Venture and Vmax Swingarm comparison?

great white · Nov 3, 2015

The driveshaft looked to be a no go with the 17 incher mocked up. Just not enough clearance to get it plated back up. It only looked to be 1/16" from the rubber and that was with the tube still cut open.

So I decided to stop half arsing it and stripped the complete rear off the bike right up to the rear exhaust pipes.

Then I dropped plumb lines to the floor to lay out the actual bike center-line instead of assuming that the rear subframe was straight and symmetrical.

I dropped a plumb line from the steering neck and one from the swingarm frame mount pad center. Then struck a line between the two and extended it out the rear (string line).

Now I had the dead center of the bike (at least as far as the wheels/frame were concerned).

Slide the rear tire and swingarm back on and it looks like I'm going to have to accept about 4-4.5 mm off center-line to get enough clearance for tire and driveshaft once the notch is welded back up.

I wanted dead center but 4 mm is pretty close. Hopefully close enough that there should be no noticeable handling effects as I want this bike to be a "handler" as well as a "goer".

There are a lot of OEM bikes out there running around with a lot more than 4mm offset.....and way more than a couple modified bikes....

great white · Nov 4, 2015

Well, plated the swingarm notch back up.

I left myself 0.32" (roughly 1/8) clearance inside the tube for the driveshaft (wrapped it in 32 thou lock wire) and I have 1/8 between the tire and swing arm.

Even at that, my rear wheel offset from centreline is 7mm.

i'll have to just live with that as there's just no more room to wiggle it lower. Without getting too close on tire, rim and driveshaft.

I guess the early ventures are tighter than the vmax. I have no idea why though, the output drive on the engine is in the same place. Maybe the frame is a touch narrower?

Dunno.....

one2dmax · Nov 4, 2015

Yea, that's well more then you need if you did .320 (which is 5/16" approx). If you did .032" then it's close but should still work. 1/8" is .125" by the way.

Sean

great white · Nov 4, 2015

one2dmax said:
Yea, that's well more then you need if you did .320 (which is 5/16" approx). If you did .032" then it's close but should still work. 1/8" is .125" by the way.

Sean

Yup, don't know what I was thinking with those numbers. Must have had a bad math moment converting back and forth between decimal, fraction and metric.

Shaft clearance ended up at a measured .053, which is aroun 1/19. Not quite 1/16, but close.

Tire clearance is 1/8, don't really want to get closer than that due to tire differences between manufacturers.

The rim clearance is a about 1/16, but that's at a spot where I can easily cut a bump in the tube off and plate it flat.

Final positioning makes the offset at 8-9 mm.

As long as the frame and swingarm are straight, it should (hopefully) be fine.

It is a touring bike after all. I just like to hustle through twisty sections too. It used to be fine, hopefully I haven't messed that up but made it better.

I plan to through the Oem wheel on there and measure that to see if it also had an offset. Should give me a good idea of how "out" it actually is from stock.

great white · Nov 5, 2015

1986 swingarm, 1986 VMax diff, 1983 oem rim/tire, measured offset from same ref point as the 170/60 17 combo: 3mm

So I've added 5-6 mm to what could be considered the "oem offset".