Nesty

Just for the sake of argument, does the consumer really ride liter-class bikes to their potential, and then purchase based upon their own perspective?

Or does a mfr. build bikes to win races, then get them reviewed in Sport Rider, CW, Motorcyclist, and give a whole litany of the technical reasons why their bikes are winning races and the annual liter bike shootouts in the cycle magazines?

Like LDH said, if there was a huge advantage, they'd be doing it and then marketing the living daylights out of it. Look at Yamaha (cross plane crank), Honda (mass centralization), etc.

BMW would have been perfect: new entry into market, new BMW I-4, ...new front suspension...

bloaker

The consumer buys their perception of cool. Not their abilities or the bikes abilities.

Plenty of bikes are built and not raced. The F2, F3 and F4s were streetbikes for honda that were built for the street and converted into race bikes. They had tremendous success doing that. The 600rr was the first 'race first' 600 honda made. Just an example where the race track was not first and foremost. I am sure there are examples to the contrary as well. But my answer to the racing is 'not always' - Why did the 600rr come about? Cause people wanted the 'race bike' even though in most applicatons, the street first bike is much better. people wanted it because it is 'cool' - Better on the race track does not equal better on the street.


I would not argue whether or not the advantages on any of them are "HUGE"
Actually... 'in a blind taste test' scenario, I am not even sure if the 'better' forks or more expensive forks would win.

My impression has always been top dollar forks are very narrow in scope. Then only work well when pushed to the limit they were tuned for. A race specific set up will not have the adjustability in it to back off to a street setting on a high dollar system. They are designed for fine tuning for a specific set up. Not general setups.

Basically... a top set of track forks are a detriment to you on the streets for everyday use.

Pvster

bloaker is quite right.... most people sadly do not have the capability to think independently. marketing and hype is HUGE (take a look at what H.D. did. they sell bikes that still use technology from the 50's). if people buy into the marketing and hype, people are generally hooked from that point on.

UJM

Funny you say that -

I rode some BMW we took on trade, sport touring machine I think it was, and it had that funky swingarm type front end -

Worse handling motorcycle I ever rode, the steering had nearly zero feedback, I hated it.

Pathetic for any motorcycle to be as numb as that one was.

HondaJim

Personally, I've read all the arguments here and I think anyone who believes MotoGP doesn't do it for any other reason than it's not the best is full of it.

If they put it on a bike and it won every squid in American would want it. It's not a budget breaking deal for them to build it, period.

The original thread was why inverted. If we've moved on to what is best, right now there isn't anything better at an unrestricted (from a front end standpoint) setup than inverted forks. I'm not saying there won't ever be anything better, but I don't believe it exists yet.

cmurphy84

This thread is entertaining and informative.

I have nothing useful to add so I'd just like you to know I like tater tots.

bloaker

I disagree. Go up to the average squid and they have never heard fo MotoGP.

UJM

Ummmmmmmmmmm......................

Bryce919er

Did not read all of this. Inverteds are stiffer, thats why. Ancient samuri says look to the long legs of the dirt bike & see the truth.

mcromo44

Actually, in a real world sense in terms of production bikes for regular riders on street tires, there's more advantage from the typically superior internals fitted into the USD forks of the day, as compared to the typical super economy based and less sophisticated internals inside of most conventionals.

Bryce919er

As long as we are comparing good USD units to poor conventionals we might as well take it one step farther & say none of it really matters anyway for 80% of the population, 15% think it matters but really doesn't, & the last 5% actually ride well enough to be able to tell.

lmtdgov

I always assumed USD forks were better bc of stiffness and also that the oil is then pulled towards the seals and keeps them nice and lubed.

Unfortunately much of rob's info was went right over my head, but I've always thought it's crazy how motorcycles with standard forks don't have some sort of arching brace (like mtn bike forks) to help give the axle some help in the stiffness department.

Any companies tried this design on a motorcycle?
Cannondale | Headshok Philosophy

Snikwad

thats a lot of reading, cliff notes, you all are gay.
my USD forks and radial brakes are fukin ballin, that is all.

/ thread.

Lord Duckhunter

For some reason I spat coffee on that one Snik!


I really wish I could find a way to properly adapt a set of the latest FGRT Ohlins forks to my old trusty 1000RR just for testing purposes. The new FGRT's have fluted tubes that are designed to the increase "tuned "rigidity (not as stiff on the sides etc) and they feel incredible on the Duc's, but that is not an apple to apple's comparison and I know there is some unwanted flex in the older style Ohlins forks I use currently and they are supposed to be the stiffest design. You only notice it during extremely high speed transitions like the back kink at Barber where you literally have to push & pull on the handlebars like mad just to get the bike to steer at speed. It would be really interesting to see how much torsional stress is put on those forks under a load like that because I know it is way more than one would expect. The inertia of the bike at that speed along with the grip from the tires has that bikes wound up like a 2 dollar watch through that section of track & when one of them lets go it is always spectacular

Relic11

Exactly the same... only different Bimota

bloaker

He goes and calls us gay....... and he is my roommate... brave!

Snikwad

hahahhahaha.

touring919

It appears we have moved on from is USD better. Maybe we are now convinced it is better or maybe we have short attentions span. But I'm going to stick with the what is thee best movement of this thread....

I have never seen a head shock on a motorcycle. Your very limited in travel. Comopair any head shock cannondale to a comprable mtb with convenstional front suspension.
I have wondered why no one has used the lefty premis though, in a fork, which uses bearings instead of bushings. Doesn't even have to be round. Could be eliptical, with the damping system as its on unit incases by the tubes (elipticcal tubes). I think motocyc (the company that went for eletric racing after it had to give up dreams of racing 990 motoGP) has something like that but I don't remember the specifics.
Fork bracess are used on motorcycle set ups. Only seen them on convensional forks though. Since the bracee would move with the wheel (like your fender). On a USD fork the brace would have to be so high it wouldnt' do much more than the lower clamp alreay does.

elf did use a hossak front end. They had essencilly unlimited funding. They didn't do all that well. Had there high points but nothing to prove hossak was the way to go.

the k1200R cup I think proved what happens if the hossak sytle suspension is used in racing. lots of guys fall down. Low sided by loosing the front. Could be lack of feel, could have been from the sudden geometry change as the front did squat as it leaned over (can't preload it with the brakes), could have been from lack of tire development for that type of setup, could have been lack of rider skill to adapt to the necissary riding style. Lots of what ifs, which is why the thread is still going, but nothing has been seen yet that really justifies anything other than a telescopic fork as the best.

touring919

Which moves me to my next point. Since someone brought up mtb. Ever notice how much more sophicticateed a mtb rear suspension is than a motorcycle. What the hell. I can't belive that the swing arm is still used. A multi link setup can be used on the rear of the bike much more easily than thinking of a way to "fix" the fork. Tuneable anti squat, Keep chain tension more consistant, wheel base changes would be minimized, and more easily tuned.

I don't think I have ever seen a modern bike with something other than a basic swing arm. Kinda sad.

nd4spdbh

thats a whole nother topic haha... i think it has to do with the fact that motorcycles have much more power than the human rider and that there are much greater forces at play... although if you can do a single sided swing arm im sure you could mimic a mtn bike rear on a bike pretty easily. There are multi link designs... just look at any race dirbike suspension... but not like that of a mtn bike.

But then again that is a whole nother topic

REDROKR

fork it

lmtdgov

I referenced the cannondale suspension designs due to their needle roller bearings on a semi squared tube. If this was applied to the standard USD or conventional forks along with a solid axle I would think you would have one extremely stiff front suspension.

Funny though, Cannondale says their system allows for smoother moving suspension, but I always thought their headshocks and leftys were kind of sticky feeling.

bloaker

Working in a cannondale shop for years....

If properly set up, it works like a dream. That said, I have only owned one cannondale and hated it. The geometry did not agree with me. Due to a deal I made with our rep, I had to give up my two bikes for 3 months and ride the C-dale excusively. I tried to like it.... but wrong geometry is just wrong geometry.

Back to the headshock & lefty... The lefty was/is a fantastic fork on the trail. It blows on parking lot test rides because you are too focus at looking at the fork (or lack there of) than actually riding into things worth while

There are several lefty's out there and one of them is dog poop. I hated it. One of the others is stil to this day my favorite to ride. (working at the dealership, I rode a lot of them, only owned one...)

As for the rear suspension.... Specialized has a 'smart shock' - do some reasearch, it is amazing. GT has the 'idrive' - great theory, poor execution. Many brands use a single pivot design as well. All bicycle suspension (on good bikes) are designed with the rider 'bobbing' up and down while pedalling. This is very different from the motrocycle premise.

touring919

The bobing up and down is different yes. But using chain tention/drive forces to fight unwanted suspension movement is same same. Just different inputs and objectives. We currently use swing arm angle on motorcycles of around 12 degrees to combat squat at the rear. With a multi link setup the same effect could be had without having to have a very narrow usable range of swingarm angle. And I'll mension again the benifits the lower degree of chain slack variation. I'm sure it would be easy to make it strong enough to handle motorized power. Weight, complexity. Could be a problem. But hey, if people power can handle the extra weight and complexity I would think and engine could.

As for the forks. My lefty fork is very smooth and responsive. Very little sticktion. My only dislike for cannondale is that they are too unique. Makes finding parts while broken down more dificult. And removal of the front wheel is a PAIN. On top of the wheel retainging bolt wearing out. Which mine has. But with that design it would be very easy to make a rectangle instead of a suare. So logitudinal stiffness could be higher for braking and latteral could be less stiff for flex while leaned over. not sure how one would get the bearings to tollerate the flex. Rollers instead of needles is a good start.

bloaker

Bushing and bearing wear out on milti link suspension. They are service intensive.
To me, there is very little to gain for added maint.

mcromo44

Links allow modified suspension travel curves that can be even further tuned, as compared to simple swingarms. Lots of proddie bikes have them. I'd say that steering head bearings are a scarier bearing issue to contend with than the those in the links. I think they are more of a service issue on MTBs and dirt bikes than they are on road bikes.

Danke

Why invert the forks? More overlap between the slider and stanchion so more support = stiffer or less slop. You have to take this in context and take a look at what forks were like when the inverted forks became wide spread. In one short word they were awful.

Telescopic forks are an evolved item, and the evolution has not stopped. There was a flood of USD forks and as a part of that some people (dirt bikers) were not happy with them. That jarred the folks who made RSD forks out of their rut and they came up with better forks that did not have the extra weight and dead feeling that USDs had. A guy on a dirt bike loads his forks up very differently than the typical road racer and too stiff was an issue for them. They want the forks to still suck up bumps when they’re sideways up a berm not flex like a noodle, still be very light, and of course affordable.

Motorcycle forks that led to the headshock would most likely be the White Power single sided version that used linear roller bearings. That's mid 80s vintage. Don't forget Cannondale had a motorcycle road racer on staff as one of their designers at the time this stuff was cropping up.

And for current MTB rear suspension, once again it's evolving at a massive pace. It does have to be very different from motorcycle suspension due to the inputs you put into it. Real multi link ones are light years ahead of the single pivot stuff. If you want an inexpensive bike that goes boing and you ride in a very limited parameter you may be able to find a single pivot design that works well for you. Otherwise there is no reason to worry about a suspension system that runs multiple pivots in the manner of a pantograph.

Motorcycle rear suspension uses the same four moving bars around a virtual point that the bicycles do. The bicycles do have more going on because of the limited HP a human can put down and the desire to filter out the pedal bob and ride a magic carpet.

touring919

Motorcycle rear suspension uses the same four moving bars around a virtual point that the bicycles do. The bicycles do have more going on because of the limited HP a human can put down and the desire to filter out the pedal bob and ride a magic carpet.

No they don't. Motorcycles use a single pivot. The shock actuates through muli links on a lot of bikes to give it a non linear curve. But the arm contecting the wheel to the frame is a single arm with a single pivot. Its like a fancy formula car's damper bell crank design but connected to the rear suspension of a VW bug.
The rear of a mtb uses many different designs. One of them is a double A arm style deal like the front of a BMW K bike. Giant's use these alot. not sure about other companies. And from there they use mulitple ways to connect the shock to those suspension arms. Some directly, others with fancy links.

Danke

I hate to rain on your parade but it is a four bar linkage. I have mapped out both motorcycle and bicycle suspension in kinematic software and they are the same.

The four bars on a motorcycle are, the shock, the swingarm, the rocker, and the link. Now if you are riding an old bike with cantilever dual shocks then you're excused from the four bar club.

I had the good fortune to attend a multi-day seminar put on by Tony Foale, and then after use the software at work to map out our bikes. A couple of his rants were on how marketing departments at motorcyle companies seize on an idea and distort how it works to sell product. Yamaha and Honda were some of the folks noted.

Some bike companies are just as bad or worse for dressing up something as unique when it's the same as every other bike on the block.

As an aside if Tony Foale ever does pop up in your area to put on a class it is worth it's weight in gold to attend.

mcromo44

Um, no .......

Suspension travel curves are not a simple function of a swing arm pivoting on a single pin for link style setups. The links alter the rates in spring and dampening forces throughout the travel as function of the link layout. You are thinking of rear axle centreline travel arc but that is only a portion of the overall equation.

sike

Way to go Nesty, now even the Canadian's are fighting....

mcromo44

how was your weekend ride ?
did your boots stay dry OK ?
still lots of ice and snow in the shaded areas on our side streets

sike

It was a beautiful ride to the north, the food at the cafe was AWESOME, then on the way back the skies opened up and the boots got a bit wet, real wet. Luckily, I have USD forks and they work much better in the rain than those old forks ever could have.....

nd4spdbh

^ HAHAHHAHAHAH!

mcromo44

As an element of proper decorum, one must also maintain a sense of humour, n'est-ce pas ?

And you have !

touring919

I agree with you. Rear axle centerline travel is what I was refering too. It is a simple constant radius arc from a single pivot regaurdless of how the shock is attached. The fancy links for shock attachment just change the spring rate and damping at the wheel with respect to that arc (travel).

touring919

What bicycles? there are many that have a motorcycle style rear suspension. And many that don't.

touring919

By the way. The "cantilever" style dual shock system you wer tallking about is a 4 bar mechanism. The frame (1), the swing arm (2), and the shock, which is a slider link and conts as (3) and (4). It has 3 pined locations and one sliding location. W

With this setup there is a single fixed instand center, which is the swing arm bolt. Same as any other motorcycle rear suspension as on a 919 or a CBR.

The double A arm though is a 4 bar mechanism but its instant center is not constant and is not not located at any of its pined locations. The shock is not a bar in this setup, its mearly a damper and spring.

Now I'm off to figure out something I just thought of that Danke may be able to use against me. Crap.

Danke

If it doesn't have four independent moving bars it's not a four bar.

Look at a pantograph, it has four moving bars. You use it to copy pictures with. If you change the length of the bars you can enlarge or shrink the picture. A four bar suspension does the same thing but instead of a picture it's feeing the X inches of wheel travel into the Y inches of shock travel.

Now if you took that pantograph and locked one arm so that you only had three arms what would the picture you generated look like?

Now you can take a 2:1 leverage system like the old dual shocks bolted to the swingarm or the Yamaha Cantilever monoshock and induce a rising or falling rate based on where you stick the pivots but it just won't have the same function of a rocker system.

You can thank dirt bikes for the current rocker system. When their real wheel travel started ramping up the 2:1 ratio was overwhelmed the rocker gave more mechanical advantage. The road racing guys didn't want to be left behind at that point and the rocker does give some packaging advantages when you're trying to jam everything into a tiny little race bike.

For performance bicycles the four bar linkage is the most prevalent system. There are some of the old leverage system ones around from folks like Santa Cruz and Orange but the meat of things are in the multiple pivot camp.

Lord Duckhunter

unsubscribing...