[Closed] Quad-4 Suspension pros and cons?

Nobody? Must just be magic then 🙂 People seem to like the way they ride, which is obviously what matters but (other than a vague reference to it being similar to FSR), I can't find any details on how the Quad 4 design compares with other well known designs.

It's just another true four bar design. How it behaves totally depends on the pivot positions - it could be very efficient, very active or somewhere in between. It could have a progressive or regressive rate or a mix. Unfortunately I haven't seen any models showing how they chose to balance the compromises.

Thanks chief. I always thought that a true four bar had to look like this though:

[img] [/img]

I take your point that the devil is in the details though, which is why it's so frustrating that they never give you the details. Just vague marketing guff about how it's designed to be super efficient and super active and would you like to buy some beans?

Details of different suspension designs [url= http://en.wikipedia.org/wiki/Bicycle_suspension#Rear_suspension ]here[/url] but 4-bars don't have to look like the picture you posted, as the suspension can be linked to the frame (via the shock) without one of the 'bars' having a pivot half way along.

There are four-bars and four-bars...like all suspension designs, minor changes in the placement of the main pivot will have a profound effect on the suspension characteristics. Specialized's interpretation has subtly changed over the years, my 2004 Enduro has a main pivot positioned at roughly two o'clock in relation to the bottom bracket. My 2010 Camber and 2014 Stumpy has a main pivot positioned right above the bottom bracket, a very small revision but there is a huge difference in the feel of the bikes.

Although a Whyte, a Specialized, a Canyon and a YT all superficially share the same layout the devil is in the detail, remember that each manufacturer will have their own ideas on the most efficient wheel path.

Thanks. So Quad-4 is a type of Horst/FSR design, but the main pivot is behind the bottom bracket (more like 10 o'clock than 2 o'clock), so all bests are off 🙂

Suspension - its all BS. Its a spring attached to a wheel. You don't see motorbikes farting around with imaginary pivot points.

Filter out bikes that have the right geometry, travel, wheel size for your needs.
Tailor your material and spec to your budget.
Cross off the bikes that will fall apart (e.g. Mondraker etc)
Choose the one you like the look of.

simples

That's it, in a nutshell...your best course of action is to test ride as many bikes as you can and make a decision based on what works best for you.

Suspension - its all BS. Its a spring attached to a wheel. You don't see motorbikes farting around with imaginary pivot points.

They would if they were powered by a bloody great single cylinder super low revving really low horsepower engine perched loosely on top of the saddle!

Suspension - its all BS. Its a spring attached to a wheel. You don't see motorbikes farting around with imaginary pivot points.

Well, sort of. It's a very different setup - not least because the engine is far more powerful, and isn't moving around on the motorbike all the time, for starters. The imaginary pivot malarkey isn't needed because there's more space and more power available on a motorbike. If it was just a spring attached to a wheel, we'd all be riding Raleigh Activators. 😀

Three basic types of motorcycle suspension detailed here: [url= http://www.carbibles.com/suspension_bible_bikes.html ]http://www.carbibles.com/suspension_bible_bikes.html[/url]

More on chassis dynamics:

[url= http://bienvillestudios.com/index.php/chassis-dynamics/ ]http://bienvillestudios.com/index.php/chassis-dynamics/[/url]

FWIW, I've always either ridden single pivot or linkage-actuated single pivot rear suspension designs. Each one feels different. I've just bought a FSR / Mcpherson strut / fourbar / Horst link frame - a Whyte, as it happens - and it definitely rides very differently compared to my last FS bike, an Orange 5.
To get back to the initial question in this thread, yes, Quad4 seems to be rather good. I'm going to swap the 34t ring I boshed on the front and go for either a 32t 1x10 or a 2x10, however, as the bike remains active when pedalling squares up climbs a lot more, when my old single pivot bikes (and there've been a few) stiffened under pedalling load a lot more.

HTH.

Thanks bent. What about on the way down? How does it react under braking?

I also wonder how sensitive it is to chainring size. Would switching from a 32T to a 28T, for example, make a noticeable difference (as it does with SP) of are these designs inherently less sensitive to chainring size?

Roverpig, it's lovely and active when descending, and when braking. Even with the shock lockout accidentally left on. 😳

Short answer: I need to spend more time on the bike to give you an honest answer. One thing about single pivot is that, generally, you get some sort of suspension stiffening when there's load on the chain. With a four bar it (in theory) stays supple, so clumsy gert mashing on the pedals results in bobbing.

Rear end braking downhill: I always favour the front brake downhill anyway, and I was riding with a Racing Ralph on the back that was woefully under-inflated for a key bit of the ride, and fairly grip-free on another (rather greasy, wet-chalk) bit of the ride which contained a couple of downhill sections I benchmark on. Bear in mind I've been riding a 29er HT exclusively for the last year or so, with the exception of a brief squizz on an oversized Transition Bandit 29.

One thing I noticed was that I didn't get full front or rear travel on my first ride (Although I did get a ton of Strava PRs - unsurprising given I've only ridden offroad with Strava on a HT 29), despite setting sag correctly. One of the reviews I read suggested pulling out a couple of volume spacers in the Monarch rear shock. Front needs work, too - possibly too much threshold, or brand new seals causing a bit more stiction.

Have some geeky reading: http://linkagedesign.blogspot.co.uk/search/label/Whyte%20Cycles

Google translate does help it make more sense unless you're a much better linguist than I! 😉

Ooh - that looks good! The translation is a bit painful, though. Is he saying 2x10 is a better bet with this design than 1x10? I'm edging towards that conclusion too, by the way.

Comparing those numbers with the ones on the current Orange thread (and assuming they mean the same thing) there seems to be a lot less anti-squat with this design than with my Five (where the numbers are always above 100%), so I guess that would mean that it should bob more on the climbs. Of course, in practice, you may just need a bit more platform on the shock to produce the same feeling.

The conclusion that it works better with 2x10 than 1x10/11 doesn't bode well for the new SCR models, but whose to say that they haven't tweaked the design for those models anyway.

bent udder, which Whyte did you get? I picked up a G150S last weekend and the shop set the suspension up with 100 psi in the front and 220 psi in the back, which upon further reading sounds somewhat high (I weigh around 85kg suited and booted).

I didn't really notice the rear suspension (coming from a hardtail, I have a lot of riding to do before I can go around making informed judgements on that), but the front did not seem as wonderful as it ought to have been (even accounting for the relatively tame wilds of Hertfordshire).

Ooh - that looks good! The translation is a bit painful, though. Is he saying 2x10 is a better bet with this design than 1x10? I'm edging towards that conclusion too, by the way.

Yes it is - here's my google translate improvement tips for Spanish to English when reading about bikes

Pod = Chainstay
Dish or Plate = Chainring
Buffer = Shock
Blocking = Platform damping?
Cushion = Spring
Box = Frame

😉

Yes, he's saying 2x10 better than 1x10 with that frame.

A few years ago I looked at the different suspensions designs as part of a self build project. I tried to 'research' which was best by reading all the magazine reviews I could find (I was young and innocent!).

The conclusion was that every design was the best ever, made the hills come alive etc.

In the end I did a Quad four bar linkage, because the links could be fairly short and possible (for me) to machine from a smallish block of Al.

Yes it is - here's my google translate improvement tips for Spanish to English

Btw you know you can contribute improved translations to Google Translate and help make it better.. ?

Ninja, it's a second hand '13 T129, 16". Can't remember the pressures I used, as I just set it up for 25% static sag for starters and will adjust from there. RS forks tend to have rather high pressure settings for weight, by the way.

[edit] how much movement were you getting out of each end? There should be travel indicators (basically small red rubber bands) on the rear shock and one fork leg. As a rough guide, you should be getting full travel on each end at least once per ride on your usual terrain.[/edit]

I got about a third out of the front, and between half and two thirds out of the back. However the terrain was absolutely not a fair test, far too gentle.

My next chance to ride isn't for a couple of weeks, so I'm going to check the sag before then, probably let some air out of the fork, head to Swinley Forest and see what happens.

My train of thought is mainly based off the fact that the RockShox guide says I should be running up to 25 psi less, and that a totally unscientific bounce test has the fork feeling pretty darned firm.

Ninj, My previous experience with recent RS fork pressures is that they tend to be a bit too firm, so it sounds like you're on the right track. If the forks are Solo Air, then it's just one pressure you need to set. If not - if there is a second valve at the bottom of one fork leg - then you need to set the Negative as well as the Positive air pressures.
By the way - that's a tidy looking bike!

Cheers, it's my one bike to rule them all! Apart from the road bike obviously...

The forks are Solo Air, so just the one pressure. Other threads here as well (like that light rider Pike one) also suggests that even 75 psi would be too high exactly as you say. I reckon lower pressure and possibly a faster rebound will set me right.

Might be able to get to Swinley a week earlier, so can post my thoughts after that if anyone's interested.