Hey everyone! I just set up my suspension today in accordance with the info I've gained in the VFR forums. My concern is this: In order to get the front forks within tolerance I had to practically bottom out the adjustments as hard as they would go. I'm 1/4 turn from bottoming out the front forks. The rear suspension fared somewhat better in order to stay within specs. it's set at the middle of it's range of motion. My bike is an 06 with a little over 5ks on the meter. I'm 6 foot and weigh around 210lbls. I set the suspension up with just my weight no added luggage. Is this about right for the stock suspension? I know the stock suspension isn't the best however I don't have $1500 bucks for an upgrade so the stock will have to do. Any advice is greatly appreciated!
You don't need that much to get proper spring rates for your bike. Fork springs are under $100 and I can get you a spring for the rear shock for $85 including installation. That's probably a good place to start, I think you'll notice a huge difference with the correct springs on both ends.
That's about right. Unfortunately Japanese bikes are built for well, Japanese people. Thanks for reminding me to go crank up my front end. The rear is stiff as it can go, I was meaning to do the front the correct way (with a friend to push down and measure) but I don't think it needs to be that complicated, just crank her down. I'm about the same size as you.
I took the bike out today for a little 60 mile trip just to check out the suspension adjustments. I purposely chose some old two lane back roads that are full of patches and uneven roads. I live in the Arkansas Delta, rice and soybean country so all the back roads are farm roads and some are really rough. The suspension is now a lot tighter than before, therefore I was thinking that the ride may be exceptionally harsh but to my surprise it wasn't. In fact the ride wasn't as harsh as before! Guess with the soft set up I had way to much rebound going on. The bike seems to be more responsive in handling, turning in and out. I did crank the rear shock up one more setting before I took off in hopes of getting a little better response in the front end and it seemed to work well. I'm really pleased with how the suspension tune up turned out. Of course I'm now at about the limits of the stock suspension but in hopes it will hold out for a long while. I'm trying to put back as much change as I can for my upcoming trip in May to Deal's Gap, so I can't afford any major suspension updates as of now so I'll stay stock until funds become available.
As for the front forks I did the suspension on mine I weigh 275 lbs I bought Racetech springs(you can custom order the springs from them according to your weight) and went with 10 weight oil in the forks and added an extra 2 shims in the back shock and my 5th Gen tears up the road! I actually kick up the ass of my buddy when we are out ripping around and he owns a 2008 CBR 1000! He's also a track guy and he's good but the VFR stay with im.
If you're carrying a bunch of crap with you on your trip don't forget to crank up the rear shock for the added weight AND increase your tire pressure to something close to the maximum recommended so you still have rubber left when you get there. I think 42psi is pretty common on most tires for the max load, put it there cold and when you get there drop it back to about 36psi without luggage. The best suspension in the world is nothing if you can't make it stick and the best rubber is nothing if you can't put it on the ground.
I'm about 200lbs in full regalia w/helmet, and ride fast and quite hard, but smooth. For my '94 I'm running the forks at max preload (OE springs), max damping, with 20wt oil (firmer damping), set about 1/2" higher level for reduced bottoming (it never bottoms out). I could probably use about 7-10% firmer springs, and may just go with about a 3/4" PVC spacer instead of new springs to save $$. The OE springs aren't quite ideal, but close enough provided a smooth riding style. The ride is comfortable but firm enough and adequate response/feedback - a decent overall compromise for streetwork. I also run the fork tubes raised in the clamps 12mm (lowers the front end of the bike) to sharpen steering a bit and create a more forward weight bias (I am a "front end rider") for a more planted front end feel (stock size tires). This accomplishes the same as raising the rear ride height, except for a slight reduction in ground clearance; however as I'm short I prefer the slightly lower saddle height as compared to raising the rear end. For street use it makes no real difference; frankly if ground clearance/ride height are a big concern on the street...take it to the track... *Reduced ride height also slightly reduces Cg and enhances a stable feel, albeit at slight loss of "quick flick" feeling due to screwing with the Polar Moment/Roll Center etc. - but honestly, it's a VFR, on the street - don't worry about it! Raising the rear is better for track use but not always an option; lowering the front is generally easier and adequate for street use. Leave this concept to the truly competitive racers - I'm just acknowledging it for the techno weenies to avoid an unnecessarily complicated discussion of things that have no real bearing on the issue at hand... And yes, there is also the inevitable impact on rear Squat and resulting Understeer/Oversteer tendency when altering ride height/chassis attitude, but again not really relevant for most people, especially for street riding For the rear I'm at about 80% of max preload, with rebound damping about 2 clicks out from max (winter/commuting). For summer/faster riding I increase rear preload about 2 full turns to about 90% of max, with damping 1 click out from max (rear damping got suddenly harsh at the max setting). Again, about 7-10% firmer spring might be optimal, but it's good enough for free! Perhaps not ideal, but close enough with smooth form for fast riding, and excellent well-damped suppleness on rougher pavement. A very good overall compromise for the VFR's mission and all-around do-anything capabilities. "Good enough"is as close to perfect as one can get for zero budget...:redface: Ideally, I would prefer about 15% increased low-speed compression damping on both ends; Rear high-speed compression damping "as is"; low-speed rebound damping similarly increased about 10% F&R; Rear high-speed rebound damping increased overall about 10% with greater range of adjustability, and overall spring rates increased about 7-10% F&R. It ain't bad - ya just gotta be smooth and remember that the VFR will happily do things the RR bikes will want to buck you off for! For your own personal "best" settings, you'll want to know your true weight with complete gear ready-to-roll to determine optimum spring rates, and start by setting "Static Sag" - Google for the correct procedure or contact any decent suspension specialist (GP Suspension, Race Tech, etc.) for a "How To" - that's the only truly accurate way to determine exactly what you need to do. Season to taste... (damping adjustments for your style & level). FWIW, I run my tires generally about 33-36psi Rear, and 30-33psi Front (depending on the tires and temps) - saving the "Max" psi's for just that - Max loads (2-up with luggage and full fuel).
Thanx Rat for the info!! Hell man, you done forgot more about suspension set up than I ever thot of knowing. I'm just a take it easy type of rider. I get somewhat aggressive but nothing like you do, I just don't have the experience although I've been riding for many years off and on (I'm 60) I don't have the riding talents that you speak of, nor do I have near the knowledge of motorcycle physics. I did set the static sag and rider stag according to info I've gained on this web, got it out of suspension threads. The bike is now set up for my riding weight and it felt great. You mentioned for a cheap fix I could shim up the front springs and add some heavier fork oil. If you don't mind could you elaborate on the procedure or if you would rather not in this thread just drop me an email. I'm really green in this suspension stuff and I have to read the stuff over and over to get my brain around it! I've read some of your other threads and your general knowledge of the VFR just astounds me. I'd like to keep in contact with you for general questions, I may even become a pain in the "ol butt" but I gotta learn some how.
Thanx for that info Hotbrakes!! I knew to do that but had not thot about it due to this suspension stuff. Hope I remember to do that before the trip. I'm putting new rubber on the VFR come spring and I dam sure don't want to ruin new tires on the trip!! I'm leaning heavy towards the Continentals.
Thanks for the kind words - I must admit that while I have a gleaned a few things over the years about motorcycles in general, there are a few guys here on VFRW that have much more VFR-specific knowledge than me. If not already, you'll soon become familiar with who they are (I decline to name names, at the risk of forgetting someone or several...). For better or worse, I was born with a technical mind and an innate ability to understand vehicle dynamics, aerodynamics and most mechanical/technical processes, which also translates into actually making a vehicle do what I intend, as well as the ability to analyze and understand why it may not be doing so, and just what to fix or adjust about the machine or my inputs to achieve the desired performance. Re: Static Sag I consider this a Very Scientific and Absolutely Precise method to obtain a decent "ball park"... ;-p That is, it's all very scientific and precise and all, which I thrive on, but when the flesh meets the machine, it still all comes down to your own particular style, ability and personal preference. In other words - "Properly" set Static Sag, even by experts, is still just a starting point to get close to your own ideal setup. Don't be afraid to firm things up or even soften from that point if it feels better to you and the riding that you are doing. The "Best/Ideal" setup for any rider is whatever combination of all possible permutations that allows that rider to achieve his best performance, or desired goal. For instance - I freely state that I realize that my own particular style is a preference for a responsive and communicative front end, with rear suspension performance being much less crucial FOR ME. I have the most confidence, and therefore go fastest, with the front end dialed in. It's not that I can't feel what the rear end is doing, but my riding style allows me to adjust for it and not really care! (and I'm not exactly chasing Championship points, so a few 10th's per lap off my best possible pace of my favorite local mountain backroads really isn't crucial...). Some guys need the rear end set up exactly to their liking, and can't really tell what the front end is doing. *(I also seem to have a knack for sensitivity to tactile feedback - an ability to sense very small incremental differences and other dynamic inputs). So, even the most professionally set up suspension is still just a good jumping off point (hopefully not literally!). Any 2 MotoGP or WSBK guys may have lap times within a few hundredths of each other, with possibly wildly varying suspension preferences and setups (and countless other variables). It all comes down to whatever works best FOR YOU - or to drag out a phrase from the swinging 70's - "If it feels good, DO IT!". Or to put it another way - You don't have to know wine, to know what wine you like! Re: "Cost Effective" (read: "Poor Man's") fork tweaks: If the fork spring are fairly close to what you need (want...), and you don't "see the value" (can't afford) of installing new springs, a properly sized spacer can effectively increase basic spring Preload to bring things closer to your ideal. From a purist point-of-view this is a compromise and perhaps somewhat less than ideal, but for a buck or two at Ace Hardware it's a cheap fix and good enough for streetwork. - Basically, just support the front of the bike in a manner to bring the front wheel completely off the ground, with no load on the fork tubes for minimal fork/spring preload - Use a auto jack under the exhaust collector (my method, quick and simple) or a come-along ratcheting cable pull hanging from a garage rafter with a sling around the chassis' headstock in front of the fuel tank. - Back off the preload adjusters all the way to remove as much possible spring preload as possible (there will still be some spring tension). - Loosen the handlebar clip-ons and slowly remove the fork top with the correct socket or box wrench, while holding a shop rag over the top cap with your free hand to stop it from being flung off by the spring underneath. - Pull up the spring enough to measure it's OD (outside diameter), and the stanchion tube's ID (inside diameter). - Take these measurements (or alternatively, the entire fork top cap) to your local home/plumbing supplies emporium to find some sort of PVC tubing that best fits with minimal slop (or just scrounge around your garage or nearest unattended commercial building site...). Depending on how far off you feel your springs are for you, typically about 1/2" - 1" should be sufficient. If you need more than a 1" spacer you really probably actually do need to WD40 your creaky wallet and spring for new springs (pun intended ;-) ). - Reassemble in reverse of how things came apart, with your fancy new high-tech spacer at the top. Keep the preload adjusters backed off to zero upon reassembly and reassess Static Sag again, working up preload as necessary. It's all really pretty simple, if a bit tedious and maybe scary depending on your own mechanical aptitude/adventurousness. ** Feel free to Google the procedure for more detail and possibly photos, but it's really quite straightforward. Now, the downside/compromise with using a preload spacer is that the actual spring rate hasn't changed, and obviously isn't really optimal for your weight. *As anal as I am about all things technical, I temper my "enthusiasm" with real-world common sense and experience. Although this issue/compromise is really not truly important for streetwork and other than truly competitive racers (as in 2-digit number plates). The issue is that ideally, any suspension spring should be operating in roughly the middle of it's entire range: Too firm a spring uses only a small portion of it's total stroke/range with resulting too-firm ride quality and inability to compress adequately to absorb larger road irregularities - the ride is bouncy, skittery when cornering, and the bike/car cannot efficiently transmit power to the ground. Too soft results in either bottoming on the bumpers with no ability to absorb any shock at all, or possibly gross amounts of preload that can result in coil binding, or at least insufficient total available stroke length to absorb larger inputs. With all of this in mind, I encourage each rider to make the decision that best fits his own preferences, needs, financial wherewithal, and willingness to compromise... Re: Heavier fork oil: Heavier oil slows movement through the valve's orifices/shim stack, thereby slowing the fork's movement through the stroke. Less responsive/firmer damping. Fork oil is cheaper than fancy Gold Valves etc, and needs to be changed periodically anyway as the viscosity breaks down and it gets dirty (just like motor oil), so it's a good time to switch to something heavier and just consider the expense as "routine maintenance". This is easily changed and the ideal time is when you are already popping the top caps off to say, install preload spacers... - With the front end raised (wheel off the ground), before removing the top caps, remove the small drain bolt (10mm?) at the bottom of each fork slider (drain into a pan...). - Leave a pan under each drain hole. - Remove both fork springs and use the front wheel to pump the fork up and down a few times through it's stroke. - Replace the drain bolts (don't forget the tiny washers) when the oil seems to have stopped draining. - Refill with good quality 20wt oil measured by either volume or distance from the top of the stanchion tube (each bike is different). *This is really not an exact science - "Absolute" draining and exactly precise refill volume are not critical (unless your bike is currently wearing a 2-digit-or-less number plate...). Close enough is good enough, but better to err on the slightly too much side when refilling. I'm sure anyone can find really good How-To's of these procedures on the interweb with little effort. These are just to show how simple this stuff actually is - no need to make it more complicated than it needs to be. ps - Just post any and all technical questions up on the forum - someone should respond. If you still have questions feel free to PM me. Rat
