[shock]

those of you familiar with our (therapy components) philosophy on floating brakes know that, whenever possible, I try to insure a neutral force on the suspension from the brake rod. You also know that some of are designs are not quite neutral due to space restrictions.

But I always say to be open minded about things (especially if you haven't ridden them). Well Fabien Barel, Kona team rider, wanted to try something different with a floater, so we made this for him.

This is the setup Fabien and Tracy are currently racing.

Enjoy, discuss, disparage.

 

[kidwoo]

That goes against the parallelogram I've heard a few people talk about with floaters. Maybe that one is more X treme.

 

[Westy]

Maybe he likes the way URT's brake?

 

[CBJ]

It looks a little bit like the placement on my 222 which reminds me I wish I smart and knew what moving the floter to some of the lower holes on the frame would do - anybody?

 

[Kornphlake]

Isn't that roughly the same as if it were parallel, all that's being done here is the links are crossed, as long as the distance from the axle to the tie rod mount is about the same as the distance from the main pivot to the opposite tie rod mount and the tie rod is as long as the theoretical chainstay the effect is the same rather the links are crossed or not.

 

[BMXman]

hmm..well what happens when the wheels get out of true?...looks kind of tight in there....D

 

[zedro]

well, that goes completly against and opposite of the wheel path philosophy i've been using.

Is this just a random geometry you used, or do you actually have a theory behind it? because using my model, it seems traction would be comprimised (or conversely, neutrality).

 

[paranoid56]

can somebody tell me why we have floating brakes? it just does not make sence.
Thanks (yea, noob here )
Shane

 

[cali4niabiker]

Gee, it looks like you got a new tire there... maybe the old 2.7" didn't fit with the new floater in there. :nuts:

 

[RhinofromWA]

Isn't that roughly the same as if it were parallel, all that's being done here is the links are crossed, as long as the distance from the axle to the tie rod mount is about the same as the distance from the main pivot to the opposite tie rod mount and the tie rod is as long as the theoretical chainstay the effect is the same rather the links are crossed or not.

Staring at it earlier I was trying to come to that conclusion.....

But I do beleive that will draw the capiler arm forward more than a static swingarm mounted brake system whhile teh suspension is cycling up. Rotating the wheel/brake caliper slightly forward as the bike impacts something is the ONLY thing I could come up with as being beneficial...if that can be beneficial at all.

As the swing arm rises the control arm will be pulled forward and down. The chainstay distance does not change but the control arm caliper mount is going away from the frame mount....so it gets pulled towards the frame mount.

My head hurts.

 

[OGRipper]

Does the rod telescope at all during suspension travel? Some kind of built in extender to keep it neutral despite the placement?

Otherwise I agree with Zedro, seems contrary to the usual theories for floaters.

And I also agree with Rhino, my head hurts too.

So what does Fabian think? Have you been able to ride it yet?

 

[Kornphlake]

So I made a simple model in CAD and observed how the above system would move. I was a little off, the caliper bracket will not remain parallel to the mounting point.

It almost looks like in the bottom of the travel the harder you squeeze the brake, the more the suspension would want to compress although this condition may never acutally occur depending on the distances between the pivots. If the rider experiences the placebo effect and believes his suspension is working better under braking, then I guess the floating caliper would work as well as any other floating caliper.

 

[RhinofromWA]

So I made a simple model in CAD and observed how the above system would move. I was a little off, the caliper bracket will not remain parallel to the mounting point.

It almost looks like in the bottom of the travel the harder you squeeze the brake, the more the suspension would want to compress although this condition may never acutally occur depending on the distances between the pivots. If the rider experiences the placebo effect and believes his suspension is working better under braking, then I guess the floating caliper would work as well as any other floating caliper.

Curious as the suspension compresses how does the oreintation of the caliper change? Does it rotate forward or Backwards?

 

[buildyourown]

From what I can see, I think that setup would exagerate brake jack, not help eliminate it. Bu hey, maybe Fabian likes the stinkbug.

 

[neversummersnow]

My initial thoughts were maybe it helps the bike squat when brake is applied. Some people prefer this.

 

[Cave Dweller]

I think it helps stiffen the flexy kona's rear end

 

[prerogative]

The brakes line came to long stock, so he wanted to use up some without cutting it . . .

It would pull the brake forward on the chainstay rather than push it back - I think it'll compress the rear on hard braking.

 

[eastcoastzigzag]

but how is the efficency of the flux capaitor concerning the path of the rear wheel? sorry i had too..............

 

[shock]

theory of floating brakes.

That goes against the parallelogram I've heard a few people talk about with floaters. Maybe that one is more X treme.

The floater we actually make (sell) for the Stab Primo is a little more conventional.......

btw kidwoo, did you ever get your version done for your DHR?

 

[shock]

It looks a little bit like the placement on my 222 which reminds me I wish I smart and knew what moving the floter to some of the lower holes on the frame would do - anybody?

While the forward rod placement is similar to the Orange, the overall geometry and force directions are quite different.

BTW, by moving which hole the rod is connected to, you can tune the response of the floater, i.e. from neutral to compressing the rear under braking. Try them and let me know if you can actually feel a difference.

 

[shock]

Isn't that roughly the same as if it were parallel, all that's being done here is the links are crossed, as long as the distance from the axle to the tie rod mount is about the same as the distance from the main pivot to the opposite tie rod mount and the tie rod is as long as the theoretical chainstay the effect is the same rather the links are crossed or not.

Completely different than if it was parrallel. Think about the direction the force is being fed into the frame.

 

[evilbob]

From what I can see, I think that setup would exagerate brake jack, not help eliminate it. Bu hey, maybe Fabian likes the stinkbug.

No, that configuration will not stinkbug the bike.

 

[evilbob]

My initial thoughts were maybe it helps the bike squat when brake is applied. Some people prefer this.

A winner!

The best part about floating breaks is the force is directed into the frame rather than the swingarm. Keep in mind that the further away (above or below) from the swingarm pivot the load is applied into the frame will create greater leverage to extend or compress the rear of the frame. In the crossing configuration you will get compression of the suspension and in the parallel configuration the force applied will try to extend the suspension. How much is dependent on several things. The objective is to keep the rear suspension in a position wear it can remain active while breaking not allow breaking forces to keep the suspension completely topped out or driven into a to firm place in spring load. Some parallel designs tend to make the rear of the bike ride alittle high, the breaking action may be smooth but on steep terrain can be a little unnerving. To much leverage in the crossing configuration can cause the rear to compress the suspension to much, and keep it that way which would feel like having way too much rebound dialed in across chop. The trick is getting the right configuration and leverage to match the frame configuration.

 

[dw]

To back up what has been said previously, this design will compress the rear suspension onder braking more so than the stock setup. The standard therapy design will compress the suspension less under braking than the stock design.

dw

 

[kidwoo]

theory of floating brakes.



The floater we actually make (sell) for the Stab Primo is a little more conventional.......

btw kidwoo, did you ever get your version done for your DHR?

Actually, I put on a propedal fox in lieu of the romic and the bike no longer suffered from the problem anymore, at least not nearly as much. I'm thinking it may have something to do with different platform thresholds between the two designs. Hitting the brakes and unloading the rear a bit was maybe taking off just enough of my weight that the platform damper started to have an effect. Just a guess since I was using the same weight spring with both shocks. Anyway, it felt much better in situations when I was dragging the brakes a bit over the super rough stuff. Thanks for all your help though.

 

[zedro]

To back up what has been said previously, this design will compress the rear suspension onder braking more so than the stock setup. The standard therapy design will compress the suspension less under braking than the stock design.

dw

i'm still thinking traction under bumps will be comprimised....

 

[kidwoo]

i'm still thinking traction under bumps will be comprimised....

I'd be more concerned about traction OVER bumps. Never tried riding under them though........you may be on to something.

 

[zedro]

I'd be more concerned about traction OVER bumps. Never tried riding under them though........you may be on to something.

what, you dont have a molecular phase inverter?

 

[punkassean]

I talked to Dr.Dew at the '05 launch about the Stab and the addition of the floater. He did confirm that Fabien really likes the way the bike "squats and loads" because it "rockets" out of corners. Fabien believes he is faster this way, he might just be right.

 

[wirly]

He did confirm that Fabien really likes the way the bike "squats and loads" because it "rockets" out of corners. Fabien believes he is faster this wayQUOTE]

I'm with Fabien I always feel much faster after I "squat a load."

 

[shock]

well, that goes completly against and opposite of the wheel path philosophy i've been using.

Is this just a random geometry you used, or do you actually have a theory behind it? because using my model, it seems traction would be comprimised (or conversely, neutrality).

You (and evilbob and others) are correct. This geometry will have the tendency to compress the rear suspension in proportion to the rear brake force. Compared to our standard floater geometry for this bike (pictured elsewhere in this thread), this will result in a less active suspension while braking, and less traction between the tire and ground. BUT, it is still better than no floater.

This geometry was driven entirely by Fabien's desire to experiment. His hypothosis was that a) his bike has more travel than it needs for the majority of WC courses, resulting in 2) a high center of gravity and thus c) less effective cornering. He also wanted 4) more "negative travel" in the rear suspension, which he felt would give him e) more traction in braking bumps!!

So, if that's not confusing enough, he's changing his spring and damper settings to work together with the floater to achieve this goal.

When he asked me what I thought, I reiterated my stance that a more neutral geometry would benefit the majority of riders more.

When he asked if I was worried about supplying him with something that we didn't sell, and that went against our company "line", I said hell no, and I'm happy to supply the technology to test further concepts, and to keep my mind open to those concepts.

Does it work? Of course it works, better than no floater. But it does require recalibrating the suspension to take maximize it's potential. Is it what we should offer for this bike? Again, for most riders/conditions, I don't think so, but maybe as an option (as if we need more options).

So there you have it.

 

[shock]

can somebody tell me why we have floating brakes? it just does not make sence.
Thanks (yea, noob here )
Shane

paranoid56, there are probably hundreds of threads on this subject, but, in general, a floating brake will remove the braking force from the suspension, which will remove any tendency to pack up or jack up (depending on suspension design).

This results in a much more active suspension while braking, without the hopping, skipping and otherwise feeling that the suspension isn't working as well while braking. You'll have better control, and increased braking from the rear, due to the tire tracking the ground better.

Of course, not all floaters are created equal, so your mileage may vary.

 

[Sideways]

Unless you're trying to build anarcho-bicycle-choppers that don't ride as you'd expect or want them to...then that's just stupid.

Does this Fabian dude just drag his brakes all the way down the hill?
This is the most ass backwards way of getting a bike to have less squish that I've ever seen.

Makes me want to ride a '93 Trek 9000.

 

[kidwoo]

Unless you're trying to build anarcho-bicycle-choppers that don't ride as you'd expect or want them to...then that's just stupid.

Does this Fabian dude just drag his brakes all the way down the hill?
This is the most ass backwards way of getting a bike to have less squish that I've ever seen.

Makes me want to ride a '93 Trek 9000.

You ever seen Fabien Barel ride?

They guy knows a thing or two about getting his bike to go fast.

 

[thaflyinfatman]

Unless you're trying to build anarcho-bicycle-choppers that don't ride as you'd expect or want them to...then that's just stupid.

Does this Fabian dude just drag his brakes all the way down the hill?
This is the most ass backwards way of getting a bike to have less squish that I've ever seen.

Makes me want to ride a '93 Trek 9000.

Yeah, Fabien Barel drags his brakes the whole way down the hill.... and still manages to podium at WC's.

 

[vitox]

This geometry was driven entirely by Fabien's desire to experiment. His hypothosis was that a) his bike has more travel than it needs for the majority of WC courses, resulting in 2) a high center of gravity and thus c) less effective cornering. He also wanted 4) more "negative travel" in the rear suspension, which he felt would give him e) more traction in braking bumps!!

not meaning to pick on your work because it seems you got the guy just what he wanted, but the logic doesnt quite work for me, i mean if he wanted less travel why not just, emm, less travel? if he wanted more sag then why not less spring? too high bb, why not a shorter stroke shock with 25lbs less spring on it?. that coupled with some orthopedic crowns for his 888 and a neutral floater would on paper at least address all 5 points you outlined.

 

[neversummersnow]

I might be the only one that understands why Fabien did this. I understand it and agree with it in this application.

 

[vitox]

I might be the only one that understands why Fabien did this. I understand it and agree with it in this application.

great, care to explain?

 

[zedro]

I might be the only one that understands why Fabien did this. I understand it and agree with it in this application.

understanding and agreeing are two different things....

 

[kidwoo]

I guess I can understand why someone would want this. Think about a floater in general and what it's supposed to do.......let your suspension work when braking wants to do the opposite. Although it does happen, braking with only one brake at a time is more uncommon than using both. So assuming a bike starting to drag (as a whole unit) from braking wants to throw the rider foward, this in turn causes an unweighting effect on the rear end....also a rising effect with the suspension/rear end of the bike. So why not try to make the thing squat a little so that this rise is counteracted a bit? The effect would be that what weight you do have on the bike has a greater effect on the rear suspension when you do hit bumps while using your brake.

And don't anybody start this crap about not using your brakes over bumps. It happens.......with everyone.