Guzzi2Go Posted October 23, 2009 Posted October 23, 2009 It seems like wheelies cause speed wobbles!Helmet cam Nothing one can't fix by properly adjusting steering damper during "landing".
docc Posted January 3, 2014 Posted January 3, 2014 PLEASE NOTICE: I decided to redirect "Silly Banter" to the silly banter sub-forum and make a final attempt to return this thread to sorting out some significant technical issues especially with regard to the steering damper and the changes in geometry of the early Sports. There is some really valuable information in this thread, but it's nearly impossible to find. Back on topic. 2
helicopterjim R.I.P. Posted January 4, 2014 Posted January 4, 2014 " The later triple clamps include a 1/2-degree of cant compared to the steering axis. Now this has me thinking ..... he doesn't mention which way the forks are canted. If they are canted forward then that will reduce trail and increase instability. So I am thinking then that they are canted back - or steeper - as this will increase trail and increase stability. Since the steering head remains the same ..... the forks actual rake doesn't change - just the angle of the forks. Here is a link to a chopper page that actually describes canted triple clamps. http://www.seegercycle.com/Rake-and-Trail.aspx
Kiwi_Roy Posted January 5, 2014 Posted January 5, 2014 On the few occasions I have tried to use the damper, it's scared the ____ out of me when I try to steer at low speed. If they made a damper that cuts out below say 30 mph, then I might use it.
sp838 Posted January 5, 2014 Posted January 5, 2014 I don't have this problem at low speeds, but it's possible that mine is a purely decorative, ornamental steering damper… (I haven't tried the whacking thing.)
AndyH Posted January 5, 2014 Posted January 5, 2014 I was just thinking the same thing. Always felt steering dampers had a tendency to make low speed handling sluggish to the point of fally-offness in car parks etc. and so figured mine must be f***ked. Anyway, doesn't waggle at speed so I follow the principle: 'ain't broke, don't fix!'
docc Posted January 5, 2014 Posted January 5, 2014 I have been admittedly lost on the triple clamp change. It explains why I had never seen an early Sport with a front axle screwed directly into the fork leg until LowRyter came to the last Spine Raid. It would be interesting to compare upper triple clamp numbers as I can't see any difference in the clamps' finishes or appearance from the photos.
LowRyter Posted January 5, 2014 Posted January 5, 2014 On the few occasions I have tried to use the damper, it's scared the ____ out of me when I try to steer at low speed. If they made a damper that cuts out below say 30 mph, then I might use it. actually they do make electronically controlled dampers that do that. You'll have to google it. BTW- I have a red frame, it can be a little twitchy but I never even touched the damper. Anyone know some ballpark settings? Also, my EV has a cheap friction damper. I've taken it apart before and fixed it. I am not sure it adds to stability but it give better "feel" as the fork doesn't feel like it's flopping around in the parking lot.
docc Posted January 5, 2014 Posted January 5, 2014 So, here is where the part number is (between the mounting for the ignition switch): While my serial number (1126xx) is under the 113032 change referenced in the Service Bulletin, and I have a nutted axle, this is the part number referenced as the later canted triple clamps (501 452). LowRyter, where is your serial number in the range? Can you see that upper clamp part number?
docc Posted January 5, 2014 Posted January 5, 2014 [A cross post from "Early special V11" on the 24/7 V11 sub-forum summarizing a few of Greg Foield's previous posts in this thread regarding the change of triple clamps]: A post by Greg Field regarding the change of triple clamps, but not just for the Rosso Mandello, but by serial number: "What is meaningful is a discussion of triple clamps. Early (to frame 113032) bikes used triple clamps with 1/2 degree steeper rake. It is these that show the greatest tendency to instability, though even the later ones sometimes do, too." With this clarification: "I'm pretty damn sure the steering angle on the frame was unchanged from beginning through the last pre-LeMans bike. All red-colored frames have the same part number. The part number was changed for the Rosso Mandello because it is coated black. The angle change was made in the triple clamps at the frame number listed earlier." And further clarification here, on post#164: " The later triple clamps include a 1/2-degree of cant compared to the steering axis. These gray "canted" triple clamps were used through the end of the red-frames. In general, if your red-frame's forks have an axle nut, they also have the early non-"canted" clamps and if your red-frame has an axle that screws directly into the fork leg, it has the "canted" clamps. There is some crossover between axle-fixing arrangements and clamps, though, and Guzzi offered a kit of the "canted" clamps for people who wanted to reduce twitchiness of their early bikes, so any combination of parts is possible. Rosso Mandellos had black "canted" triple clamps. Starting with the LeMans, Guzzi again fitted non-"canted" clamps, but they were painted black." And these part numbers under the upper triple clamp, again apparently not unique to the Rosso Mandello: "Does it read "01493100" or "01493130" (both early) or "501452" (most late)?"
thumper Posted January 6, 2014 Posted January 6, 2014 Some offer a active damper, in that the faster the bars wobble the more dampening pressure is exerted. BMW uses this on the K1200LT. On this bike if you take your hands off the bars and hit the smallest of bumps a front end shake will happen, the damper kicks in and it does not get out of hand, this I know. I have taken the electric damper off my 2006 cbr1000rr track bike because at high speeds going into a turn it was hard to flick over. I put a GPR on it and yes I have adjusted it at speed with out a problem. Thing is when you get it set to where you forget it I just don't touch it again. Normally if the front end has started a wobble something bad has happened to upset the suspension, give er a little gas it will be OK. I have a 2000 V11 and have put 20,000 miles on it and to me this bike is as rock solid as any I have ever owned, very predictable and fun in the twisties. Just my 2cents worth on the damper.
sp838 Posted January 6, 2014 Posted January 6, 2014 I've never had any stability or twitchiness issues with my 01 v11, riding 85+ mph on New York streets, roads and highways (ie hell). I have the stock Bitubo damper, not sure how well it works but it's there. What does make me a little nervous is that I'm about to swap the front end. I'll be running 12mm shorter fork legs, with 15mm shorter steering offset, and overall this setup will also be lighter weigh-wise, with narrower fork centers. The forks will have 30mm Öhlins cartridges, radial brakes and my steering will be faster, but might also be a little more prone to wobbles as a result of the geometry changes. I think I will try to fit an aftermarket damper because of this.
docc Posted January 6, 2014 Posted January 6, 2014 Hey, sp838: SN above or below 113032? Nutted axle? Can you make out the number on the bottom of the upper triple clamp?
sp838 Posted January 6, 2014 Posted January 6, 2014 Dunno, I can check tomorrow. The front end I'm putting on is from an 09 gsxr 750. My factory workshop manual says the steering neck on the frame is 26° off vertical. I've measured my stock offset, at 45mm.
docc Posted January 6, 2014 Posted January 6, 2014 Regarding the Workshop manual for the early Sport: I see in Section H, page 10, the angle of 25.0˚. Length at the top of the diagram: 767,203 +/- 0,2 and at the bottom of the diagram: 821,384 +/- 0,2 How does that compare to your specifications? (It appears my manual was printed 03/01 if I can presume that is the date appearing very last on the title page. Is it possible your manual is for the US2002 and later braced frame?) Section F, page 28, shows fork offset of 40,5mm, but like you I get a measurement of 44 mm +/- 1. (Hard to measure accurately).
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