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SSINGA said:
Wow, that does look pretty dramatic. I wonder what it actually looks like with a rider and some damping. I haven't seen anyone complaining about the braking on a HL or DHR (or a TNT RFX for that matter). It'd be interesting to see/do a back to back comparison with a floater to see what difference it may make. Tscheezy will probably make one out of whalebone and moose hide and be the first to test it out. :thumbsup:
 

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wilks said:
kona are basically saying unless you have the DOPE system their bikes are $hit, that aint smart marketing......
I think that they already know that people know there bikes are $hit...errrrr...I mean...have that little braking issue. I think it's pretty ballsy of them to admit that weakness and I give them credit for actually doing something to fix it. It'd be interesting to see how their sales go...whether more people opt for the upgrade, or they lose sales because people can't afford the upgrade. Not that Kona would actually share that info with the public. I guess if Kona drops the DOPE system in the next model year we'll know that the market didn't bite.

As it could apply to Turner Bicycles (the floater), I wonder if it'd even make a difference in sales. Probably not. It's not like people aren't buying Turners because they have brake jack. Nor are they buying them because the braking is the best on the market, it's the overall package. JMO.
 

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www.derbyrims.com
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You don't need it. But that bike has a lot of range for brake tuning, from monopivot if you could set the seattube 4-bar link clamp down at the main pivot, aiming further forward past FSR (about as compressive as this system could tune), to near neutral squat 4-bar Five Spot when IC is aimed at the fork, even Lawwill and Ellsworth rising rear suspension brake geometry boosting brake dive the further the IC is outside the wheelbase. The differences are very noticeable tuning 4-bar brakes on the same bike.
 

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Natl. Champ DH Poser/Hack
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well im impressed. very impressed even. but before i sell all my turners and bid ya farewell for the kona forum, allow me to play devils advocate for a moment, i mean, for a bit.

by the looks of that vid dew got super clever and mounted a 22mm c/s mount hayes caliper as the non dope stopper on the same rotor as the standard IS caliper used for the dope. not a bad way to simplify the demo and show folks the same rig was used in both tests. but this is where my question stems from.

i do know that a caliper mounted from a clockwise point at roughly 270 deg (hayes) will react diferently with the rotation of a rotor to a caliper mounted at roughly 45 deg (IS). you can try this with a cd and yer fingers. simply hold the cd in the center, pinch it in both or any variety of places with yer other hand, then turn it as a brake rotor would turn. its super important to try and hold the center of yer "rotor" on a even plain. now see how each position reacts? the hayes caliper really trys to lift the axel point up and forward just like dews vid while the IS calipers reaction is minimal at best.

so my question is, does konas test rig show 2 real world results in a controlled enviornment or 2 very different parameters? it seems like we have a dog and a cat here but im also not the brake engineer either.

also, please understand im not sayin dew and the kona guys are tryin to dupe us with dope. if im right, and i think i am, the demo could be a honest mistake, slightly exagerated test results and hopeful marketing.
 

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What they fail to mention, is that Barel runs his floater such that the suspension actualy compresses MORE under breaking than with the regular IS mount. Rumour has it it's to lower the bike under breaking such that the bike is more manouvrable for cornering or something...
 

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Lay off the Levers
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It's an interesting test. I can't believe after all the handwringing, debate, graphs, and theorizing, nobody thought of simply removing the damper to demonstrate braking effects. Kewl!

Some imortant caveats here:
-This still does not account for magnitude of the effect. We can see it move a damperless shaft but that's quite different than real world forces with a properly sprung and functioning shock. To say any amount would degrade the ride is IMO wrong.

-A small amount of compression could be considered a good thing... if the fork is going to dive under braking (what fork doesn't?) then having the back end lower some will help equalize the pitch forward and lend better balance. The front end sure as heck isn't going to be neutral. This is why the Rail and DHR aren't usually run with floaters.

-cc points out the calipers are in different locations. I think it would be better to compare two identical setups w&w/o the floater.

I really dig this test because you can see the potenial of brake effect and even pedal bob in various gear combinations. But one really has to keep in mind without measuring magnitudes, you have no idea if what is visually obvious, is physically substantial when you bolt a real shock and have a real rider hitting real rocks. The spring offers a great deal of resistance and under load the damper offers a huge amount of resistance. Combined, the two cannot be ignored when considering braking forces.

Lastly Turners ain't Konas... there are a lot of differences in design that are not at all obvious to a "gee-they-look-alike" type comparison. I'm not bagging and I'm not going to say it will be vastly different but two similar bikes can have different character, just like two dfferent bikes can have similar character: consider Tscheezy's review as well as comments from others that the SP Yetti 575 to be very like the HL Spot.(obviously not in every way)

It's a kewl demo... but don't make any sweeping judgements yet.
I think I'll slot a paintstick and swap out the dampers on my HL-Spot and TNT-RFX just to see for myself. It won't show what a floater can do but it will be fun to experiment anyway.

Hey is it just me or did the host have a scary ax-murderer kinda presentation-style?:D (yeah, like *I* should talk?:rolleyes: )
 

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I don't do PC
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cactuscorn said:
well im impressed. very impressed even. but before i sell all my turners and bid ya farewell for the kona forum, allow me to play devils advocate for a moment, i mean, for a bit.

by the looks of that vid dew got super clever and mounted a 22mm c/s mount hayes caliper as the non dope stopper on the same rotor as the standard IS caliper used for the dope. not a bad way to simplify the demo and show folks the same rig was used in both tests. but this is where my question stems from.

i do know that a caliper mounted from a clockwise point at roughly 270 deg (hayes) will react diferently with the rotation of a rotor to a caliper mounted at roughly 45 deg (IS). you can try this with a cd and yer fingers. simply hold the cd in the center, pinch it in both or any variety of places with yer other hand, then turn it as a brake rotor would turn. its super important to try and hold the center of yer "rotor" on a even plain. now see how each position reacts? the hayes caliper really trys to lift the axel point up and forward just like dews vid while the IS calipers reaction is minimal at best.

so my question is, does konas test rig show 2 real world results in a controlled enviornment or 2 very different parameters? it seems like we have a dog and a cat here but im also not the brake engineer either.

also, please understand im not sayin dew and the kona guys are tryin to dupe us with dope. if im right, and i think i am, the demo could be a honest mistake, slightly exagerated test results and hopeful marketing.
Good points CC, but I bet the caliper was mounted on the chainstay cause they just couldn't mount it in a standard IS fashion due to the floating brake. I'm not sure mounting the caliper at the IS location OR on the chainstay would make any diff though cause both are still the chainstay right? I bet for certain riding cond's the floating brake would definitely make a diff on my TNT RFX, like at Keystone or the shuttle ride we do here.
 

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carpe mañana
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Bikezilla said:
It's an interesting test. I can't believe after all the handwringing, debate, graphs, and theorizing, nobody thought of simply removing the damper to demonstrate braking effects. Kewl!
Yeah, which of you Homers have both stay sets? Lets see a DOPE style demo!

On a side note, it appears that the rear suspension is squatting under braking, not jacking.

_MK
 

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Rolling
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I like how he said, they removed the spring to "overemphasize the effect"

If you have a hardtail, mount it on a bike stand and do the same thing. I think it will try to rotate the whole bike in the same direction (conservation of angular momentum) They mounted the bike rigidly so you can't see that effect. Sure, the rear wheel and triangle have less mass so the effect would be larger with no shock, but most of that is normally offset by the spring force and compression damping in the shock, the rest is transferred to the frame.

I guess I would like to see the effect with the shock in a normal setup. In fact, one should be able to put their bike on a stand, put a zip tie on the shock, measure the defection doing this and from this, calculate the force.
 

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lidarman said:
but most of that is normally offset by the spring force and compression damping in the shock, the rest is transferred to the frame.
Rich, Yeah that's what I was saying.... your point about the hardtail and whole rotational moment is something I didn't think of. Good call.

Way back when I got my DHX I was testing the force required to compress the mounted springless shock at various propedal settings by putting weights on the seat. It was quite interesting to see how a little more PP ramped up the resistance. I also did the same with the Romic. Geek..geek...geek...

MK I have both a TNT and a HL Turner. It's easy enough to slot a paintstick so the linkage bolt can slide up and down the proper stroke length uninhibited. It'll demonstrate the phenonomon but not the magnitude or what difference it'll make on a real, sprung, working damper, under load.
I don't have a floater though...at least not outside the bathroom.

Methinks if floating brakes made that big a deal difference, a lot of ppl would already be running aftermarket kits...hell they've been out forever.
 

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Rolling
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Bikezilla said:
Rich, Yeah that's what I was saying.... but your point about the hardtail and whole rotational moment is something I didn't think of. Good call.
I got the typical zealous drive and didn't read all the posts before adding my two-cents. :mad:

One thing is for sure, the law of conservation of angular momentum is a fundamental law of physics.
 

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carpe mañana
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lidarman said:
I guess I would like to see the effect with the shock in a normal setup. In fact, one should be able to put their bike on a stand, put a zip tie on the shock, measure the defection doing this and from this, calculate the force.
I think an even more interesting test would be to observe the suspension behavior under braking when it is slightly compressed. It could be that the floater is causing some jacking, or extension, which I would not say is desirable. It may give you more traction, but it may throw you over the bars on steep descents. I'll stick to brake squat.

_MK
 
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