ok, not being up on the latest in tires for my 83, got a 120 80 18 bridgestone battleaxe, while there at the salvage yard went out and found a wheel off another model, the tire mounting width was wider than the vision wheel. I took it home with 130 80 on it and still had more room.
the stock vision is 110 90
the new wheel takes 120 80 18
question is how wide on the wider wheel can i go , and and is this being a bolt on, worth the effort. the tire is all it will cost if i make the swap
I'm curious as to what shaft drive Yamaha, the wheel came from . Any idea? Jason, can you comment?
Me too, and isn't the Bridgetone Battlax a radial? I haven't tried radials yet but I'm pretty sure I'd want them on both ends when (if) I do.
it came off a 650 turbo it looks identicle but has about 1/2 inch wider wheel where the tire mounts and uses drum and its shoes are wider than the vision
Then it's a matter of swingarm & fender clearance...
it had a 130 80 on it,was the same height inflated as the stock vision combo when i slipped it in and measured side of wheel to swing arm then noticed over 1/2 inch on the tire side clearance ? now is the extra brake and wheel combo worth buying the tire
metz compk 100 80 18 on the front it does not show whether it is radial anyone know
Yes, the wheels on the Seca turbo are very similar to the Vision . I would at least price the brake backing plate and if its not to much I'd get it . Give us the complete number from the tyre and I'll investigate .
The Bridgestone Battlax is available as either a bias ply or radial. The BT-56 SS Ultra Hi-Performance is a Z speed rated radial. The BT-45 Sport Tour is a bias ply available in either H or V speed ratings. You can tell a radial from a bias ply by reading the letters in the size description of the tire. A radial will always have an "R" designation after the speed rating. Thus a 110/70 ZR 17 would be a radial with a speed rating of 149+ MPH. A tire marked 110/70 H 17 would be a bias ply with a speed rating of up to 130 MPH.
Tire basics - Most tires today are measured in the metric formula. Automotive tires follow the same formula. Less common are alpha and inch - both are more common on dirt bike tires.
The first number is the height of the tire as measured from the rim to the highest point on the tread.
The second number is the aspect ratio or width compared to height. (I've forgotten the equation to obtain the ratio - too many years & beers since my days as a tire tech.) The smaller the number, the wider the tire (a 110/90 is narrower than a 110/80).
The final number - after the speed and carcass type (radial or bias) is the rim size.
Speed ratings are as follows:
S - up to 112 MPH
H - up to 130 MPH
V - up to 149 MPH
Z - over 149 MPH :o
I haven't looked too far as yet, but I haven't found a radial in the sizes that would fit a stock rimmed Vision. Might be a fun search on the various manufacturer's websites.
One other measurement to consider when upsizing the rear tire is the clearance between the center of the tread and the exhaust collector in front of the rear tire. My 120/90H-18 comes closer than I'd like. A 130 may be too close - not likely a problem when moving but the heat when parked after a good ride might be very hard on the tire.
Hope this info helps clear up some tire sizing questions.
curious,
the specs for the 650 turbo on this page list the wheels as the same in the rear and a 19" wheel on the front.
http://www.xjowners.com/info/secaturb.html
you might want to check out the description of this ebay ad.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=35601&item=2432557572
and possibly this one:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=35601&item=2432557936
-Ron
h20: Your observation about 130 clearance between tire center and collector is astute and slightly flawed. The clearance problem there DOES occure at speed. Years ago had a brand new 130 something on the back of my '83 when I came up on a gaggle of Ducatis'. They took off and I decided to see how hard they wanted to play. Went for top speed and much to my surprise and dismay was only able to see 85mph. At my next stop I was amazed to see lots of powdered rubber in the swing arm area and small chunks of rubber missing from the highly polished center of my new rear tire. Diametric expansion due to centrifugel force was the cause. Due to $ issues, I rode that tire for another year, but never at more than 85mph. There was also a tolerable contact issue with with driveshaft swing arm.
Bottom line 130s' are over the line. Cheers.
I stand corrected. I forgot about the tendency of centrifugal force to expand tire size. I still don't like cooking one spot on the tire like that, though.
the 120 80 18 is 3/4 inch from ex, the 130 80 turbo wheel looks to be the same in the 83 frame i am working with, i have not dismounted the tires and measured there tire mounting width so if the brake is the only advantage to the swap and not a better tire selection its cons outweigh the advantages so i may take the 120 80 18r battleaxe back and exchange it for something to go with the nos compk metz 100 80 18 for the front .
by the wayQBSwhen you changed the tires back what top speed would you run, my 83 will bury the needle to the peg
rrp: My '83 will hit red line in fifth gear, an indicated 113 mph. No way you're actually hitting beyond 140 mph. cheers.
my speedo will move past the 140 mark but usually to busy to notice but on the flat freeway around here with 90 90 18 cheng shin tire on the front and dunlop 491 belted mp85hb18 on the back went on road trip and hit those speeds no sure now how stock the bike is had it for 5 years, and would always turn that speed. I got that top end apart now and will look it over really close.
Buy the way any one ever figure out the camshaft's # for the years 83
My '83 would do probably 110+ when it was new. If yours is going 140+, you would be turning around 12,500 rpm in 5th. It would also be making over 90 hp, stock is 67.
ok, i do not believe my bike was stock because i can hit those #, now I have the machine apart and would like to know if anyone has messed with there cams (stock stuff) And begin to measure this stuff while assembly, maybe find out more of the differances i can show this live but my vision broadcast got me in trouble last time and at those speeds how accurate are these instruments
Just as a note (and a bit of physics). If the bike in question does 140, and the top end of a normal bike is 113, then the needed horsepower is 102+, not 90.
140/113 = 1.24 (rounded)
since you need the square velocity ratio times the horsepower (takes 4 times the hrosepower to do twice the speed), this means you need 1.54 (rounded) times the horsepower.
Multiplying this by 67 ponies, gets you to better than 102 ponies to get a vision to do 140.
Just a minor tangent on motorcyle top ends.
Brian
That would be assuming the top speed were horsepower limited instead of rpm limited. I had an '85 FZ750 which had a top end of over 140 and it had about 87 hp. It would hit the rev limiter in top gear pretty hard. I can honestly say that I was not looking at the speedo of tach all that much but I could certainly feel it when it hit the rev limit.
Yes, assuming the bike could rev high enough. Also, this calculation is for a single Vision, if you were suddenly able to pump in 102+ HP, you might have a chance to do 140, it would probably take more. This example could logically be expanded to most Visions of the same build (fairing, dual disks, all the draggy bits...)
An FZ750 at 87 HP is a much different beast than a Vision with 87 HP, like comparing apples and oranges actually... Or maybe Apples and Cumquats, I don't know.
An FZ750 is probably a less draggy bike than the Vision is :-)
Brian
V Max ??
maybe the 83 speedo is inaccurate
The 82 sure are , although they read slow , and it gets worse the faster you go.
I came across this topic while looking for the vision's stock wheel width front and rear. As far as needed horsepower goes, perhaps yall remember the vincent black lighting, certainly no more aerodynamic than our V's and it made roughly 75-80hp on race gas. Our top speed is limited by gearing. I can (I've never done this mom... I swear!) hit redling in 5th gear, that's about 113mph. With a taller gear, a higher speed could easily be achieved. Anyone have a euro gear set, and want to loose your life liscence?
Or does anyone have one they want to sell? I've got a long distance butt-burner coming in a few months, I wouldnt mind the higher cruise speed/ lower rpms
Here's the famous picture of the Vincent with Rollie Free riding in no leathers for "aerodynamics"!
http://www.motorcycledaily.com/101502rolliefreesmall.jpg
(http://www.motorcycledaily.com/101502rolliefreesmall.jpg)
Rex,
Isn't that a photo of you trying to get to Sonora ???
Without a faring, you'll be happy to crawl off that V after a full day at about 80 mph with your "bobble head" still attached! ;D
GlennW
HAHAHAHA I find that a nice speedo is the best high speed long distance touring gear, Aerostich be damned! ;)
H20 got himself a full fairing, so he's selling me his shark fairing and crash bars THANK GOD. I'm going to get some highway time, and some long distance rides under my belt before setting out on my "adventure". I might fab some extra wind protection out of lexan, maybe some lowers of some sort, and hand guards... not sure, I've got access to a whole load of fabricating equipment so I can do a lot.
rip_brotz420,
Does the 650 turbo's rear wheel center correctly? If I remember correctly, that rim is 2.5" wide (the Vision's is 2.15") . Most tire manufactures recommend a minimum of 2.5" for 120 tires.
If the Turbo's rim lines up correctly I would recommend a 120/80 rear with a 100/90 front. You may want to lower the forks by 1/4 to 1/2" (1/4 to 1/2" above, instead of flush) to level the bike, if you have an 82 Vision.
Ride Safe,
Dale
First :The rear rim size is cast or stamped on all rims back in the 80's...somewhere. The Vision is a 2.15 width...cast. With a Metz ME55 120/90 is on my '83 with euro gears. A 130 is not a good thing on a Vision. My difference in top speed is slight due to the modest horsepower an wind drag(I have added a small wind deflector). NOW at 113mph the tach sees ~9300 instead of 10000rpm. Both the tire being a 120/90(120/80 is actually shorter than a 110/90) and the euro gears just affect how long it takes to get to 113mph. If I give it more room without the deflector on, 115+ is likely. It is basically geared for 120+ now. I also have a truly calibrated digital speedo that is VERY accurate. Officer "Friendly" has confimed this.
Jason,
I know that many of the Vision owner run 120?s on the rear but many of the manufacture recommends 2.75? and all the listings that I have been able to find show 2.5? rim for 120 tires.
If the Turbo?s rear wheel will line up correctly, it would be a nice upgrade for the brake and a rim that meets the minimum recommended width for a 120.
As for adjusting the forks to level the bike, the problem is that the 100/90 front is taller then the OEM 90/90 and as you pointed out the 120/80 rear is slightly shorter then the 110/90. Adjusting the forks is one way of leveling the bike.
The other way to adjust for a 100/90 for is to mount a 120/90 on the rear. That will also level the 82 Vision.
Ride Safe
Dale
The '82 and '83 use the same rims but the '83 come stock with a 100/90 in front. So the 100 in front is not an issue. Unless you have a 90/90 in front. Which is a minority.
I agree a 120/90 in the rear is bigger than recommended. But you are only talking about 9mm higher when putting it on the side stand. As far as handling. I have a 110/90 on my '82 and the 120/90 on the '83. Yes the '82 steers slightly quicker. But they also have 2 different brands of tire. Others have not found issues with the 120/90 in back. Just don't run too much psi. Bottom line a 130 will not be the way to go...too wide. You gain next to nothing with a 120/80 which is shorter sidewall and less diameter than the stock 110/90. If you have a 90/90 in front? go to a 100/90. Then all will be beautiful with a 120/90 in back. I have not checked the Turbo rear wheel size. But a guy I saw with one had only a 120/90 on the back. I have an old cycle world with the Turbo specs. I'll check.UPDATE: Cycle world specs don't show wheel size on a Turbo. But the tire is a 120/90. So the rim is likely a 2.5" The Vision won't take a 130 without chancing the tire hitting something. So no matter what. A 120/90 on back is as big as one should get.