VintageVmax.com

I installed a 1 3/16 inch lug track on my 1986 VMAX tonight.

By using 8 tooth drivers, I am seeing about an inch of clearance around the track where it goes around the front drivers. This appears to be adequate.

The upper rear wheels that hold the track off the top of the rear shock holds the track high enough for the lugs to touch the tunnel coolers. It is not enough to keep the track from turning by hand, but it puts shiny spots on the tips of some of the lugs. If I put smaller wheels on that axle, the inside of the track would rub on the top of the rear shock.

I think I need to drop the rear suspension attachment holes. The question is how much do I need lower the hole. The problem is the existing hole is centered ~30 mm from the footboard and has a 30 mm diameter washer. The bolt is 10 mm diameter therefore if I drill the hole as low as possible using the existing washer, there will be only 5 mm of metal between the two holes causing an apparent weak spot.

Is 5 mm of metal enough?
Should I put a flat spot on the washer to drop the hole another 5 mm so there will be 10 mm of metal between the holes?
Should I put a tab below the footboard?
How much can I drop the rear attachment hole before I need to move the front attachment hole proportionally?

What I have done in the past was to notch or trim down the lugs that touch.

Also by going to 8 tooth drivers your gearing will be all screwed up,you will be geared realy low.

The original gearing was too tall for my riding conditions resulting in short belt life and the outer part of the drive clutch seldom (if ever) getting used.

There is not enough clearance in the tunnel to get the drive axle installed if the 9 tooth drivers are used.

The down side of the 8 tooth drivers is the speedometer reads about 12% high.

I can adjust the gearing inside the chaincase but not the speedometer calibration.

If the 1 3/16 inch lug track does not work out, I will try to find a 1 inch lug track.

what is the stock lug height? and has anyone tried to get an original style track or close to original with the straight lugs instead of the wavy or nobby types that im seeing lately . i just recently started looking at tracks for my 83.

Stock lug height is 5/8 inch.

OEM track is still available from Yamaha.

thanks joe!

Update...

I trimmed the lugs where they fit around the tunnel coolers. The track fit until I installed the small wheels that hold the track up between the front and rear suspension attachment points. It held the track against the coolers.

I filed the shaft mounting holes down about 5 mm and the track turns by hand with everything installed and tightened.

Is 5 mm of clearance between the track and coolers enough?

If it rains again tomorrow, I might try running it across the field to see how it works.

I think if I were you i would leave that shaft out,I dont have one on mine, many other makes do not use a shaft like that.

My guess was that shaft was to reduce the slap distance in the tunnel.

Does your track slap the top inside the tunnel?

WPS used to sell a relocation bracket for that shaft for the vmax 500-600 when useing a tall lug track check with them and see if it is still available,my sled has an sc10 rear suspension that is why I dont have that shaft, I would think that if you had the proper tension on the track thare shouldnt be much slap.

It rained this afternoon and I took the VMAX out for a ride in the field.

The track did not slap and the drivers did not slip.

There is a slight clicking sound from the front area of track from the time I let off the throttle until I hit the brake at the other end of the field that I don't recognize. It did not occur in the corners, on the throttle or on the brake. It only occured when coasting.

What is the chance it might be track clips hitting something on the slide rail?
What other things might go click?
Driver sprockets?

I'll bet it is the clips hitting the front of rail and you can hear them slapping with out snow to lube ? You may have the track too tight ?

The shop manual says to pull 22 pounds and the deflection should be about an inch.
I set the defection to 1 3/8 inches.

It seemed a little tight to me, but I was trying to follow the manual.

Should I loosen it more?

Here is a photo of the back corner showing the track and carbides.



Note one of the three rows of carbides has been removed.
The top visible row is closely spaced and did not hit anything.
The second row was wide spaced and had to be removed because they hit the coolers.
The third visible row was moderately spaced and did not hit anything.

Three of the usable stud row studs were broken so I replaced them with some I removed from the wide spaced rows.