alex.martian

I'm newbie here not allowed to add links. I've read wikipedia on suspensions and read for FS problems are (were) bobbing (when pedaling), squat (when braking) and kickback I understood from some video is when rear goes up pedals rotate opposite direction (wiki as error? should be corrected? calls kickback same thing as bobbing).
My main concern is with bobbing, cause I currently use hard tail for both city and some hills riding (and want to switch to FS). Web search for bobbing, anti-bobbing surprisingly for me returned links only for anti-squat. Is bobbing thing of the past and not an issue for modern FS geometry+shock absorbers? Geometry I mean e.g. horst-link, Yeti SB150, Transition.

I understand having pivot point on the level of upper line of chain on the front chainwheel (with 1x12 setup) counters bobbing. Right? But seams to me that is only for middle sprockets gear in the rear (I recall reading about it, but not sure). Why not put pivot even higher to take care of largest one in the rear? What are cons for that? (For that Yeti absorber it pointed forward, to it would rotate down more, but there are many FS with absorbers located vertically like Transition for which I do not immediately see cons).

AdkMtnMonster

The newer geometries help to minimize or eliminate those things, but it’s always a compromise between what the bike excels at and everything else. Meaning that there’s no such thing as the ultimate perfect fs bike that’s best at climbing, descending, spinning, mashing... That’s why there are so many different designs. No single design excels at all facets of mountain biking. There’s always a trade off. Pick the bike that does what you want to do and ride the paint off of it!

alex.martian

Thanx! That much answers first part about how things now.
Maybe I would also get answer to second part too about making even more progress in geometry ;-)

Amendment:
that is why I said I ride both city and hills, bobbing is important (remote lockup could take care of it, but right geometry is more cool). Also, "We brake for nobody" - I have a tendency to save brakes, so squat not so important.

alex.martian

For nobody was a joke, it is a joke in general AFAIK, I recalled it today from Spaceballs sci-fi comedy liked by Elon Musk.
As for me saving brakes, it is true on terrain; on city streets true too, but mostly because I drive slow there, not recklessly. My other (and first) post here was how to make "extra" lower gear ratios.

Darth Lefty 

Brake jack was figured out long ago. Put the brake on the floating link and its force goes tangent to the movement direction and gets spent in the pivots and not in the shock.

The idea of bob and anti-squat is that when the rider pedals, the bike accelerates, and the rider's lagging mass shifts back and compresses the suspension. The counter is to make the suspension stiffen or extend using the pedaling force. Squat used to be more a problem with 3x and 2x systems because the force coming through the chain changed its vector a lot. With a 3x front they'd normally optimize around the middle ring, with the 2x they sometimes took the middle or one ring or the other. But with 1x systems it's much more under control. Some brands dial it right out or over (100%+ anti-squat) but that makes the suspension stiffen under pedaling, so some other brands let it have a little (90% anti) and rely on the shock to damp it. It does change in different rear gears but if you think of the upper run of the chain as a line that you want to aim through the virtual pivot / instant center, moving it two shifts at the rear misses its aim a lot less than moving it one shift at the front, like moving your back hand with a pool cue is a smaller change than moving the hand that's on the table.

Lots more to read here
https://linkagedesign.blogspot.com/

"We Brake For Nobody" is clever, the camera angle keeps close to the ship and keeps turning so you keep going around wide spots that seem like they're going to be the engines, but it keeps going and going...

biker128pedal

Same here looking at a new FS bike. Hard to test ride these days. But yesterday I test road a Rocky Mountain Instinct C70. I was surprised at the lack of bobbing and brake interference. For most of my riding the Element with less travel would be best. After riding the Instinct I’m not so sure. Previously about 8 years ago I rented a Trek. Forget which one but I just remember it was only ok sitting and standing way too much bobbing. New stuff so much better. Now to justify spending over $4k for a carbon frame bike.

prj71

You only live once. No need to justify it.