Suspension performance: Single pivot Vs everything else (a story of kinematics and acronyms)

Ross is safe.

 

I dont think those are dampers, just sliders. Ive been eyeing the sb6 for for my next frame, just a pipe dream these days cuz im po'. I like the geo, not an absurdly long reach like some.
check it, mikie: http://www.pinkbike.com/buysell/2097293/

 

http://linkagedesign.blogspot.com/2016/09/yeti-sb5-carbon-2017.html

Check out the graphs and technical review!!

 

The Yeti Switch and Switch Infinity has been in service for a fairly long time now, and there are no real reports of failures or maintenance issues outside of the ordinary rear suspension - prototypes being the exception. Yeti know what the hell they're doing.

 

They are still extra moving parts that will require lubrication/cleaning/seals/bushngs.

 

Well worth it!

 

Technically, I think it's a moving single pivot. It's a little like a mini link (DW or VPP derivative), but appears to pivot around the bottom link more. All I really know is you must get one. Now.

Maybe this will help you: http://www.pinkbike.com/news/yeti-sb55-review-2016.html

 

It's really interesting, and makes senses because you can SEE the movement in reguards to chainline position In reguards to pivot position.

..... but who cares, tires the real suspension factor.

 

It's not really the suspension, but the execution. Yeti's learned a lot ever since the intro of the SB66 and they've refined their #s so well (at least to my liking), that I would confidently bet they could do this with almost any suspension system/category really--how it ends up looking, is another story. That said, the robustness of having so few bearings and having it all centralized and low is its real strength; its benefit over a single pivot is offset by the added weight and cost. The fully triangulated rear swingarm is a welcomed stiffness boost too. I'm surprised they haven't won more recognition for their line-up, honestly. Seems the biggest critical point is their pricing, followed by no water bottle cage inside the front triangle...

If there's any linkage design I'm interested in, solely for the design itself and not how it was implemented into a production bike, it's the Tantrum Missing Link. This design is likely to start a revolution, once someone seriously invests in it. It's quite mind-opening to me... makes so much sense, that I pray/beg someone with the connections and capital to give it the love it deserves.



The new trend of forward geometry, I believe, is better for people who like high speeds. A forward geometry bike prefers to be pushed, encouraging the rider to be on the gas, but can feel awkward before it gets to that point. I personally fear that it dumbs down the trail a bit much, especially when riding at a group's pace, and leads to higher speeds needed for thrill seekers. That's kind of why I'm warming up to more compact bikes that sort of hit a nice balance. My taste of the E29 and how it just rolls over everything fairly effortlessly made me a bit jaded. Getting on a short wheelbase bike with a bit of twitch was actually a refreshing experience (Ripley). They just complemented each other, as part of quiver. After swinging back and forth between ends of scale, and venturing with 27.5, I've been able to see value in some of the wisdom that more experienced gents have shared with me, which I used to think was just something that applied only to people simply getting/feeling older, or due to nostalgic bias.

That all said, I'll give Yeti's Switch Infinity #1 for now, for those that their current SB bikes are targeted to. I don't say that lightly. That's after doing a lot of analyzing, comparing it against all the respected and popular choices. I'll even put my money behind those words and order up a Yeti and vow to not get another bike for at least 2 years/6000 miles (actually a long time for me, since I like to try to experience new bikes whenever possible). Though, if the Yeti weren't on sale through Comp Cyclist right now, I would've been checking out Canyon or similar bikes due to likely being a better overall value.

With the 5+, I imagine you'll be spending a lot of time dealing with tire grief for a while. Finding exactly the right pressure, and finding the ideal tires for your situation, will be on your mind for quite a while. That, and I don't like the number of bends in the RD cable routing by the BB (adds more friction). All fixable though...

BTW, in the auto world, the term they use for anti-rise, is anti-dive. Not sure why anti-rise or brake squat is what people chose to describe the effect for bikes, but w/e. It used to be countered by the front suspension, but nowadays, with better understanding of the physics, it's handled by manipulating instant centers, in relation to the front tire's contact patch (distance and angle).

 

It's all explained in the various sites that have analyzed my personality type. One example:

http://istp.wikia.com/wiki/Survival_Guide_for_Non-ISTPs

If anyone knows me, I'd like to know how accurate you think some of these sites are. I think it's actually scary how accurate they are... I think these personality tests works well with my type since I don't really let anyone get close enough to influence me to change it; it's likely the opposite for anyone that finds personality tests don't work for them, finding their personality changes each time they take the test (despite claiming to answer truthfully).

It's mainly how I don't value how people can come up with a bold claim or conclusion based on feeling/intuition. That's how many myths/misinformation, which I feel compelled to correct, originate. I value the thought processing of evidence that leads up to a claim, but without that, I fall back on my ability to explain it myself. In this case, the claim of Split Pivot braking well contradicts my findings, as Split Pivot reduces high anti-rise levels that would be typical of a single pivot to get a more active suspension. The rebound being quicker, anti-squat levels being higher, chainstays being shorter, rider positioning being placed more rearward, and excellent traction from tires would be the only way for me to explain the feeling, as I genuinely believe that Split Pivot doesn't deserve any credit for that. I've ridden many diff bikes to try and verify such, to help put together the chunks of info and better understand the bigger picture of how modern mtn bikes work as a system holistically.

 

Oh split pivot, I guess your referring to me. In my line of work we get 2 types of candidates who apply. Analytical intelligent (book smart) and Practical intelligent (experienced) for example. We have a higher turn over rate on analyticals because they can't get past why something should or shouldn't work or try to fix one minutia in an oversize corporate cog.

While I say again, that I respect your insights, it seems to me more rooted in technical manual than technical trails. If you had a blog, I would definitely read it, despite my lack of value to you. Yes, I used emphatic positive words to describe my subjective views, and I understand that could be misconstrued to be bold basely statements. Just to be clear, I place the value of Dave Weagle (patent holder of split pivot) over most people since he has quantifiable work in the bike industry. I'm certain that my lifetime of suspension analysis would pale against 1 month of his workshop tinkerings.

The only true wisdom is in knowing you know nothing. - Socrates

 

Dave Weagle FOR PRESIDENT

 

Not to further derail this thread although I guess I am... I'm grateful for the full range of personalities, opinions, diverse thought and experiences. I also appreciate how we conduct ourselves here. How boring would it be if we all thought the same and we all had the same bike. Variety "is" the spice of life. A forum is the blender that brings it all together. Bikes are the common denominator, but the ingredients are us. Keep the diversity! And keep it coming!

 

If you want a crash course on suspension kinematics, I can vouch for the information published on this site:

http://www.i-tracksuspension.com/suspensiontheory.html

It's the most concisely written material on the subject I've found.

If you're serious about learning and need help understanding, PM me if you have any questions regarding the site's content and the subject. I'll respond to the post, but I'm going to have to pull out of the open discussion, since I'm sensitive to crowds and who I surround myself with. That and I find I'm taking these things too seriously.

BTW, JS-Tuned is likely #2 in my book (more as a complete bike design, than rear susp design), especially after experiencing the Spider 275c and Primer. The execution of the geometry, the custom tuned shock and everything else felt extremely dialed. The balance of even the bike's weight itself, was well centered. The latest gen of VPP is not the same, nor are the prior gen Intense bikes. One thing to note is how I find it so easy to corner well on Intense bikes in general. That and the level of damping (carbon, XMC 1200 wheels, shock, and fork) smooths out the ground noticeably well, to the point I wonder if some might find it excessive (dull/dead feeling).

 

@Varaxis there is no need to leave, but you have to deal with those of us who are not wired like you to dive into all of the complicated details of opposing forces.

Here's how suspension kinematics and research works for me. The manufacturer does the work - engineering, design, fabrication and assembly. Their marketing department describes how bitchin' and superior their suspension system is (with clever acronym) and how it climbs like an xc race machine and descends like a DH bike. Then I demo one. If I like it and if I'm in the market for a bike, and it's the right price, I buy it. If not on any of those counts, I don't. Not really sure I need to know about instant center, anti-squat, rising rate, falling rate, axle path, etc. I just need to know how it rides for me on the most challenging trails I ride. Fortunately, I can also tune suspension to get the best out of the design (and the shock) - for me.

I dig that your well-researched opinion landed on Yeti as the best example of modern mtb rear suspension. I will forward this thread to Chris Conroy, president of Yeti. He will enjoy it.

 

I use the information to verify why I liked one bike better than another. I answer questions such as:

Why do I use up travel so easily one one bike vs another, without resorting to simple answers like, "just make it more progressive (add spacers) if you're using full travel too often". (E29)

Why does this bike kill my knees to pedal it, without resorting to simple answers like, "its seat tube angle is too slack." (Evil Following)

Why does this bike feel more playful than this other one, without resorting to simple answers like, "its chainstay length is short." (Ripley, def doesn't have short CS)

All those simple answers proved to be poor answers in each of the examples. It allows me to make more informed decisions in the future. I used to go by the saying, "trust, but verify," but now I'm turning to being choosy in whom I trust, but still verifying.

FYI, a new Vorsprung Corset-like aircan worked far better than adding spacers to the positive chamber for more ramp up, despite the leverage ratio being flat-linear (adding spacers made the early and mid-stroke more wallowy). Sensitivity to kickback caused knee issues. And lack of damping (more bounciness, including more tire pressure), and short wheelbase was the reason for playfulness.

 

I am fairly obsessed with geometry myself. Far more than suspension kinematics.

 

@Varaxis ,
Thanks for the Yeti input. I'm thrilled like a Yeti fan would be. I trusted their marketing when I tried their ASR5. Verified it by test driving one for a week. Loved it and bought one.

It took a while for me to "get" you as I'm sure you will recall. Varaxis and I had many PM conversations back in STR days. You won me over back then. I trust your facts and research. Every forum should have a Varaxis in my opinion, it adds to the successful blend of debate, information, and mind expansion.

So now I will comadier a Yeti SB5 to test ride to see if once again Yeti can earn my business. I suspect they will.
Stay you Varaxis, and please do not be a stranger on imtbtrails. Let's ride again soon!

Mikie

 

@Varaxis, I am interested if you could verify my experience of an SC Bronson verse an IBIS HD3.

My personal riding experience was that with the HD3, on decents and rolling terrain, I could keep a fairy neutral riding position, even on semi rough terrain I did not need to keep my butt way far back. I could stay in the cockpit more without getting bucked. And getting the front wheel to lift over obstacles was effortless. Generally it handled very intuitively, with little fore/aft body shift to handle obstacles.(similar on mojo 3)

My personal experience with the SC Bronson is that I needed to shift my body around much more to overcome obstacles that required front wheel elevation. And the fore/aft body weight shifts needed to be much more pronounced verses the HD3 to get a lively active feel. Still on the fence about whether this was good or bad, or just different.

Both bikes ploughed through all sorts of terrain seated and neutral just fine, but Bronson defiantly needed more effort from me to get it really jamming. Whereas the HB3 could be ridden seated and neutral and work fantastically without much thought of pre planning attacks on obstacles

Of course we cannot rule out all the contributing factors to my experience, but I am pretty sure that the kinematics are different enough that riding style adaptations needs to be made to each bike to take advantage of all of the suspension design features.

 

@Varaxis, dont suppose you know the difference between the blue vs green line son pedal kickback graphs?

 

Who?

 

That guy who just wizzed by everyone like they are trackstanding.

 

On the ebike?

 

Oh does he not post here anymore?

 

I haven't seen him here in quite a while. I know (or I hear) he frequents MTBR.

 

i don't think we are stimulating enough

 

'Raxis don't surf.

 

Holy thread resurrection, Gary!

Varaxis hated my reliance on "feel" as opposed to data to evaluate equipment. HATED it! Everything is quantifiable and provable in the Varaxis world view. That's why I found him to be so valuable - I have never met anybody so extremely based in Realist philosophy (external tests of truth - empiricism and quantifiable data). Existentialists such as myself drive Realists crazy, and vice versa.

 

Oddly enough, in the mountain biking world, our "feel" is the biggest data point in the schema. 2 identical riders who have the same height, weight, arm span, power output, etc. can have 2 drastically different views on a bike based on ride stance and overall feel. In any other mechanical sport, whether by cars, planes, boats or motorbike, our mass is just a small component in the overall machine. However, in a 20-28 lbs bike, we are the machine and the how the bike trails is largely dependent on how we pedal. Our weight shifts constantly which always affects the head angles. tire profile, sag, shock tune.

Just my 2cents