| Author | Message | ||
     Arthurc |
I see the 2007 models have a progressive rate fork spring that claims to "provide wider range of smooth progressive control of front suspension over long fork travel". The HDU Technical Forum for the 2007 Model Year mentions it does retrofit and I'm considering doing it. Anyone done this yet? Care to share your experience if so? I'm also assuming their comment that it "requires the new front and rear 2007 suspension specifications" means they have different recommendations to the suspension settings and that both front and rear need to be readjusted. Guess I'll need to get a copy of the 2007 manual to determine what the new recommendations are (though I'm assuming the instructions for the fork spring kit would include this). | ||
| Birdmanrh |
Kit? I bet you get two springs.  It is not a chrome Harley part after all. (I doubt it will be hard to get the new specs) Oh, BTW take a look. http://www.sonicsprings.com/catalog/straight_vs_prog_tech_article.php (Message edited by BirdmanRH on September 08, 2006) | ||
| Lovehamr |
I doubt we have to worry abut this to much; "One of the problems is that bikes, street bikes anyway, just don’t have enough travel to take advantage of progressive rates."  | ||
| Arthurc |
Thanks for the reference to that website Birdmanrh. I'm a bit surprised that Buell has moved to these on the Uly as standard atire for 2007 if there deemed so bad. Of course, one has to take a spring manufacturer's article with a bit of suspicion. I'm supecting they only sell the straight variety (though I didn't look to see). At some point someone will upgrade or someone will have ridden both for some extended time to be able to comment on the new fork springs. For now, I'll just enjoy it as is and see what transpires over the winter months. /a | ||
| Rhinowerx |
I have the springs on order - expect they'll be in stock later this month. Still trying to decide if I'm going to fit them myself or not (don't have the spring compressor). Was thinking maybe a 'tech day' would be cool - we could change springs, do TPS adjust, oil change, adjust primary chain... Anybody? | ||
| Birdmanrh |
Ya think they sell straight rate springs? LOL I think the ULY needed a detuned suspension for most and I am pretty sure that a progressive front spring will give you exactly that. It will allow for a lot more leeway in setup and you will not hear a lot of people complaining about a "swimming" front end. Me, I like the flexibility of the setup the way it is. I would consider progressive rate springs a "detune." But, I stated a long time ago that it was needed for the sales of the bike. | ||
| Stevenknapp |
I've pulled/swapped fork springs without any special tools on conventional forks. I'd assume the upside down ones are the same. The challenge is not cross threading the fork caps while pushing down preloading the springs. Since the Uly has the preload adjusters (my Triumph did not) you might need a big deep well socket to clear those. Also being a total tool-freak at times, I got a Facom ratchet. It has a disc on the top of the ratchet head which spins. So you can push on it with your hand while turning the socket....I doubt you *need* this. http://www.mytoolstore.com/sk/sk03048.html | ||
| Jmhinkle |
I have to disagree on Progressive springs being a "detune." You ever own a KLR650? Talk about a major tune up! The straight rate springs are so soft that you can easily bottom them out without much effort at all. Of course I don't feel all the cracks in the road either. And talk about brake dive, I guess that is why I didn't notice on the Uly. With Progressive srings you get a more controlled and expected rate of motion. With straight rate they are generally too hard or soft. With progressive you get a little more compliance for day to day use, but at the same time once you absorb the soft part quickly under hard braking you are into the stiffer area and get less dive from them. You basically get both a softer and stiffer spring in one and they do work. Joel | ||
| Birdmanrh |
Nope, I have never had a KLR650. It is a cool bike! I just can't seem to find progressive springs on anything but cruisers. (and cars) I don't have an issue with brake dive or bottoming out either? Where do you have your settings? | ||
| Paochow |
I had the same issue with my wife's old KLR-250, the stock springs would bottom under even moderate braking. Progressive rate springs were a great improvement. | ||
| Jmhinkle |
Birdman, I was referring to brake dive and bottoming out on the KLR. They are a popular upgrade for many dualsports. I have seen people mention brake dive on the Uly. I have it, but it isn't as bad as many bikes I have been on so it doesn't bother me. I believe that was the reasoning for going to the progressive springs for '07 though. I have my suspension set on the high end of the below 200 weight and it works really well for me there. I weigh 185 and with my gear on and stuff in bags, I should probably move up one setting, but I think it is too stiff for daily commuting there. I also live on a dirt road that is rather rough and the stiffer suspension makes it a chore to control the bike so I keep is softer. Joel | ||
| Ulendo |
man, on the stuff I do, I'd just about kill for progressive rate springs. not often, but I've hit a couple of whoop-dee-doos REAL hard, and progressives would sure soften up the landings!! birdmanrh - leaf springs are, in essence, all progressive rate...the more you compress them, the more leaves become involved, and the stiffer the overall rate. if you look at the competition 4x4's using 3/4 liptic setups, they take it one step further by having a progressive 1/4 spring for extension, and a conventional semi eliptic for compression. here's a shot of the prototype suspension under my old rover, to give you some idea..  as the axle drops, the upper short spring extends, an the farther it extends, the SOFTER the spring rate, as there are fewer leaves involved. under compression, the upper spring pack sits flat under the frame, and the lower pack does all the work - the more it compresses, the more leaves ( and deflection) and the higher the spring rate. extreme example in the real world, what it means is, if you leave the ground ( or go over a whoop dee do) the first part of the suspension is very soft, to soak up the landing with no jarring. as you come further onto the springs, it gets stiffer, and stiffer, preventing bottoming out the suspension. normal driving is exactly that: you only notice progressive suspension at the further reaches of travel. (sorry for the non-bike example - I just happen to have this photo handy, and its a REALLY good example of a progressive setup !) | ||
| Brad1445 |
I was so excited I asked my dealer for them the week the 2007 models were introduced. WOO HOO! | ||
| Birdmanrh |
Yea, so you are not convincing me that progressive will dive less.... If you soak something up, you have to use travel.....To not use as much travel you have to increase rate, or feel it faster. | ||
| Uwgriz |
"To not use as much travel you have to increase rate" Exactly. The progressive rate springs are just that, progressive rate. It allows you to have multiple rates for different situations. An excessively high spring rate is uncomfortable to ride around on and your tires would lose contact with the road much easier so you need a more reasonable (read softer) spring rate most of the time. Under hard braking, you don't want a bunch of dive (i.e. fork compression or travel), so you want a stiffer spring (increased rate). So how do you get the best of both worlds? With a progressive rate spring. Under most conditions, the stiffer part of the spring does little, the softer part does most of the job. Under hard braking, the softer part of the spring becomes near fully compressed and you get into the stiffer part of the spring which will limit the travel, hence less dive. Imagine how much brake dive you'd get with an infinitely stiff spring, such as a block of steel, in your forks. None, right? (Stoppies don't count.) A progressive spring gets you more of that effect without compromising ride quality and handling. | ||
| Jmhinkle |
Birdman, The amount of the softer section is designed that when it is used up and you are in the stiffer section, the relative spring compression actually less than what a straight rate spring is. Does that makes sense? | ||
| Birdmanrh |
No, it doesn't. I completely understand how a suspension works, you guys are the ones that are not "getting" it. If you have a softer section it is a certain part of the travel. It must be used up before you get to the stiffer part and then stop the brake dive. Therefore the distance is either the same or more. (yes, you can make it less) The only way to counter the distance is to create a huge spring rate at the bottom end of the spring. (Much like a solid piece of steel.) What you end up with by using a progressive rate spring it less distance of usable travel and a bottom end of spring range that is completely useless. What you gain is an easier to understand spring for setup because you have a much larger range in which you can be wrong in setup without a drastic problem. Buell needed to do this, in fact they should probably "upgrade" the suspension with less adjustments as well. Step back and think for a second and explain if this is the best type of spring, why would Buell go with a linear rate spring to start? Price is not an obstacle as they cost practically the same.....they can't teach everyone, but they can detune the bike to make it easier to sell... | ||
| Birdmanrh |
BTW, This is viewing this vehicle as a primary street vehicle. There are benefits to the progressive spring in dirt use as described above by Ulendo. I however view my legs and arms as additional suspension in those instances as I don't view this bike as a dirt bike. (Totally different deal!) | ||
| Ulendo |
Birdmanrh - try this - the spring rate controls the ride quality. Your DAMPING rate controls the rate of change. if you want a compliant suspension, with less dive, use progressive springs, and dial UP the damping. the net result is that on slower 'bumps', the oil control passages have enough flow capacity, and the suspension will move relatively freely. the faster/harder you hit something, the more resistance/ damping comes into effect. progressive springs with active damping give an incredibly controlled ride. BTW, that rover is street legal, w/ very little body roll, or pogoing, but has almost 5 feet of rear wheel travel (30"+ at the springs). | ||
| Blake |
Birdman, What if the initial "softer" spring rate is the same as that for the old uniform spring but it progressively increases with compression? Or maybe for the first two inches of travel it is less stiff, then from two inches compression onwards it progressively exceeds the old spring rate? Say it takes 80 LBs to compress the new progressive rate spring through its initial one inch of compression, but it takes a total of 600 LBs to compress it fully through five inches. Is that more or less stiff than a linear (constant rate) spring with a rate of 100 LBs per inch? I also think some are neglecting or diminishing the role of damping in this situation. Damping plays a huge role in how smooth or rough a ride is. Suspension science is simple on the surface (spring and damper), yet extremely complex in the state of the art details. Sure is interesting to discuss. | ||
| Birdmanrh |
Blake, If you set the spring up that way all you do in take away travel, because you will never be able to use the bottom third of suspension. It is simple, the progressive spring "de-tunes" or "pre-tunes" the bike. At the end of the day you will add the progressive rate spring, max your compression (damping) and minimize the rebound (damping). (Maybe the other way around, my head hurts) Thus making the bike easier for people that do not know how to setup a suspension. Brake dive is eliminated by setting a proper compression. Comfort is set by balancing the rebound. All of this is based upon starting with the proper preload. None of this will be an issue unless you are really aggressive in the corners, that is where the front will really show issues. Glad I got a 2006.  | ||
| Dennis_c |
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| Ulendo |
all I can say on part of that is our views on bikes apparently differ on a serious note - WHY does the brake dive bother you so much? given the braking power available in the front disk, moving the weight onto the front wheel actually allows more traction & more braking...so long as you dont pull a stoppie, and lose control. ( NB: I ride supermoto style - if you're expecting touring bike dynamics...) | ||
| Birdmanrh |
I have no issue with brake dive, I don't have it. I would say our views on suspension period differs. I deal with race vehicles on a weekly basis. Progressive has a place, but it is always as a compromise. (lowered street cars for instance) | ||
| Birdmanrh |
BTW, here is a suspension for ya. Notice two separate linear rate springs on one shock. Not a progressive spring. http://www.desertrides.com/features/vehicles/gordonTT/imagepages/DSC02342.php What you showed earlier with leaf springs and regular springs works the same way, but it is not progressive. It is a spring/helper spring setup. Additionally notice the angle of the shock placement (The same as a rear shock on a bike) That gives a slight progressive rate to a linear spring. Don't think too hard our you might start to realize that the front forks are not actually straight down..... Don't worry about it, you can do whatever you want and then deal with what ya got. BTW, anybody have the new suspension setup specs?? | ||
| Blake |
"If you set the spring up that way all you do in take away travel, because you will never be able to use the bottom third of suspension." I disagree. I think you are making a big mistake ignoring the damping factor. And I think you are also mistakenly assuming that the suspension never ever bottoms out. I might agree somewhat that for the most part a progressive rate spring is compensating for lack of a good/fully adjustable damping system. But why then do HRC and other racing teams employ variable rate rear suspensions, which yield much the same effect as a variable rate spring? I think there are advantages to the progressive rate spring that you may be missing. | ||
| Birdmanrh |
We are talking about the front fork springs, NOT the rear. The rear is progressive simply by its mounting! You do understand how a lever works...right? I did not say that you never bottom the suspension out, I was answering the question of "what if." If you take my comments out of context they of course will not hold the same meaning. (What you quoted was an answer to the previous post, not a general statement about progressive rate springs MMMkkkay?) There is nothing wrong with a progressive rate front spring, I think overall it was the right move for Buell sales wise. It is however not an "upgrade" to performance on the street. Offroad I am not going to argue. Not sure what spring really would be high performance for a 500lb dirt bike. Of course it is not marketed or sold as a dirt bike anyway. | ||
| Birdmanrh |
Anybody get the 2007 manual? | ||
| Brad1445 |
Anyone who says they have no front end dive on a 2006 model rides like a little girl. | ||
| Ulendo |
<quote>I deal with race vehicles on a weekly basis<endquote> umm, yah - and your point with that is?  by the same token as your statements: race cars have nothing to do with bike suspensions. Also, if you had anything to do with driving, or wrenching on race cars, rather than seeing them at photo shoots, you'd know that most of them use progressive coil overs.... ( Nice photo link on your ADV rider profile, BTW - I notice you stir the pot over there as much a here. (either that, or there's one heck of a coincidence in user names)) |
