Is 3/4" going to make a noticeable difference?

[Dave8338]

Guess it's time to jig it up, cut and weld. Should be a fun scoot once it's done (next summer). One thing for sure, it'll be the only one on the planet like it. (good or bad) :shock:

Brian: I'll get pics, kinda waiting to see if Santa thinks I need a new digi cam. The one we have now is a true POS.

[p_s]

Old Vespas have the engine and fork on the right and nothing on the left--the idea being that you can mount the spare tire on the side of the road with one wrench:

And it looks much cleaner from the left.
So everyone rides at a 15 degree angle to the left and never notices after the first time until someone points it out and the tire wear marks are off-center. Easily half the weight of the bike is at least 3" to the right and it's no problem. I can't imagine the physics is any different on a heavy off-center motorcycle.

[Dave8338]

Good to know, PS.

[Mark M]

i beg to differ on this...if your back wheel is not in track with your front, you will have a problem..i had the same tracking problem on my KZ440 when i first bought it...it can be very disconcerting too, because it feels alot like headwobble does, only from the rear. It may not make you wreck, but it sure doesnt give you confidence in the stability of the bike.

If the problem is bad enough, it will cause issues. The old Honda Hawk was offset by at least 1/4" and nobody ever complained about it's handling at all.

Mark

[TheCafeKid]

yeah but was the front wheel offset as well? They should always be in line in relation to eachother. Its simple physics.

[Mark M]

yeah but was the front wheel offset as well? They should always be in line in relation to eachother. Its simple physics.

Nope, the rear wheel was offset from the front by the 1/4" amount. Definitely not the optimum situation, but it did work. Considering how loose a lot of production tolerances are, I expect there are a lot of bikes out there with some measurable amount of offset. I bet that a careful alignment to get the rear wheel at least pointing straight at the front would take away a lot of the weirdness, too.

Mark

[Dave8338]

All good points! If you ever noticed (you better have) :shock: that when you climb onto a buddies bike and spend a few minutes in the saddle, that there is a handling characteristic; some good and some bad; that every bike has. I've ridden stuff that you could lay back and fall asleep on (and the size of the bike has no effect other than to exacerbate the characteristic) and others that you had to man handle in every maneuver.

I'm going to set this thing up by the numbers and see what it rides like.
In a perfect world...I'de have everything perfect/ spot on. Such isn't the case. As far as the critical dimensions / points are concerned, they'll be perfect, to the best of my abilities.

I have heard of the off set swingarm / rear wheel theory on circle track racers and this makes sence. When I raced the Wisota Modified series, we would not only stagger spring and dampening aspects but also tire size and air pressure for each wheel. These would all change as track conditions tacked up. The best example (most extreme) were the Sprint series cars. They're rear wheel stager is measured in inches! :shock:

I'm 6'5" and weigh 240lbs. There are no metric bikes that fit me well (I'll make an exception for the V-max) and I just plain LOVE my 650, but I wan't a shaft drive, "long framed", metric twin that is air cooled. All the controls will be moved forward, the drag bars are already on for mock purposes, and there will be about a 12"-13" lengthen after all is taken into account; ie. swingarm, rake, and frame stretch. This project has already taken ten times too long but the complications (as Brian mentioned) with "moving things" on a shafty, is not for the faint of heart.

With a 15" rear and a 21" front (40-spokes...again for the look) the bike will drop about 2 1/2" from it's stock set up. I'm still not sure of the mono shock set up. I may go conventional...things will play out in time.

Finding production parts that will convert has taken the most time. Though I am surprised at the number of parts that are interchangeable, with a little effort. Don't hold your breath, I'm going on year #5 with this beast, though now, I've aquired almost everything needed to make the conversions. Time will tell.........(look at my signature) :?

[Dave8338]

Here is just one bike that I think has been done quite well. Though mine will be on a slightly "leaner" diet.

http://www.visiondesign.gr/?p=productsMore&iProduct=53&sName=YAMAHA-VIRAGO-11OO

[Dave8338]

an update...

Opened one present a little early and took some photos...



You can see here, where the "drop" is comming into play. With the 21" front wheel, I'll gain some of that back. Also, the front exhaust is mocked up and you can see where the new rear swing arm is going to need some reworking...I want the bottom edge of the bike to align with the front exhaust...it will be a two into one setup, ending just in front of the rear axle. Also, you can see the need for the frame stretch behind the rear motor mount, to make room for the rear exhaust to exit to the right side of the bike, instead of through the frame, like it was from the factory.



Here you can see the added rake to the neck...16 degrees to give the front end a little more of a "layed down" look and also to drop the whole thing about 2 inches.


If you look to the lower right corner of the photo, you'll see how the new swing arm aligns with the rest of the bike, 3/4" to the right of the center line.


A profile of the project with the new swing arm and wheel mocked up to give me an idea of what things are going to look like... if you look closely, you'll see the new intake that I made to have a two into one carb setup and scrap the original twin carbs...there is a better torque curve with a single carb setup, though I'll loose a little horsepower, that will be adjusted for when the thing is up and running again (920 big bore kit to 1176)