[Udi]

I've noticed there's a significant variation in how much sag people run, and different frames seem to call for different numbers too - so I thought it'd be fun to get some sample data.

Frame/Shock:
Rear Sag %:
Sag measured with riding gear?:
Sag measured standing/sitting?:
Thoughts: (is it perfect, or have you been thinking about going to a firmer/softer spring rate?)

Optionally also list front sag %, I left it out because I feel it is difficult to measure accurately and reliably, but include if you have it.

 

[ALEXIS_DH]

scott gambler dh10 2010, fox dhx 5.
sag: 3" (out of 9.5")
sag meassured with full riding gear.

thoughts.... i run 150psi, chamber open all the way, no propedal.... for full blown downhill, I´d ride a softer spring.... but since this is my do it all bike and I go around town for 20 mile rides.... my current setup is acceptable.

 

[cecil]

2012 demo
Fox van r with 500lb spring
25% sag with gear
I'm 225# with gear
Measured with rear wheel up on one step in typical standing position

Girlfriend
1976 5'1" 105#blonde
0% sag at the a$$
0% sag at the tits

 

[norbar]

2010 Banshee Legend with RC4
Was 40% with gear and it was bad. Lower bb was awesome for cornering but I didn't like how the susp felt.
Now 32% with gear and it's perfect.

Front sag - closer to 20% than 25%. Feels better that way. Tried 15% but lost a lot of traction in that setting.

 

[PsyCro]

Corsair Crown , Roco WC low leverage tune and 5wt oil.. very linear suspension

Running the 10.5" shock @ 200mm travel 26% sag (250lb spring)
.. great with a SC fork for poppy fun riding, works out well with the linear suspension.. usually this isn't enough sag for me on more progressive designs.

Running the 10.5" shock @ 230mm travel 31% sag (250lb spring)
.. great for harsher DH/FR.. still poppy enough but absorbs bumps pretty darn well.

Running the 10.5" shock + blow off shock @ 250mm travel with 40% sag (150lb spring)
.. great for all out chunder and steeps.. need this much sag for the suspension to work properly, and it works.

The 888 up front with about 20% sag and compression depending... the 66 about the same.

Sag measured while sitting for rear, standing for front suspension. Sag is obviously VERY rider and bike dependent. Find wachya like, and ride it!!

 

[staike]

Mondraker Summum 2011
888 EVO Ti with Medium spring
CCDB coil with 250 lbs ti spring
143 lbs / 65 kg with gear

Around 20% sag up front with preload wound halfway in. Standing.
42% sag on the shock with some preload. Sitting.

Waiting for a 275 spring to get the sag in the 35-38% range. The bike is designed around 40% sag, but it feels too soft and unbalanced now.

 

[supercow]

Frame/Shock: Morewood Makulu 2013, BOS VOID air
Rear Sag %: 35%
Sag measured with riding gear?: With gear
Sag measured standing/sitting?: Sitting
Thoughts: (is it perfect, or have you been thinking about going to a firmer/softer spring rate?): Perfect.

 

[Chridi]

Frame/Shock: Rocky Mountain Flatline WC (straight tubes) / CCDB
Rear Sag %: 31
Sag measured with riding gear?: w/ gear
Sag measured standing/sitting?: standing
Fork: Fox 40 '09
Front Sag %: 18
Thoughts: Rear is fine. Testing a heavier fork spring (15%) the coming season.
_______________________

former bike:
Frame/Shock: Turner DHR (round tube), RS Vivid coil
Rear Sag %: 33
Sag measured with riding gear?: w/ gear
Sag measured standing/sitting?: standing
Fork: Boxxer WC '08
Front Sag %: 19
Thoughts: Perfect.

 

[DMdh]

Frame/Shock: IH sunday ´08
Rear Sag %: 30 %
Sag measured with riding gear?: w/ gear
Sag measured standing/sitting?: sitting
Fork: Boxxer race 2010
Front Sag %: +- 23%
Thoughts:

 

[HardtailHack]

Frame/Shock: Nicolai ION, Swinger 4 Way or Bos Stoy.
Rear Sag %:Lots when I'm fat not so much when I'm not so fat
Sag measured with riding gear?:Shoes and a helmet make no difference at 220LB
Sag measured standing/sitting?:Standing, sitting is silly.
Thoughts: (is it perfect, or have you been thinking about going to a firmer/softer spring rate?)[/B] Swap regaularly depending on my fatness/how many rocks I clip.

 

[no skid marks]

Girlfriend
1976 5'1" 105#blonde
0% sag at the a$$
0% sag at the tits

76 model without sag up top. Got some upgrades or just running low speck? Shiney stuff fades quicker, so low specs okay by me

I tend to have to gently ride the bike to get a decent sag reading. I think at under 70kg, stiction and lazy head angle seem to play a big part in the reading.
I was running 30+ out back, but am now on a heavier spring on new bike while I wait for another shock. Feels good on jumps, drops, smooth but big stuff. But a bit less plush in the rough. About to get an air shock(not sure why I was fool to try again), at least they're good for playing with sag. Mix n match to suit tracks easy. I'll spring the coil shock to match the sag I like with the air, and use the coil for rocky longer tracks. I do like the docile feel of the air shock on certain tracks.
Front is hard to get a accurate reading at my weight, even with freshly lubbed forks. But I seem to only use about 90% of travel max most of the time. Sorry for the vague reply.
Edit:- Sorry forgot template.
Frame/Shock: Zerode G2/Vivid rebound adjust only, Glory tune. Bos Air coming.
Rear Sag %: 25% at present, will go more.
Sag measured with riding gear?:Yep
Sag measured standing/sitting?:gentle rolling standing without breaking.
Thoughts: See above.
I'll match rear to front travel as my main guide for most instances.

 

[kidwoo]

A rough guide, just to get you started.

 

[Bikael Molton]

I approve

 

[tabletop84]

Tues 2.0/CCDB:
Rear Sag %: 33
Sag measured with riding gear?: w/ gear
Sag measured standing/sitting?: standing
Fork: 888 Evo Ti 2012
Front Sag %: 27
Thoughts: Will try a 250lbs spring (now 222)

 

[Mo(n)arch]

Currently Trek Session 88 first gen (2009):
Last year:
SAG measured standing, with gear.
Rear: 30%, 500 lbs spring, 175 psi can halfway closed (DHX 5.0)
Front: 888 Evo, about 15-20% SAG, progression wound out completely.

I thought it was a pretty decent setup for fast DH tracks. Yesterday I went for the first ride of the year on a really technical, rocky and rough track and it was a bit of a PITA. I have to admit that I lost alot of strength over the winter and it showed big time. Lots of work to do now...

 

[Gary]

so I thought it'd be fun to get some sample data.

Think someone needs to get out of the lab and do some riding to re-calibrate his fun-meter

But just to oblige..

Frame/Shock: every full suspension frame I've ever owned (from 1995-present)
Rear Sag %: 35-40%
Sag measured with riding gear?: sort of.. I weigh the same in civies as riding gear.
Sag measured standing/sitting?: standing, if you measure it seated you're problably better off with a WSD saddle and a suspension seatpost than rear suspension.
Thoughts: (is it perfect, or have you been thinking about going to a firmer/softer spring rate?) it's awesome! (would need to go stiffer if I was a pedaller, rock garden plower or liked harsh landings)

Optionally also list front sag %, I left it out because I feel it is difficult to measure accurately and reliably, but include if you have it.15-20% (I ride a stiff 100mm DJ hardtail far too much so absolutely hate soft/wallowy forks)

 

[boylagz]

Frame/Shock: 2011 V10c, CCDB + 400#, 170 lbs kitted
Rear Sag %: 33ish
Sag measured with riding gear?: Yes
Sag measured standing/sitting?: Standing
Thoughts: I love this setting for everyday riding. Still a lil tweaking on the shock but so far its been amazing. For the ccdb base setting I sped up LSR by 6 clicks. Baseline compression settings are feeling good so far. I need to lose weight though...

Didnt measure fork sag. I have a 2013 Van 180 rc2 with the stiff(green?) spring.

 

[msaman]

frame -IH Sunday with RC4 with 350 lbs
I am 70kg (155 lbs) with gear
25% sag with riding gear -rear
standing ofc
20% sag on the forks
I feel it perfect now ,if I ride a bit slow over rocks or roots it's a bit harsh but that's why I am trying to go faster over such things

 

[csermonet]

For sake of staying on topic

DW DHR, size large, RC4 with 400lb spring
170lbs no gear, 180ish in gear
~27% sag with gear
25% sag in font, Fox 40 with green ti

Very happy with setup no plans on changing. Gotten a little more ambitious with turning my dials and trying to understand suspension setup a bit more, proved to be worthwhile.

Udi - Have an unrelated request/question, tried to pm you to avoid doing this or starting a thread but your inbox is full.

 

[Udi]

Some interesting responses here, I'm surprised by how much front sag a few are running (27% tabletop84?!) but I presume some of that is to do with measurement accuracy / standing over the front more than others.

csermonet -
I cleared some inbox space, but I presume it was just the hub you wanted to ask about?

 

[tabletop84]

Well that's what I get with the standard-ti spring (maybe a bit less) and I don't like running too much preload because it can damage the spring. But travel usage and performance is ok for me as I'm a light rider (~ 160lbs/w gear). All references that I find mention at least 25-30% sag for dh but I will try a stiffer shimstack and a harder spring in the shock this season.

 

[Udi]

Yeah fair enough.
25-33% is for the rear, when checking sag on flat ground the front should generally be 10-15% less than the rear because because weight transfers forward a lot when you're actually pointing down the hill. I think a firmer spring in the shock without a firmer spring in the fork would probably be a bad idea as it would cause an even stronger forward weight bias (encouraging diving of front / going OTB) especially on steep tracks.

 

[Udi]

2010 Banshee Legend with RC4
Was 40% with gear and it was bad. Lower bb was awesome for cornering but I didn't like how the susp felt.
Now 32% with gear and it's perfect.

I had a similar experience a few years ago when running ~38% sag, it honestly didn't even feel faster cornering because the setup was possibly robbing front traction, and I was constantly hitting things with my pedals / guide or worried about hitting things with them. Reduced to ~32% and it was much better, more confidence in rough terrain, and more weight on the front wheel in corners.

 

[tabletop84]

Yeah fair enough.
25-33% is for the rear, when checking sag on flat ground the front should generally be 10-15% less than the rear because because weight transfers forward a lot when you're actually pointing down the hill. I think a firmer spring in the shock without a firmer spring in the fork would probably be a bad idea as it would cause an even stronger forward weight bias (encouraging diving of front / going OTB) especially on steep tracks.

I think measuring sag in a static setting is not enough. When I ride the bike I can feel better if the bike feels balanced or not and the rear shock felt a little to soft. Front is fine i don't think the fork dives too much. I can counter that with lsc but maybe the hsc-mod makes things better. With air forks it's another sotry: when I put enough air in it to not dive like crazy I don't use full travel and when I use less air to get full travel I can't compensate the diving with daming as the fork would become harsh on high sepeed chatter.

 

[Udi]

Fair call, dynamic sag definitely matters more, and I found the same thing with air forks - however my preference in general with forks (air or coil) is to have them provide support and absorb bumps in the way I want, with full travel usage as a much less critical concern.

Like you I found it much easier to find a good balance of those things on a coil fork (and consider them a superior setup), however perhaps more modern / future air forks will be better in this respect and make the performance gap smaller.

 

[tabletop84]

I doubt it. Revelation, totem boxxer every time I was like "fuu front end where are you going" entering a steep section with the air-version of the fork. Now I have a suntour durolux which uses a air spring backed up by a light coil spring and I hoped it would be a bit better but nah as soon as the first steep sections appears the fork sinks down almost to full travel. Damping or more air can compensate it a bit but it just don't feels the same as with a coil equivalent. And then the weight advantage is neglegible with titanium springs and in dh it's even more negligible. I heard a few people say that the idylle rare air would be as good or even better as the coil version but then how many people ride this fork. But I might to get to ride on soon.

 

[Udi]

That's because the air spring curves in the forks you rode aren't particularly great. Making them linear isn't rocket science, but most manufacturers seem to struggle with it. Once you do that however, the behaviour of the actual spring is not very different to a coil - and those dive issues disappear.

The only problems you are left with then are the extra friction from the air seals, and any heat related spring rate increase issues (both nonexistent with coil). However a) this is a much smaller issue in a fork due to the higher volume, and b) I think as air springs become more common (which seems to be happening whether we like it or not), seal / piston design will improve and reduce frictional issues to a reasonable extent, at least in forks.

I have no desire to ride anything other than a coil either at this stage, but I had a brief ride on the new 40 RAD and I think it has potential. A little more friction than the coil version, same story on the Idylle Rare Air I rode (carpark only, but enough to gauge seal friction). Perhaps after 2-3 years of further development these forks will be closer to coil in performance.

 

[tabletop84]

Friction is a non-issue with my revelation dual air. Is as smooth as my 888. But an air spirng does behave differently on a molecular basis when compressed and therefore it always will sink deeper into its travel under certain circumstances. You can compensate it but maybe to a point where it's not noticeable to the average rider (me) but for now it's always a compromise.

What this guy did was basically enlargind the air-chamber of the totem when it gets compressed so the damper curve got more linear (second graph) but you can see that it's not as linear as a coil spring and the wieght gain compared to a ti-spring is probably minimal:

http://www.mtb-news.de/forum/showpost.php?p=9094359&postcount=1060

 

[Udi]

You've got the wrong idea. The reason an air spring behaves differently in general has less to do with the molecular structure of air itself, and much more do with air spring design and its resultant rate - which on most products follows a regressive-progressive curve. This is why you end up with a fork that feels harsh initially / has poor traction, and struggles to use all its travel, however still dives a lot in the middle of the stroke as well.

The rate curve is a result of the pressure acting on either side of the piston, and the way the volume of the chamber behind each side of the piston (positive and negative) change as the suspension component moves through its travel.

The molecular effects of air may come into play when considering other factors like heat generated during compression over the period of a run etc, but I don't think this is a huge consideration on a fork which has quite a high volume of air. What you describe points purely to a spring rate curve issue in my experience, and has been the classic problem with air suspension for a long time now.

For whatever its worth, I too currently own a revelation dual air, and have owned totem and boxxer solo airs in the past. They are not as smooth as an 888 by any stroke of the imagination, but perhaps yours is magical.

 

[Udi]

The second graph in your link illustrates my point. For it to function and feel like a coil (friction aside), the rate has to *match* the linear coil spring, which isn't true in that case. Your comparisons are based on products that do not have a linear air spring - which is why they do those things you don't like.

If you ignore the marketing curve by specialized there, the orange line shows an exaggerated example of what I'm saying. The average air spring curve starts off firm (due to having to break past the upwards force that holds the suspension at 0 travel, not necessary on a coil spring), falls away in the middle due to the changing relationship between the negative and positive air chambers (both pressure and size), and ramps up quite firmly at the end due to the minimal volume and high pressure. The curve shape is a result of the air spring design, not air itself.

My point is, if you engineer an air spring curve that is *actually* linear (none of the products you mentioned), you can essentially replicate the performance of a coil spring. This is entirely possible even though not many (if any) manufacturers have implemented it.

The things that will be hard to replicate are friction (n+>=1 sliding seals in air suspension vs. coil = higher friction) and consistency due to molecular characteristics of air (less of an issue in a low pressure + high volume fork, but a problem in rear shocks). The characteristics you describe (especially the mid-stroke wallow) are a common result of poor spring rate curves, not consistency issues.

 

[tabletop84]

But the question is how much it will be lighter. If I throw out the whole air- and travel adjust unit and put a Mz55-ti spring in there I doubt I would gain any weight. (ok ta is nice on steep ascends)

And the revelation is really smooth maybe its the engine oil and stendec-lubrication but I also suspect slightly loose bushings but definitely impressive for an air fork.

 

[Udi]

Not much! I totally agree with you on that front, however there seems to be some current craze for air suspension and I feel like it's inevitable that most / all brands will switch to it eventually.

 

[chup29]

bored and cant study for midterms any more so i thought id chime in...

Frame/Shock: 2010 Intense M9 with a cane creek double barrel, 2013 Carbon Antidote Lifeline with a cane creek double barrel
Rear Sag %: 15%-20%
Sag measured standing/sitting?: standing
Thoughts: (is it perfect, or have you been thinking about going to a firmer/softer spring rate?) it's perfect, the cane creek is sensitive enough that i dont lose any traction and my bikes dont feel wallowy at all. i run my bikes extremely low and slack (63ha and a 13.5bb) and the stiffness of the front/rear holds the geometry really well so the bike is always composed and balanced. Also pedals great and the stiff suspension means i carry incredible speed without really trying which is pretty nice - with that being said, you have to be a pretty good rider to make a super stiff setup like this work for you, if i rode this setup during my grom years, i wouldnt be able to control it - now the more aggressive i ride, the faster i go.
Optionally also list front sag %: spent yeeeaaaarrs dialing in my boxxer world cup to feel just perfect, i run it with almost no sag, its like 5-10% - i run the low speed compression close to maxed so the fork is almost locked while pedalling, normal air pressure and very little high speed compression with the bottom out maxed so the air spring is super progressive - it basically means my fork is stiff under power, opens up for a bump and soaks up everything without feeling wallowy and it almost never bottoms out

 

[fred.r]

Blah blah blah, less smart more fart.
Evil Undead/2013 Fox DHX RC4
28%
Gear on
Standing (although I tend to sit while riding down most tracks)
Still fiddling, spring rate is fine, just playing with pre-load, LSC and pressure
Fork is somewhere under 20% but not by much

 

[Udi]

bored and cant study for midterms any more so i thought id chime in...

That's the sort of crazy setup I was hoping to see out of this.

Do you find the bike is difficult to ride when you're having an off day / not 100% on your game? Surely there would be significant harshness running less than 20% R / 10% F - I'd actually be more concerned about the front, especially given the boxxer WC's general reluctance to move freely at the beginning of stroke compared to most coil forks. I've ridden a setup very similar to this (not my bike, V10C with a BWC setup fairly similar to yours) and I found front traction on loose off-camber corners was the biggest issue - but that may not be a common scenario on every track.

How does the rearend handle deep / fast square edged hits, particularly consecutive - for example a set of rock ledges?

What tyre pressures are you running, and if you don't mind answering, what sort of level do you ride / race at? Any kind of description is fine. Maybe even some examples of the types of tracks / terrain you ride on?

 

[chup29]

That's the sort of crazy setup I was hoping to see out of this.

Do you find the bike is difficult to ride when you're having an off day / not 100% on your game? Surely there would be significant harshness running less than 20% R / 10% F - I'd actually be more concerned about the front, especially given the boxxer WC's general reluctance to move freely at the beginning of stroke compared to most coil forks. I've ridden a setup very similar to this (not my bike, V10C with a BWC setup fairly similar to yours) and I found front traction on loose off-camber corners was the biggest issue - but that may not be a common scenario on every track.

How does the rearend handle deep / fast square edged hits, particularly consecutive - for example a set of rock ledges?

What tyre pressures are you running, and if you don't mind answering, what sort of level do you ride / race at? Any kind of description is fine. Maybe even some examples of the types of tracks / terrain you ride on?

last year i ended up as the #2 ranked expert 19-29 racer in the country (im 21) despite spending most of my summer race season crashing and getting 10th, did that at like 4 races haha

i live in ashland oregon, grew up in palo alto california and go to college in boulder colorado so the bike sees a ton of different terrain, i prefer the ashland tracks - the most amazing trails ive ever ridden are hidden away up there, its the most fun ive ever had on a bike - 5000 feet of elevation drop and 12+ miles of trails on the way down, most are just smooth fast corners - in colorado everything i ride is super steep, rocky and very gnarly and in california its closer to the ashland style but with less good corners and way more jumps.

the bike requires you to get super aggressive to get the max but if i find that more and more i spend my time dicking around and not pedalling or trying too hard and even when i do that, i still coast fast and carry good speed over stuff so im never really going too slowly, even on an off day. its definitely more comfortable at speed, the faster you go the easier it is to ride but the sensitivity of the cane creek is incredible so it never feels uncomfortable, im 200 pounds and my 130 pound friends can usually ride my bike without issue. ive also found that the faster i get, the more i slow down the rebound and stiffen the suspension - i started out on a gooey pogostick and now its stiff and very balanced and controlled, id probably say its medium fast rebound right now and that really helped me with the square edge hits and continuous hits. With my riding style i spend more of my time hopping over the bumps and pumping every downslope i can find then hitting stuff and plowing straight through, im way more into the sneaky sam hill lines haha. as for the boxxer, i dont really notice too many weaknesses in its performance, it will slide on the loose long off camber stuff but with how slack the head angle is, you can just pull it back no problem. since i run slightly low to normal air pressure and then just max the bottom out and low speed, it stays high in its travel but is pretty sensitive to the small stuff, it tracks really really well, i also got good and getting over the front for loose sketchy stuff so that might play into it.

as for tires and tire pressures, i run exo minions on the front with an all mountain tube and either an exo high roller 2 or a normal high roller 2 with a dh tube in the rear (i pick up the front over most of the sharp stuff and try to always pick smooth lines so i rarely flat in the front despite being 200 pounds) - tire pressures are usually around 27psi in the front and 30psi in the rear, maybe a little higher, if you pinch the tire as hard as you can you get just less than a half inch of sidewall movement

hope this helps!!

 

[Uncle Cliffy]

Frame/Shock: Intense M9. CCDB coil. (Changing to a RC4 with AVY Advantage rebuild soon)
Rear Sag %: 33% on the dot.
Sag measured with riding gear?: Yes
Sag measured standing/sitting?: Standing
Thoughts: (is it perfect, or have you been thinking about going to a firmer/softer spring rate?): I just ordered a 500lb spring for a backup, even though this setting is supposed to be perfect.

Running the bike at 9.5 travel in the middle progression hole. I'm going to try the RC4 since I've never been completely happy with the CCDB. The bike rides well enough for my taste, but no matter what I do the square edge performance isn't what I think it should be. I've tried various settings of compression. Haven't taken the time to talk to Malcolm about it, but for the M9 I've seen lots of similar reports. I'm also hoping to get a more lively feel out of the bike after I talk to Craig about valving.

That's the sort of crazy setup I was hoping to see out of this.

Why am I not surprised...

 

[SCARY]

I talked with Gwins mechanic at the Bootleg Canyon race over the weekend.He was saying that Troy Brosnan is running 20% sag in the rear and Gwin was just a little more.I also asked him if Gwin had changed any geo on it and he said no,and that he really liked the short rear on it and how it kinda "fell"into corners.And the bike weighs about 37lbs.All typical questions that a noob would ask.So, I really stepped up

 

[staike]

Gwin was running a 500 lbs spring on his Session, that shouldn't be a lot out of the norm for his weight. Weird if he suddenly changed to running a lot less sag.

 

[SCARY]

I don't know how transferable spring weights are to suspension designs.Im 200 and run a 400 on an M9.i dunno