| Author | Message | ||
     Nattyx1 |
GPR Steering damper - I had no idea how much work I was doing to keep the bike online till today. Just to double check myself, I ran a series of 40 good tight canyon corners on a favorite road. I disconnected it, ran em again. Without it: slower, busier, in fact, scarier. With it, smoother, less effort, more graceful, faster. Supercorsa tires: YES. More on that later. | ||
| Xtreme6669 |
Just curious.. what did you set it to? | ||
| Northernyankee |
Arghh, I am jealous that you are even riding. Today was the first day above freezing in over a week! That is the one of the biggest reasons that I miss SoCal, that and the MM. (Message edited by Northernyankee on January 16, 2011) | ||
| Duphuckincati |
6669, I'm just as pleased with mine and have not felt the need to go over #5. Yankee, I see you're in NJ, I left there for Central Cal and you have my sincere condolences. What's the MM? | ||
| Xtreme6669 |
Yea I have been running mine at 3 but was just wondering what the masses are doing..? | ||
| Northernyankee |
The MM s a medical product. | ||
| Froader4life |
I like mine on 8 or 9. It's kinda scary to see how much the stand-off mount flexes on 20. The damper works awesome, just has way too much branding. | ||
| Duphuckincati |
Ah yes Yankee, of course. Now I REALLY feel for you. If it's any consolation, at least you have da' kine pizza. | ||
| Nattyx1 |
Settings: For baseline, I set the bike to factory specs for my weight (with gear, etc). I ran the GPR at ZERO when just rolling around/mellow riding and even there (where "zero" is still "something" over not having it at all). I put it at 2 when I was hard on the gas at bumpy corner exits... I never needed more than that on the street, but then I was still a good 5-8 degrees short of max lean angle and never accelerating at full power (10k rpm) from corners. That's track stuff, and so it's possible it'll need to be bumped up a notch or two for that. The thing goes all the way to 20 -- I'm hard-pressed to imagine a situation where someone might need their front end pretty much locked solid (LSR at Bonneville? Doing Stoppies in a stunt show?) Install: 5 minutes. First thing you notice is how well it's made. Second thing you notice is all the complicated metalwork... the compound curves... the nice milling -- Supports the pricing. There's that old cliche "the bike feels like it's on rails"... but it applies here. Pick a line - it stays there. Decide to change your line, no problem the bike still steers quick, it just isn't doing anything without you "asking" it to. So now it now seems to be making the best possible use of the steep steering head/stiff chassis/short wheelbase without the concomitant "nervous" behavior. There's no hunting and pecking at all (again, I must have just accommodated for this and got used to it. When I went for a ride with my friend who brought his fully sorted Zx10 and we traded bikes, we both noticed this twitchiness on my CR. He pointed it out first of course... and I immediately rankled. But getting back on the CR after his quick-turning but dead stable zx, I realized he was right. As an aside... You CAN settle the front end on our bikes a bit by stiffening the rear (the front end will "dance" a bit on hard acceleration if the rear is set too soft - I told a story about this in my Buell training sessions about the first time I rode an 1125R in 2007 at Blackhawk). Now is this bad science? Am I erroneously leaving out the fact that new far stickier tires were installed, and the rear has a bigger contact patch at full lean (sorry to be argumentative, but the 190/55 DOES have that over the stock size - plus zero fat rain sipes at the tire edge mean no tread squirm). Clearly these made a difference, but the comparative test I did by removing the damper on the same stretch of road answered the question. the bike was definitely better than before with these tires in terms of absolute handling ... but exhibited much the same behavior as before. With the damper, ... well, I've already said what that was like. Downsides: 1-it will make the bike harder to roll around/park in your garage etc. 2-it can mask bad riding techniques like hamfisted throttle inputs --pulling the throttle side of the bars toward you when accelerating (do you tend to move to the left when you leave a stoplight in a hurry?) --overcorrecting in turns from having eyes that are too ---busy looking around/distracted and not focused on corner exit, --inadvertent steering inputs from too tight a grip on the bars, --Improperly set-up suspension, etc.. These things matter a lot (in general)... and more so if you all of a sudden get on a bike that doesn't have a damper. Bottomline: If you own a CR, buy one of these and install it. Period. But don't let it be a band-aid for things you should be working to improve (I've promised myself I'm not gonna get lazy with this stuff). Last - a location shot from the Rock Store on Mulholland yesterday. Bikes were parked along the road at least a quarter mile in each direction because the lot in front was full to capacity. Apologies to all you snowbound people...   | ||
| Nattyx1 |
Oh and as I was leaving, I saw Wild1 -- we spoke for a minute but I had to roll out to get home. Thanks again to him for donating his bike for a few weeks while GPR sorted this out for the rest of us. | ||
| Jdugger |
Natt, Take a picture of your rear tire from the top, would you? I wanna see how that 190 mounted up on your wheel. I'd LOVE to be able to run 190s if the profile will come out right. | ||
| Ljm |
Hey, Steve, Pardon the dumb question, but how does it attach to the frame. Looked on the site and can't tell exactly and have never seen one in person. Thanks, Larry | ||
| Parrick |
Nice write-up Natty. +1 on Ljm's request. Maybe a pic or two? The website pics don't give a very good angle on the frame attachment point. | ||
| Mackja |
GPR has a small mounting bracket that bolts where the right front air box screw is located and then has a s shaped arm that comes over from the damper and is secured in that mount. | ||
| Smitty1125r |
Notice the bike in the background...look familiar? http://www.youtube.com/watch?v=RP-UfUrymY4 | ||
| Nattyx1 |
Hi. Ok for whoever asked... here are some pix of GPR installed... I added some explanatory notes.      | ||
| Nattyx1 |
And for jdugger etc... here are some pix of the 190/55 installed... I added a note on one of these too.    | ||
| Mountainstorm |
Nice picture tutorial on the damper and who'd a thunk it a 190 fits. Any advantage to that? | ||
| Luisemilio25r |
Does anybody think that the mounting point on the frame is a bit weak? I mean, it is aluminum and there isn't that much thread. | ||
| Nattyx1 |
Shawn higbee ran a race spec 180 and a 190 back to back on the stock rim and found he had "5percent" more side grip and better off corner drive. Good enuf for me. And as for the gpr mount? Yes it concerns me. I bet if you ran it stiffer than 8 or 10 you'd eventually be looking at tapping a bigger threaded hole for the next size bolt. I also bet that a crash where the front end experiences a quick violent deflexion would either snap the bolt or more likely rip it from the threaded bore. That said, imho you are less likely to have a crash in the first place with one of these installed... | ||
| Jdugger |
There's no debate that a 190 offers more contact patch when mounted correctly. It's a bigger tire! When I tried 190s, unlike Natt, my tread was way past the bead seat, and that's what messed up the profile. I'm gonna order up a set of Supercorsas and try again, though for 2011 there is a (contested by my tire dealer) rumor going around they dropped the 190s and only offer 180 and 200 series, at least in the race compounds. I suspect in the SP they will continue to offer the 190. They are offering a 180/60 now, though, and that should also provide some extra tread area. (I think) (Message edited by jdugger on January 18, 2011) | ||
| Nattyx1 |
Shawn higbee ran a race spec 180 and a 190/55 back to back on the stock rim and found he had "5percent" more side grip and better off corner drive. Good enuf for me. Also, not all 190/55x17 tires are the same. Each mfer has its own ide of sidewall height, stiffness and overall curve shape. I like how pirellis feel. You might like how dunlops or michelins feel. Lucky for us, there's no spec tire rule in the real world. :-) And as for the gpr mount? Yes it concerns me. I bet if you ran it stiffer than 8 or 10 you'd eventually be looking at tapping a bigger threaded hole for the next size bolt. I also bet that a crash where the front end experiences a quick violent deflexion would either snap the bolt or more likely rip it from the threaded bore. That said, imho you are less likely to have a crash in the first place with one of these installed... | ||
| Blake |
>>> There's no debate that a 190 offers more contact patch when mounted correctly. It's a bigger tire! Now you've gone and done it. | ||
| Nattyx1 |
Gone and done what? | ||
| Blake |
Tire pressure is more of a factor in contact patch area than anything else. You know those top fuel dragster tires with the massive contact patch and around 5 psi? If you put 30 psi into them the contact patch will shrink in area by a factor of 30/5 = 6. The same is true for a motorcycle tire. A tire, as long as it isn't resting on the sidewall, supports the weight it bears through the pressure acting upon the contact patch. So, if the rear tire of motorcycle with rider is supporting 300 LBs and is charged with 30 PSI, then it's contact patch at that condition will be 300 LB / 30 LB/IN2 = 10 IN2 When accelerating or stopping with most if not all of the weight being borne by one tire, the contact patch increases in area accordingly. That said, there is a transition band around the circumference of the contact patch where the meager stiffness of the tire gives some additional support. But you can characterize the amount of that support by taking a tire/wheel with valve stem or core removed to keep tire gauge pressure at zero, and push down to get about the same contact patch as when inflated. How much do you have to push down to achieve it? Not much, maybe ten pounds, if that. That is the portion of the load that the tire carcass itself is supporting. All the rest is borne by the internal pressure. Physics is fun.  | ||
| D_adams |
Does that mean I need to get me one of those 300 size tires now?!? Sh!t | ||
| Blake |
>>> Gone and done what? Raised the dreaded specter of tire contact patch. ![: ]](http://www.badweatherbikers.com/buell/clipart/proud.gif) It's an old joke here relating to some vigorous debate some years back. "Counter-steering" is another. Fun stuff!  | ||
| Jdugger |
I was making an "all things being equal" comment... I really struggle with tires, honestly. It's taken me a long time to find a setup I like, with tires that don't tear to pieces. I'm so keen on the Diablo Superbike Pro right now. It's an "amateur" tire, but I've set every personal best I have at 3 different tracks on it. They last, and last, and last, and last... | ||
| Blake |
>>> I was making an "all things being equal" comment... I know. Counter to our intuition, it isn't true that a wider tire provides a larger contact patch. Wild huh? | ||
| Blake |
Are those slicks or DOTs? I used to poo-poo the extra cost of slicks, but a friend of mine says they do indeed make a significant difference. |
