible. It's in the specs! Specifically, you want this one: https://www.theoringstore.com/store/index.php?main_page=product_info&cPath=368_65_66&products_id=41687. The Viton material is just fine with oils and has the bonus feature for this particular application of being highly resistant to UV (aka sun) exposure. So it will last much longer before cracking when sitting on the outside like this.

Signed, your friendly neighborhood mountain-biking chemist

Posted: Nov 15, 2021 at 13:10 Quote
We usually do a compatibility test with our exact oils and the exact rubber- you'd be surprised to see how much variability in shrink/swell you see between different manufacturers of what should be the same NBR 70 rubber o-rings.




Anyways agree the viton one should work well for the outside retention o-ring.

Posted: Nov 15, 2021 at 13:47 Quote
dcamp2 wrote:
We usually do a compatibility test with our exact oils and the exact rubber- you'd be surprised to see how much variability in shrink/swell you see between different manufacturers of what should be the same NBR 70 rubber o-rings.




Anyways agree the viton one should work well for the outside retention o-ring.

Oh, I get that. When spec-ing for industry the compatibility ratings are a loose guide. And you still need to have a great relationship with the supplier so that you at least get a heads up if they change something in their process that's going to change performance after you've gone through the trouble of selection!

Also in industry, at least when manufacturing something in volume that contains o-rings, cost matters in a way that it doesn't for a consumer doing a rebuild. NBR is cheaper than Viton for, but unless you are specifically looking for sub-zero performance, I've never found a reason to save the $2 using NBR when Viton is available. Way fewer of those edge cases of swell/shrink because its chemical resistance is overkill for suspension fluids in general.

Since you're here anyway, dcamp2, what actually prevents running the shortest MegNeg kit on a 45mm stroke shock?

Posted: Nov 15, 2021 at 17:47 Quote
melanthius wrote:

Since you're here anyway, dcamp2, what actually prevents running the shortest MegNeg kit on a 45mm stroke shock?



We only made aircans down to 55 length, so if you put a 55 length can on a 45 stroke shock you'll run the seal off the end of the damper body at full travel and all kinds of bad stuff will happen.

It was a product management decision to not do the 45 kit... we had no idea if these would sell at all or not and they were aimed at aggressive enduro bikes (mostly 55 and 65 stroke shocks).

Posted: Nov 15, 2021 at 19:47 Quote
That’s what I was afraid of, thanks for confirming.

Posted: Nov 24, 2021 at 7:23 Quote
Heeven wrote:
Examples of brands that utilize this type of leverage curve are Evil, Transition and Forbidden.

Definitely agree on this one. I ride an Evil Calling. They don't call it the downhillers trail bike for nothing! Just when I thought it couldn't get any better, MegNeg shows up.

I'm more of a jump/in-the-air rider. MegNeg made an incredible bike even more capable. I don't have any issues with lack of support off the top of jumps like some people have mentioned. I'm a heavier rider as well. But it made Pisgah trails like Bennett Gap, Avery Creek, and Black Mtn so much more fun.

It gets the double thumbs up from me.

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