| Author | Message | ||
     Socoken |
there was a conversation a while back about putting new tires on a bike and it being harder to wheelie. it peaked my curiosity, so i did a little homework. first, i bent some wire, a coat hanger, to match the profile of my wore out tire, still on the bike, then did the same with the new one, on the bike, and cut it at the edge of the tread. the difference in profile was 3/8". so the radius of the tire would be 3/8" shorter, and the diameter would be 3/4" different. sounds like radical numbers, but thats what i got. | ||
| Socoken |
next, i found a site with a speed calculator, given Dunlop's numbers for 208 dia (170 60 z r17) of 24.96", speed at 4000 rpm is 82.16mph in fifth. with a 24.21" dia tire, speed is 79.69. so the difference is about 2 and 1/2 mph at 80. not a big deal. the difference is closer to 2mph at 60. speed with the new tire, 24.96 and 27/60 pulleys at 3000 is 61.62, whereas with the 24.21 tire, it is 59.77. now, speed with 26/60 gearing and a new 24.96 tire is 59.34. so, going from a new tire to an old one, is comparable to dropping a tooth in the front pulley, thus making the bike easier to wheelie. feel free to correct me if im wrong somewhere. Ken | ||
| Phillyblast |
Wheelies??? What are they? You keep both tires on the pavement where I come from, and you'll like it! Dang boy, this be the old school S2 stock sporty motor gray hair bald spot hey you see that old trumpet college tuition for the oldest is killin' me that dang XB is too tiny for my tired old knees section . . . sorry, got off on a bit of a rant there. Happens at my age.  The new Avons on the dog ••• slow S2 are a bit taller, so they turn in better far as I can tell. The Bonny board had a thread about that, the tall profile designed for quick turns at speed affecting straight line stability and such, so I don't doubt the #s. hmmm. interesting. | ||
| Mikej |
"Dang boy, this be the old school S2 stock sporty motor gray hair bald spot hey you see that old trumpet college tuition for the oldest is killin' me that dang XB is too tiny for my tired old knees section . . . "  I don't think that would fit in the subject line, but it was definitely worth repeating. Thanks. And how many times did you have to take a breath while typing that?????  | ||
| Phillyblast |
Take a breath? I had to take a nap!  | ||
| Phillyblast |
Well, I guess I killed the Old School board with that little rant. Hey Ken - I was kidding! | ||
| Firemanjim |
David,take a break,go ride the Old School Buell.Are you coming to Bonneville???How's that good looking girl?? | ||
| Blake |
I think 3/8" of tread is a bit on the liberal side of that measurement. But your physics is sound. Don't stunt riders often run with lower air pressure in the rear tire? That might be for the same reason. | ||
| Phillyblast |
Jim, Rained again today so I took the cage and the GLG down to DE to pick up her wedding band - *bling*. Picked out my band - titanium No Bonneville for me this year - wedding is 10/2. I was still going until a friend of mine decided last month he's getting married in Chicago Sat. the 18th. Got a supersecret plan for next year floating around the space that used to house my brain, though. Hey, shouldn't you be out shortening con-rods or sumpin'? | ||
| Firemanjim |
Naw,the nice UPS man brought the right length rods yesterday and they are back at the balancers getting refit/rebalanced.Maybe next week I can put a damn engine together!!!!!!So I went to work more OT to pay the nice man. | ||
| Socoken |
Blake, you cant just go around accusing men of being liberal, thems fighting words where i come from. 3/8" is what i got, and i did my best to be as accurate as possible, i didnt go through all that trouble to guess. i thought stunt riders went with lower pressures to make wheelies more stable, or controllable from a side to side balance point, but i could be wrong. | ||
| Rocketman |
Where's Dyna?  Rocket | ||
| Rocketman |
Scrubbed!!  Rocket | ||
| Blake |
Rocket, I didn't think you had it in ya. Good job economizing your tire use. Leave no rubber unused. | ||
| Rocketman |
Those pic's aren't very good exposure! In the flesh you can see the blistering and the frilly edges <grin> I'm really on top of the 916. I think I've said it before, but when someone tells you a 916 is a fantastic handling bike, you won't notice how fantastic until you've grown accustomed to the ways of the Italian stallion. I can take various radius curves at high speed and pull on the opposite side bar to the curve and really feel the counter steer working. I know how the racers back them in that's for sure. What you have to remember is this thing accelerates damn near as quick as an 04 R1 but it has that low down grunt of a torque laden twin. Give it some stick out of a very quick corner and it will lift the front wheel high whilst on its side. Even when the rear is squirming you can feel what's going on. It's a very rewarding bike to ride very fast. I can't imagine how great an S1 would feel with this kind of power. Just totally awesome comes to mind - like a 916. Blake, you need to get one of these on the track at all costs. Rocket | ||
| Phillyblast |
Hey Sean, can you turn left, too? Nicely done - is that from a track day? | ||
| Reepicheep |
Nice Rocket! Your cameras automatic exposure and focus system is being fooled... it is focusing and exposing on the stuff in the background (pavement, hub, chain) and messing up the stuff in the foreground. Some of the better cameras have alternate exposure modes. The best is a spotmeter mode, you put a small square in the center of the viewfinder on top of the center of interest of the photo (in your case the tire, for people go for the eyes), and push the shutter button down half way. The camera will then calculate the exposure and focus for that point. Then (still holding the button half way down) move the camera to frame the whole image in a pleasing manner, and press the button the rest of the way down to actually trigger the shot. This also has the perk of changing the latency of many good digital cameras to effectively zero. If your camera won't do this, sell it or give it away and get one that will (*cough* nikon *cough*). I would rather have my old Nikon 950 1600x1200 (probably $150 on ebay these days) that has this feature, then some new gee whiz 5 megapixel wonder that lacks it. Sorry to interrupt your offtopic Ducatti thread with an off topic Nikon thread | ||
| X1glider |
Grrr...had to edit out my badly misjudged post. (Message edited by x1glider on August 17, 2004) | ||
| Rocketman |
You want the left? You can have it!  Eat your hearts out Remember, you turn right on a roundabout in the UK. That's the easy bit! Nope, not had the 916 near a track yet. Maybe one day. Rocket | ||
| Lornce |
Oi Sean, Bring yer chi-chi 916 along to Mosport.... I've got summat to show ya....  | ||
| Rocketman |
Lawrence, you know if I ever bring a bike to your side of the Pond, it would be my Buell. The 916 is perfectly happy around your old neck of the woods thank you You think I'd want (a skinny rake like) you showing me up on the track anyway! Rocket (Message edited by rocketman on August 19, 2004) | ||
| Lornce |
Skinny rake?!? Not me mate. I'm runnin 210 these days. It'd take another trip to Asia to get me back to 190 where I belong.... Good on you for having the sense to land a tidy 916. Brilliant bikes, no doubt about it. Would love to put one around Mosport with anger. Hey, aren't we supposed to be talking about tires or summat on this thread? Errmn, Dunlops. Dunlop 208GP's for track use. Once you've run on DOT race tires you'll want 'em on yer street bike too. Are those Pirelli Super Corsa's on yer 916? Pretty tough to buy a bad tire these days. Heck the Bridgestone 020 "touring" tires on the S2 provide more corner speed and predictable slide feedback than the old bias ply sport tires we used to run back in the day. Mutter mutter mutter.... | ||
| Crusty |
Remember when the K81 Dunlops were king? | ||
| Lornce |
Oh man, K81 TT100's! Had 'em on my SR500 Yamasingle along with girling shocks, clubman bars and a bikini fairing (17 and goin for the Guzzi LeMans look without the LeMans $$$) Never dropped that bike as a result of insufficient traction. Dropped it once out of excess stupidity, but never insufficient traction.... Come to think of it, I still have a Dunlop bias as a result of those early +ve experiences. This threads about wheelie tires or something though, so I'm gonna shut up now cause I don't have the wheelie gene. Dirt bikes? Sure. Big heavy street bikes with delicate shifter forks and tender engagement dogs? Not this guy. Not without a knoll, anyway.... | ||
| R1DynaSquid |
That aint 5hit Rocket. Hell we even scrubbed the front tires all the way to the edge today. Nice little black balls of hot sticky rubber all over the edges of the front & rear tires. | ||
| R1DynaSquid |
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| Rocketman |
I scrubbed mine on the street Dyna! Rocket | ||
| Lornce |
I think Rocket needs help with some of his pent up aggro.  | ||
| Rocketman |
She's bloody gorgeous Lornce! One of yours? Rocket | ||
| Lornce |
Nah, she belongs to a bloke out your way. And she's got a sister.... L | ||
| Rocketman |
.......in a ho' house? Bahahha Rocket |
