GuzziMoto

Sorry, I was asking you a serious question but I realized afterwards that it was a waste of time and tried to delete it before it was too late. Obviously I did not succeed. Sorry. But the short answer to your question(?) is back in post #28 where you claimed to have gotten a 31% reduction in your "sag delta", "The sag delta dropped by a great whallopping 31%" while saying that you only increased your spring rate 11lbs (about 2% of the original spring rate, 532lb). You followed that with with a bunch of fancy words that had little to do with the topic (mostly designed to insult the people who did not agree with you) and then a "Helpful reminder" which presumably was intended to explain the large change in your "sag delta" from a small change in spring rate. It went as follows... (from post #28) "HELPFUL REMINDER: When changing rate on the shock spring, there's a ~1:2 multiplier at work WRT sag delta change vs. spring rate change, due to the 1:2 swingarm leverage (shock travel to wheel spindle travel)." This statement, "there's a ~1:2 multiplier at work WRT sag delta change vs. spring rate change, due to the 1:2 swingarm leverage"is what I was asking about. You pointed out that your"sag delta" was 100% affected by/representative of spring rate. It is actually affected by other things as well but spring rate is the biggest influence on the difference between your free sag and your race sag (you call that number your "sag delta"). I am sorry I brought it up. I apologize to the rest of the board.

To each their own but my wife and I have no issues with just a little fly screen up to 90 - 100 mph constant and occasional spells above that. Of course we would never go that fast on the street

Let me try some more. First, it is a 1:2 ratio of shock travel to wheel travel. That is different then a 2:1 ratio. In fact it is the opposite of a 2:1 ratio. Think of a 1:2 ratio as 1" of shock travel equals 2" of wheel travel. So if 400lbs of force (weight) will compress the spring 1" then the wheel will move 2". So it takes 400lbs to compress the shock 1" but only 200lbs will move the rear wheel 1" (and 400lb would move the rear 2") So a 400lb rear spring with a 1:2 ratio would feel like a 200lb spring since 200lb of weight would move the rear suspension 1". If you had a straight 1:1 ratio then with a 400lb spring it would take 400lb of weight to move the rear wheel 1" and 200lb would only move the wheel 1/2". That would feel like you had a 400lb spring at the back. But with a 1:2 leverage ratio that same 400lb spring would only feel like a 200lb spring since 200lb would move the rear wheel that same 1" that the 400lb spring with a straight 1:1 ratio would require 400lb of weight to move. Hope this helps.

No, it is a 1:2 shock to wheel ratio, not a 1:2 ratio. It works like a lever. A given force will move the rear suspension twice as far as the shock moves but it is only doing half the work. In this case the work is compressing the rear shock. And a given change in shock length ( that is all preload is really going, is setting the length of the shock under the weight of the bike)will have double the change at the rear wheel as it moves 2" for every 1" of movement at the shock.

Yes, a 400lb spring takes 400 lbs to compress it 1". But if you apply the force at the rear wheel 200lbs would only compress the spring 1/2", but as the rear wheel moves twice as far as the shock it would appear that the rate of the rear spring is only half what it really is. That is why a change in rate at the spring will only have half the effect at the wheel as it did at the shock. That is part of the reason rear springs are sold with much higher rates then fork springs and the increments of change between the different rates is much larger. It takes a larger rate change at the rear to accomplish a given change in how the suspension works then it does at the front, where springs are typically sold in steps of 12.7 lbs/inch. Of course since you have two springs holding up the front of the bike a 12.7lb change equates to 25.4lbs at the wheel (not taking the rake of the forks into it). Edit: Whoops, sorry. I had a decimal one place off. Fork springs are actually sold in steps of 2.799lbs/inch. I am not sure what you mean by "effective spring rate" but if you mean the rate that it will feel like then no, a 400lb spring with a 1:2 leverage ratio between the shock and the wheel will feel like a 200lb spring.

Measuring the stock shock is the best way to get an accurate spring rate from it. You can have pro's do it with real measuring equipment or you can do it yourself. All you need to do is measure the force it takes to compress the spring a measured distance. The standard for rear springs (in the US) is how many lbs to compress the spring 1", but that is a high number and going for 1/2" or even 1/4" would likely do just fine although it would double or quadruple your error factor.

I don't see how telling others how I set up my wifes V11 is helpful to others. Telling them how to set their bike up correctly could be useful, but that is not my job. As mentioned there is plenty of info already posted on that very subject there for the reading. My concern and the reason for correcting the errors in Wackers post is that many here and others browsing through may not know that what he said was not 100% fact and if no one questions it they may believe it to be so. I do not worry about every little inaccuracy, but when there is more wrong then right I feel compelled to speak up. If that is not a good thing to you or anyone else here then I encourage you to skip my posts. But if you feel how my wifes V11 is setup will help you, well I am not crazy enough to post info on the internet about my wifes weight but I will give some info about the components. It has a Penske shock built and valved for her weight and style. After putting it on all I had to do is take a couple clicks out of the compression. Where it ended up matters little as the valving is specific to her shock. The spring rate would relate to her weight so you will have to guess. The preload and sag is pretty much standard fair. I didn't have to adjust it after Penske built it. They do good work. The fork I have the stock springs in and sag is okay (woops, I may have said too much), but I did modify the valving so that the fork actually had compression dampening. As delivered there was only rebound dampening and a slightly adjustable hydraulic bump stop. That required blocking off oil passages in the cartridge to force oil to go through the piston instead of around it. I have mentioned this before but either no one else has forks like this or no one else has thought it is a problem. The fork mods made a world of improvement turning the harsh feeling front end into a much smoother but sharper feeling ride as they no longer bottomed over every decent size bump and reacted much quicker to front end inputs. No sign of the Twitchy Red Frame Demon either (no steering damper either, that was also a huge improvement but as it was bad it is not a fair comparison).

No ego involved here, at least on my part. I just don't want to see somebody read something here and assume that because no one pointed out how wrong it is that it must be right and then base decisions they make on bad info. I see your response to having it pointed out that you are wrong hasn't changed. The quality of your insults has little to do with whether you are right or wrong. But I imagine it makes you feel better. You speak of providing "value" to this discussion, but what sort of "value" are you adding, when you post info that ranges from slightly wrong to completely wrong. As I said, not everything you post is wrong but sometimes you get out on the thin ice of your own knowledge and don't seem to know it. If you have some sort of argument to support your claims then by all means bring them out for all to see. As for your insults to me I don't care. Your words are feeble and weak, old man. They mean nothing. Post up something to show how superior your knowledge of motorcycle suspension to mine and put me in my place. Otherwise, it's just noise.

dlaing, you are correct in that you can figure out the OEM spring rate (at least pretty dang close) if you have accurate numbers on the sag with the old spring and accurate numbers with the new spring as well as an accurate rate for the new spring. But I believe you are incorrect that the ratio of rear shock travel to rear wheel travel does not enter into it. It does, but opposite the way Hatchet Wacker says it does. The 1:2 ratio means that a 50 lb increase in spring rate at the shock would have a 25 lb net effect at the rear wheel since the rear wheel only moves half as far relative to the rest of the bike for a given amount of shock movement. This means that while an increase of 50 lbs in spring rate at the shock would only result in an extra 25 lbs being required to compress the rear suspension 1". This fact coupled with the measurements Hatchet Wacker provides leads me to think that his numbers don't add up. And rather then try to figure out what the actual rate change is it would be easier to measure a stock spring myself. Just a matter of time to get to it. Edit... After thinking about it I think you are correct that the ratio doesn't enter into it as all measurements are taken at the rear wheel and are comparable as a percent. The ratio is only going to determine the wheel travel for a given shock travel and thus only effects results at the wheel relative to changes at the shock as hard numbers not percents. The percents will be the same. Sorry dlaing. I think you're right.

I am not so sure there is "always hope". For example, I used to "hope"that you would stop with all the name calling and insults and actually limit the discussion to facts, but I can't see that ever happening. What would you have to say? Edit.. Sorry that was mean. I apologize. Hatchet Wacker does provide good info in many cases. He just doesn't seem to know the difference between what he knows and what he thinks he knows.

Wow, Hatchet Wacker,that was almost coherent and correct. But, not quite. Some of it could be attributed to opinion and different ways of seeing things (ie, is the glass half full or half empty, whether you have straight rate or progressive springs). But normal preload does not effect spring rate unless you have a set of aftermarket progressive springs, so unless you have so much preload that there is no sag adding or subtracting preload does not make the ride stiffer or softer unless you consider that with out enough preload the suspension will bottom and the ride will seem stiff or harsh. With straight rate/stock springs preload effects ride height, with virtually no effect on spring rate unless you are way off one way or the other. Now, you and a few others do have progressive springs in the front. And while you may be perfectly happy with them, the fact the changing preload/ride height alters the base spring rate is one of the reasons I don't use progressive springs. But to each their own. HW, you almost got the bit about the ratio of spring rate to travel correct, you even seemed like you were gonna say it and then you didn't. You say there is about a "1:2 swingarm leverage (shock travel to wheel spindle travel)" ratio for the shock travel vs. rear wheel travel (based on yours and others measurements of the rear suspension, I doubt it is a constant rate and likely changes through the stroke of the rear wheel), meaning that a 500 lb spring will allow the rear suspension to(added for clarity) compress one inch under 250 lbs of weight. This is opposite to what you imply/say with regard to your "measly" 11 lb rate increase being larger then it seems. It is in fact smaller then it seems. Meaning that a 50 lb change in the spring rate at the shock is only good for a 25 lb effective rate at the wheel. But up front the ratio is 2:1 wheel travel to spring rate, because of the fact that there are two springs, the opposite of the rear. A small change up front makes a larger difference since it is doubled. And finally, while it is true that the amount of sag with a rider on board is not as useful a piece of info without knowing the amount of free sag (no rider on board) to say that the difference between the two is the only number you need to know, well that may be something that comes down to opinion. I can see how if all you wanted to know is whether your spring rate is correct or not then maybe you could make an argument that that was all you need. And if you spring was truly a straight rate spring then you might even be correct. But since springs aren't all straight rate and when there is a linkage or angled shock involved the effective rate of the spring (the effect it has on the movement of the rear wheel) is no longer straight rate, that statement is a bit misleading. If you are sincerely trying to set up your suspension then you need to know free sag and race sag (sag with rider on board). The difference between the two is not as important as what the two are. If you set your race sag and your free sag is too high or too low (or none at all) then your spring rate is off. It is that simple. Getting the first two right is what it is about, not just getting the difference between the two to a given value. But that one as I said could be down to opinion and you are entitled to your own. Funny the two links you posted did not support your opinion on that matter. Well, one thing I can agree with you own is that anyone interested in learning about suspension setup should go out there and research the subject. There is much info out there and much of it is good. But as this thread illustrates you can't believe everything you read on the internet. Let the insults begin.

It's not my bike, and you can certainly paint your bike any color you want, but since you asked for opinions here's mine. Even Ducatis look better in yellow. And there is something "wrong" about painting a Guzzi in Ducati red. And the original maroon was a beautiful color. Not what I would have done.

Yes, the Cyclone and Blast screens are different. But they both have the hump in the center and will fit with the stock gauge cluster on a V11. I just wanted to point out that the Lightning screen had the hump offset to one side and it does not fit the stock V11 gauge cluster. The gauge cluster on a Lightning is offset to match the screen. It is a cool look and I like it, but making it work on a V11 (offsetting the gauges to match) is a bit more work. The center hump fits the bulge in the stock set up with out modification. What I really want is to go with is the dual headlight and fly screen setup off one of the newer Lightnings on my Daytona/cafe project. But that is pie in the sky.

Only thing that I can add is that the 99 and up Lightning used a different fly screen with an offset hump. The M2 Cyclone or Blast screen is what you want if you are using the stock V11 gauge cluster. The early Lightnings ('98 and before) had the hump offset to one side and the later ones (99 and later) had the hump offset to the other side.

We get about 40-42 mpg (US gallon) with a 2001 V11 running a PCIII. Your map has a large effect, as does your riding style and even the local fuel content.

The M2 Cyclones and Blasts had fly screens with the hump in the middle. The tube frame X-1 Lightnings had the hump offset to the side and don't fit the same way. Not sure of the year ranges, but if you go with 2000 you should be fine.

Nice. Those will look good in black. Who did you buy them from?

You could try switching the injectors and seeing if the issue moves with them. Reading colors is not as useful as it used to be due to completely different fuels we use nowadays. But it is odd that you have such differences between the two sides. It could be from one side being too rich, but it also could be burning oil on one side or a burnt valve (oil burning is more likely in my experience, but it could be rich). As I recall Guzzi's are odd in that they do not use valve guide seals. Instead they depend on the valve guide and stem to seal and keep oil out of the ports. Not a good idea when you make your valve guides from hard cheese and your valves from soft cheese. As mentioned, a leak down test would be useful. And swapping the injectors would be the first step towards isolating a sticking injector. If none of this pans out then I would take a look at your valves. It is not hard to pull your heads on a push rod motor like your Guzzi. Best of luck.

Christ, you guys keep your beer so cold, how could it go "sour"?

Better late then never. I will say that Todd did a great job with my ECU, modding it and coming up with a Power Commander/AutoTune module set up that made a night and day difference in how my Griso runs. Thanks Todd. What do you know about 4V Daytonas?

It means the BMW GS series is the ugly bike standard, the yard stick by which all other bikes are measured.... "bike "X" is 70% as ugly as a GS". There is no bike that reaches 100% on the scale. Even other SUV bikes are in the 80-90% range. Yes, I am a fan of Buells, as well as Guzzi's and most other motorcycles that are outside the box so to speak. I even like some BMWs. I have owned Buells before and likely will again. In fact, part of me wishes I kept my tube frame X-1 that I sold to buy my Griso. That bike was good looking and an absolute blast to ride. I wish Guzzi would make something that much fun to ride. The Sportster based engine was not the horsepower king, but it had more torque then any other streetbike I've owned. And it delivered it in a raw unpolished way that gave you an old school thrill and inspired you to do things the law says you shouldn't.

Good price in my opinion. You would have to look at the bike and confirm its shape. 18,000 miles on a Guzzi is nothing, as long as it has been maintained reasonably. Look thru the threads on model differences and things to watch for.

I do not have current numbers but based on numbers from a few years ago Guzzi was selling 6,000 bikes a year globally (less then 1,000 sold in the US) and Buell was up to 13,000 a year globally range (about 1/2 of those were sold in the US) in 2008. I believe Buell sold 136,923 bikes total since inception, with the vast majority of those in the last ten years. BMW sold about 13,000 bikes in the US in 2006. All these numbers are scrounged up off the internet and none should be considered absolute fact.

Sales figures indicate that they were selling way more Buells then they sell Guzzi's. And in this country I think they weren't that far off of what BMW's numbers were, if not better then, although with the massive profit margin on the BMW's they certainly made more money selling BMW's. The fact that Buell is gone as a maker of street bikes is not cause for celebration but concern. Guzzi makes far less bikes (and money) then Buell. It is not that hard to see Guzzi going the same way. And the Buells were much more of a "function dictates form" motorcycle then BMW, everything on a Buell was designed with function in mind first. Form clearly came second, whether it was the underslung exhaust (that has now been copied by many) or the sideways mounted radiators with those ugly scoops to push air through them. And if you bought a BMW GS and are not blind then I'm pretty sure by law you are not allowed to call any other motorcycles "ugly".

I don't care if there is life on other planets, we're just looking for ATM's.