[ChrisRobin]

A long time ago when I had my Marzocchi 888 Ti with Avalanche cartridge, I didn't really have that problem. Craig had given me the lecture of adding LSC in order to keep the fork higher in its travel so the HSC could do its job. Overall it worked great.

Fast forward to these days: I'm currently on a 2019 Boxxer WC. Overall the fork performs okay in steep technical stuff (the lack of stiction is pretty impressive), but stutter bumps and braking bumps seem to not get absorbed at all.

So is this simply because an air spring AND a generic damper like the Charger 2.0 isn't really designed to perform as well as my old coil sprung Avy'd 888, and I've done the best I can with what I have? Or am I missing something?

 

[djjohnr]

Have you tried more spring and less LSC?

 

[englertracing]

A long time ago when I had my Marzocchi 888 Ti with Avalanche cartridge, I didn't really have that problem. Craig had given me the lecture of adding LSC in order to keep the fork higher in its travel so the HSC could do its job. Overall it worked great.

Fast forward to these days: I'm currently on a 2019 Boxxer WC. Overall the fork performs okay in steep technical stuff (the lack of stiction is pretty impressive), but stutter bumps and braking bumps seem to not get absorbed at all.

So is this simply because an air spring AND a generic damper like the Charger 2.0 isn't really designed to perform as well as my old coil sprung Avy'd 888, and I've done the best I can with what I have? Or am I missing something?

Is the new bike longer and slacker?

 

[slyfink]

Have you tried more spring and less LSC?

This. I think it was Darren (Push) that said it on a podcast, and Steve from Vorsprung that explained it to me in an email: counter-intuitively, softening initial stroke by dropping air spring pressue leads to a harsher ride because the fork will ride deeper in its travel and hit the end-stroke air spring "wall" sooner and more often.

I guess with air sprung forks you need to rely on the spring rate more than valving for initial stroke compliance?

Darren also said he flips his bike upside down every chance he gets to allow the lower leg oil to drip down to the dust wiper seals and keep them lubed for better initial stroke compliance. I've been doing that for the past couple of years, and find it works remarkably well.

 

[Sandwich]

in my experience, this sort of feedback is likely due to either stiction or too much HSC....or at least, IME it's been remedied by reducing HSC or getting a fork that isn't dreadful.

When I switched from my #1 favorite 2010 boxxer to a Marz 380, the difference in stiction was phenomenal. The marzo had an inferior damper, but the chassis was worlds better, and this remedied the small bump feedback.

I eventually dumped that bike, got a Fox 40 RC2, and got a bit faster. I found that by dialing back HSC a click or two, I got less small bump feedback at high speed (ie braking bumps before a berm or gravel "scree" before a tree section). This is a coil 40, and I am/was on the correct spring for my weight. I followed @Udi 's advice for damper tuning.

Good luck...I can't imagine the new boxxer can't be tuned to be more capable than your Marz, then again those forks were some of the most supple out of the box and craig knows his stuff even if he communicates poorly...so it might take some effort.

 

[ChrisRobin]

I'll need some more testing because I've realized a couple things after a reading responses.

Yup, the bike is longer but not slacker compared to the bike that I had before.

Throughout the day yesterday, I tried more/less LSC and HSC but it didn't seem to make a huge difference. I think that's because the Charger 2 damper is known for having compression adjusters that don't do a lot.

I recently replaced the 190mm air spring with 200mm. I also took out the single air token because with it in there, I couldn't use full travel - always had about an inch and a half left. But I think the culprit is air pressure. I was running around 140 psi (142 psi at 190mm). That got me at my usual preferred sag height but I think I need to go stiffer. I think I just end up riding into that wall where the air spring ramps up. Based on reviews I've read, all these lighter guys were running either the same pressure or more. The frustrating part is SRAM's setup guides are non-existent unless you download that app and enter in your serial number.

Next time I go up, I'll try closer to 150psi, less HSC and keep the LSC in the middle and go from there.

 

[6thElement]

I've been playing the same game for a while now. My previous coil Boxxer I could never get it work well over stutter.

New bike has a 29 Boxxer Ultimate, the SRAM tuning page recommends 126psi at my weight. I think I'm at 95psi, 0hsc, 4lsc...I need to check the sag at that pressure, but at 126psi I was only using 6" of travel.

 

[Westy]

Too much rebound causing the fork to ride too deep into the travel?

 

[bullcrew]

Just did this shit with the 40 avy..as some recommended on here and Craig got after me and said the same thing, cause I like lower psi it will ride like shit in chatter...and it did..

I'm 15% sag as well I ride higher in travel due to some weight shift and mullet....I like to sit deeper but it's only a parking lot number on trail it had more than enough drop out to handle voids and still maintain smooth controlled lines....

85 recommend for my 40 and my weight....I went to just under 95 and added 2 air tokens ....my thinking was this is gonna lead me down the wrong rabbit hole..well I caught the damn rabbit...no more holes...now I have a damn good baseline to dial from....

Added psi not volume, actually reduced some volume with spacers and my low speed is all the way open for chatter so is my slow speed compression.....

 

[OGRipper]

IME, stutter- and braking-bumps are a HSC issue, not LSC - they're successive hits that require high-speed suspension travel in both compression and rebound. So, too much HSC and/or HSR will do that to you. The impact of too much HSC should be clear - fork won't compress fast enough to absorb hits. But too much HSR is also an issue, especially when combined with relatively low pressure - your fork won't rebound fast enough to be ready for the next hit.

 

[mykel]

Still running a 2013 Ti sprung 888 with Avy cartridge.
Braking bumps? Errr...what are those?
It will take a 27.5 with an Assegai, so I'm

 

[StiHacka]

Yup, the bike is longer but not slacker compared to the bike that I had before.

If the front end is longer, that will accentuate any stiction / flex issues, too, despite the same HA, no?

 

[Flo33]

IME, stutter- and braking-bumps are a HSC issue, not LSC - they're successive hits that require high-speed suspension travel in both compression and rebound. So, too much HSC and/or HSR will do that to you. The impact of too much HSC should be clear - fork won't compress fast enough to absorb hits. But too much HSR is also an issue, especially when combined with relatively low pressure - your fork won't rebound fast enough to be ready for the next hit.

Rebound speed and force are determined and direct proportional to used travel and resulting load on your spring. I don't think HSR damping will play a big role in brake bump stutter, especially with high amounts of HSC damping.

 

[djjohnr]

You

IME, stutter- and braking-bumps are a HSC issue, not LSC - they're successive hits that require high-speed suspension travel in both compression and rebound. So, too much HSC and/or HSR will do that to you. The impact of too much HSC should be clear - fork won't compress fast enough to absorb hits. But too much HSR is also an issue, especially when combined with relatively low pressure - your fork won't rebound fast enough to be ready for the next hit.

You still have to push past the low speed compression range to get to the high speed knee. Reduce too much HSC and you’ll reduce support on the really big compressions.

 

[ChrisRobin]

After reading everything I think my air pressure is a little low, causing the fork to feel decent in the slower chunky stuff but at speed over the stutter bumps, it's sitting too low.

I also messed with the LSR and at one point it did help a bit to back it off.

Also, on hard compressions (or maybe rebounding after hard compression), the fork sounds like the squeaky toy my dog chews on.

 

[kidwoo]

being on the ground

 

[Jm_]

New forx aren't as good as custom 15 years ago? I'm shocked I tell you!

 

[Bikael Molton]

Here's some real basic $.02 that you may have already thought of.

Underspringing air forks is just bad, and I think a lot of guys run their forks like that because so many air springs feel too stiff and/or stictiony off the top.

Struggling to get full travel on air forks seems a common complaint these days, especially with Rockshox products. You may want to measure how many MMs you are truly getting, in case you have more than 200mm of visible stanchion. I never got the final 1" of travel on my Lyrik, but didn't really care, because staying high in steeps and G-outs was more important to me.

 

[djjohnr]

Worth watching the whole thing, but if pressed for time the section starting at 4:00 is particularly relevant.

 

[toodles]

Pretty easy to write your settings down and then section stutters with your rebound and compression full open. Maybe one or two safety clicks of rebound. Lets you seperate spring/chassis harshness from damper config at least.

 

[englertracing]

If the front end is longer, that will accentuate any stiction / flex issues, too, despite the same HA, no?

Yes

 

[englertracing]

You


You still have to push past the low speed compression range to get to the high speed knee. Reduce too much HSC and you’ll reduce support on the really big compressions.

Yes

Worth watching the whole thing, but if pressed for time the section starting at 4:00 is particularly relevant.

Yes

Longer bikes actually need less LSC in my opinion.

 

[bullcrew]

Yes

Yes

Longer bikes actually need less LSC in my opinion.

I'd think I agree with this till a better thought comes along! Lol

Actually I do agree less weight over the front end...I think rake is similar as well...angle has less colum load than a steep head angle so it's not a direct push...soften it a smidge to allow it to start loading.... Higher psi but less initial control of the start

 

[fwp]

Try the Finish line stanchion lube. It may not fix you're issues with setup, but I'm definitely sold. Made a noticeable difference in stiction to me?

 

[ChrisRobin]

There's no stiction in the fork. I have to say, the Boxxer is smoother than my Fox 38.

I finally plugged in my serial number into the RS app and turns out I'm running the fork about 5psi too soft. I'm betting I'm riding into that air spring progression wall.

 

[norbar]

Try the Finish line stanchion lube. It may not fix you're issues with setup, but I'm definitely sold. Made a noticeable difference in stiction to me?

The lube lasts very short imho. The benefits are super slow unless you really love constantly lubricating stuff. No kinkshaming tho.

 

[Jm_]

The lube lasts very short imho. The benefits are super slow unless you really love constantly lubricating stuff. No kinkshaming tho.

Someone really should make a fork where the stanchions/bushings are constantly lubricated by a "bath" of oil. This would be tits.

 

[Jm_]

So I was pleasantly surprised with my Super Deluxe tune today. On those big brake-bumps, you know the dug-out sections, not the little ripples you get on roads, the shock sucked them up very nice like they weren't even there. I totally wasn't expecting it to work so well.

I started with a MM tune, which is way incorrect for the GG. I'm not sure why, possibly availability of the SD or shocks. But anyway, I downloaded some info from Germany, where they lay out a few different tunes. There are a lot of variations, so just because two shocks are MM doesn't mean they are exactly the same, but I followed the guide for the LL, got the right size shimz, got rid of all the dumbass preload rings (there was one in the LL guide), subbing one out with a 17mm shim further back in the stack.

And it was still way too stiff on compression. It was noticably better, a little too slow with HSR still and I figured the compression needed a bit more attention than the rebound.

So I took out that 17mm on the rebound side and took out the 3rd 22mm shim on compression and one of the 18mms and that seems to have had a nice effect. It even seems like I can use LSC without turning it into a jackhammer. Going to have to experiment more with settings, but this is pretty good finally. Running 7 clicks of LSR.

I'm not sure there was any chance in hell of absorbing those braking bumps with the dumbass preloaded stacks that came stock. I mean, it would move, but it's like it's trying to absorb stuff AFTER it's already imparted the damn force on you.

 

[bullcrew]

So I was pleasantly surprised with my Super Deluxe tune today. On those big brake-bumps, you know the dug-out sections, not the little ripples you get on roads, the shock sucked them up very nice like they weren't even there. I totally wasn't expecting it to work so well.

I started with a MM tune, which is way incorrect for the GG. I'm not sure why, possibly availability of the SD or shocks. But anyway, I downloaded some info from Germany, where they lay out a few different tunes. There are a lot of variations, so just because two shocks are MM doesn't mean they are exactly the same, but I followed the guide for the LL, got the right size shimz, got rid of all the dumbass preload rings (there was one in the LL guide), subbing one out with a 17mm shim further back in the stack.

And it was still way too stiff on compression. It was noticably better, a little too slow with HSR still and I figured the compression needed a bit more attention than the rebound.

So I took out that 17mm on the rebound side and took out the 3rd 22mm shim on compression and one of the 18mms and that seems to have had a nice effect. It even seems like I can use LSC without turning it into a jackhammer. Going to have to experiment more with settings, but this is pretty good finally. Running 7 clicks of LSR.

I'm not sure there was any chance in hell of absorbing those braking bumps with the dumbass preloaded stacks that came stock. I mean, it would move, but it's like it's trying to absorb stuff AFTER it's already imparted the damn force on you.

That's got to be badass...love it when it works after putting time into it...especially tuning and shims...

 

[englertracing]

I mean, it would move, but it's like it's trying to absorb stuff AFTER it's already imparted the damn force on you.

Ah yes. The falsehood of the "firm but plush" manifested.

 

[Jm_]

Ah yes. The falsehood of the "firm but plush" manifested.

Platform.

Ever stood on a platform? They are hard as fuk.

 

[norbar]

Someone really should make a fork where the stanchions/bushings are constantly lubricated by a "bath" of oil. This would be tits.

It's good thing no one tried to make a fork with lube forks back in the day and the company name didn't start with mani and ended with poo

 

[fwp]

The lube lasts very short imho. The benefits are super slow unless you really love constantly lubricating stuff. No kinkshaming tho.

Any lubes only work when used consistently.

 

[norbar]

Any lubes only work when used consistently.

As in every 3 runs. My GF would get suspicious if I decided to buy a shipping container worth of lube.

 

[englertracing]

I occasionally wipe the stancions down then apply 5w fork oil, then completely wipe it off.

Smart performance has an article talking about the damage dried mud and even watersspots from washing imparts on a seal

 

[StiHacka]

Isn't the Finish line stanchion lube mostly used for cleaning the seals? That's all I use it for anyway.

 

[toodles]

Isn't the Finish line stanchion lube mostly used for cleaning the seals? That's all I use it for anyway.

First time I've heard of it was in this thread. Any good? I use WPL ForkBoost at the moment for a similar purpose on the my dropper and fork

 

[StiHacka]

First time I've heard of it was in this thread. Any good? I use WPL ForkBoost at the moment for a similar purpose on the my dropper and fork

It's fairly thicc. Apply a bit just above seals, compress the fork a few times, dirt will be trapped in the lube pushed above the seals.

 

[Jm_]

So yeah, wow.

Did a big longer ride in varied terrain today. Climbing up it was not bad, but I was getting some harshness on sharped edged rocks while climbing, you know, the real pointy ones. On a whim, I increased the compression up a bunch, like 5-6 clicks and wow, it started blowing off seamlessly, super supple, but also keeping the bike higher in the travel and stable. This shit was working so well on the DHs that I felt like I had no limit, that I would slam it against whatever I could find and on the janky chunky stuff I could just keep going faster and faster while the bike kept stable and absorbing it all. Real happy with this. It may not be 100%, but for doing it at home, it's damn impressive. It seems like on both the compression and rebound side I'm running some low speed clicks to activate the respective high speed circuits, it's harsher if I run less, but what a freaking difference when those high speed circuits are actually flowing oil, vs shimz keeping them closed or barely allowing any flow. I think I can live with this until I get my coil shock. It's finally "not bad".

I raided the monarch for some parts and interestingly the main piston is exactly the same. No check valve in the monarch tho.

I'm not sure what the LSC circuit looks like exactly in the Super Deluxe, it's got the on/off climb valve thing with the LSC adjuster, I haven't gotten into that. I guess technically there could be a different rebound needle for the LL tune or lighter springs somewhere else, but again, I'm thoroughly impressed.

 

[bullcrew]

So yeah, wow.


View attachment 161884View attachment 161885View attachment 161886

Wow man that view is pretty awesome