Basically stock streetbike. Been playing with suspension and it's improving. Bike pitched bad (front rose) when changing direction now the front and rear roll more together w/less pitch. I changed fork oil and springs. I then tried 10mm forks raised and it was better. I then tried 20mm and it's even better. My ziptie says it's close to bottoming out (if I land wheelie too hard). What is the max height you can raise stock forks on 2nd gen naked? Also, what causes front to be unstable mid-corner or on exit? If I change lines or purposely press on bars slightly the front will respond with a lot of side-to-side movement (kind of like tank slapper). As far as I can tell on the street, it doesn't run wide. It seems to be better when I lower the front but I can't get rid of it and I can't go any lower on front. Is it springs? Damping? I've changed fork springs to ~0.82kg/mm and changed fork oil to 15W (no emulators) per some recommendations for my weight (150, 165 in gear). Also changed rear shock to GSXR 1k that has a better spring (480lb/in vs. stock 430) for my weight (and damping adjust). Shock length is 1-2mm longer than stock...about 330mm. Sag numbers are in the usual range. I don't have exact numbers w/me. Enlighten me...
Well, I can bottom out a 2nd gen with just 7mm of fork showing under braking... But that's with AK20's. If the AK's don't change the amount of suspension travel, then I'd say you should probably either do bigger/better wheelies, or hit the rear brake a little harder when you get scared from your wheelies.... 20mm was "even better" then 10mm???? Define "better"? What's it doing better now then it was before with just 10mm? You've compromised stability, for rate of turn from vertical to leaned over. You're mid corner instability is more then likely caused by the huge amount you have your forks dropped. Especially if the instability is there when you're under power, from corner exit until upright. I imagine it could be crappy tires, riding technique, or blown bearings. But 20mm is huge, and I recommend no more then 10-12mm showing above the triple. You'll also find that with that huge drop to the front, you've lost some swing arm angle, and will likely run into rear traction issues on mid corner acceleration. You could try shortening your chain, or jacking up the rear to get the angle back. But if you jack up the rear, you're probably gonna get more instability. If you had running wide issues on corner exit, when you had the front of the bike at 10mm, chances are that's a combo of to much rear squat, and rider technique. A little more slow speed rear compression, less rear sag, or a stiffer rear spring could all help. Generally you shouldn't be fixing corner exit issues with the front of the bike. IMHO YMMV BBQ ROFL insert Holiday Inn cliche here...
"Better" in that the front pitches less and bike (front and rear) roll together more. At 0mm of fork showing, I would give it steering input and wait for the front to pitch up and then lean over...felt slow and just wrong. The rear felt like it was just waiting for the front to finish. Once leaned over, an intentional sawing motion of handlebars would make the bike unstable...or if a big bump was hit mid-corner. (I only did the sawing to check midcorner stability.) As I've raised the forks +10, then +20, the pitching is decreased and the bike (front and rear) rolls more together (front doesn't take as long to settle into the lean for the corner). Compared to other bikes I've ridden back to back with the SV (stock CBR F3, Hawk GT), those bikes are much more stable in the corners. Once you think of turning, the bikes lean/roll into the corner without the front pitching...and they feel more stable while leaned over. I agree. Never had running wide issues with this bike. I had it on a 1st gen SV and raised the rear to fix that. The rear on this bike as high as it will go for this shock (barely higher, 1-2mm, than stock shock length) and my preload at rear is like 5mm static/free and 28mm rider if I remember correctly. Not sure I want to go less. It's geometry, springs, or damping, right? Surely riding with a handlebar wouldn't make that much of a difference, would it? If a bike is too much on it's nose, would it feel unstable mid-corner like I describe? I keep thinking SVs are prone to too much rear weight bias and so far, putting weight forward has seemed to help in some regard. I was going to try 20 weight oil or stiffer fork springs. I was thinking maybe the fork is traveling too much and that could cause instability at the front when entering, midcorner, and exiting.
As far as rider technique, it isn't much of a problem if ridden smoothly. Soon as the pace quickens and you start to flick it more, the front gets lively. Other bikes I've ridden don't respond like this at the same pace.
The bike "pitching" has more to do with damping and momentum then it does geometry. Handle bar'd bikes force the rider into a much more upright riding position. Your upper body has a lot of mass. It being up so high, and far from the point of rotation means it has a lot of momentum, and a big impact on the way things work. I bet if you could put your chin on the tank or as close to the steering stem as possible, when you apply the steering inputs, things would quiet down nicely. With the nose slammed to the ground, it should go from vertical to full lean quickly. Which can be a good thing. But the trade off is you have very little trail, as well as a limited amount of suspension travel. With your geometry the way it is, as soon as you open the throttle when exiting a corner, as the load comes off the front wheel, the tire starts "skimming" the surface, instead of being well planted. At that point it's like the wobbly wheel on a grocery kart. Any little input by you, the wind, or the imperfections on the tarmac are going to cause it to flutter. Also being a handle bar'd bike, you have a lot less weight over the front keeping the tire on the ground, compounding the issue. In addition, you have a lot more weight on the back, which is also compounding the issue. Putting weight on the front wouldn't/shouldn't necessarily cause a stability issue. The drawback to weight on the front wheel is more along the lines of exceeding traction while trail braking. I feel pretty confident in my internet diagnosis that weight on the front wheel is not your issue. I've never ridden an SV with handlebars. So I'm reluctant to offer to much opinion on what the issue is, regarding stability under initial steering input. It sounds to me more as though it's something inherent to the design of the stock bike. None of my SV's ever had that issue. But they didn't have handlebars. In any event, there's only so much you can do with the stock fork suspension. If it was me, I'd get the traxxion gold valve kit, and put thicker fluid in the forks. Then I would start thinking about changing my riding style at that point, specifically body position, and the position of my head relative to the bike before making an input.
thats actually a pretty common issue with their stock sv ak20 valving. they just dont listen to me anymore. i fixed chris slay's problem last year on his ak20 forks, as his were bottoming too. i run a different setup in mine thats much stiffer than their normal stuff, and my stuff rocks. i also run a diff oil level than they like. martin makes fun of me, but it all works and those that i've done it to like it better too.
Did you run heavier springs then they recommend? I've had a few SV front ends done by traxxion, and I swear they underestimate us SV guys or something, because they've always been a bit softer then I'd like. They did suggest I add more fluid though, to fix the bottoming issue. So I'll give 'em that much.
Thanks, Biz. I've tried to lean further forward on the bike but I can't tell a difference on the street. Where the handlebars are at, it seems like my weight still is on the seat and in my legs/pegs. After riding it again and doing some thinking, I'm leaning towards lack of rebound damping up front. I measured sag tonight in my street gear (168lbs): front static/free 22 rider 37 rear s/f 8 rider 30 I think the springs are fine and the rear of the bike feels fine (pretty much planted at all times...nice in other words). Fork oil isn't too hard to do again so I'll plan on that next. If the compression damping is too stiff after the oil change, then I'll have to consider going with emulators. I've spent less than $50 so far to get it to where it is (shock $30, cut springs $0, and whatever the fork oil cost). In the meantime, to make sure I'm not bottoming out, I'm going to lower the forks to 15mm over the clamps and try that. The preload adjusters have about 12mm of adjustability so that should help. I've looked at the fender and don't see any marks. The ziptie is against the lower triple clamp though.
I had mine at about 14mm above the triple clamp and was spinning the rear on occasion. Using crappy scales to weigh the bike i was about 20-25 lbs heavier in the front than the rear. i raised it to 12mm (Traxxion's recommended maximum) and brought the geometry back closer to 50:50 with only a 5 lb or so difference. i weighed it over and over both ways and i believe it really did make that big of a difference. I notice the change big time. It doesn't turn in like it did, but the rear is absolutely planted at the apex when i roll open the throttle. I think 15mm is too much even with the ride height on the shock all the way up.
Good to know, jmanley. I'm sure if I took it the track the change would be more noticeable. I actually tried the bathroom scale thing a few weeks back. One scale was about 6lbs off from the other. At +10mm on the forks, weight bias was front: 190lb (46%), rear: 220lb (54%). I jumped to +20mm a few weeks later, so I don't have bias for that change. I think track/race bikes are running 340mm on 2nd gen SV shocks so with mine at 330-332 it won't be as good as it could ($30 vs. $700 shock). I think that's why it does better with much lower front. Mid-corner, with street tires, I can feel the front and rear squirm about equally. Haven't had the rear slide yet.
