Alternate tire size?

[GuzziMoto]

10 minutes ago, LaGrasta said:

Hey guys, since I removed the rear wheel, I also removed the jack-shaft for proper lubing, successfully completed. To do so, I removed the swing arm pivot dowels. What is the realignment process, I cannot find it in the factory manual.

Uh, is it too late to say "set them back to the same depths they were at before you removed the rear swing arm?

[docc]

3 hours ago, LaGrasta said:

Hey guys, since I removed the rear wheel, I also removed the jack-shaft for proper lubing, successfully completed. To do so, I removed the swing arm pivot dowels. What is the realignment process, I cannot find it in the factory manual.

At one South'n SpineRaid we measured the "standoff" of the threaded part of the pivot pins on six or eight spine frames. I had already taken great pains to set mine to center my tire contact patches to one another using a laser.

The conclusion came down to : turn each pivot in equally until they bottom, then back each off very slightly to unload the inner bearing races.

[LaGrasta]

…will do just that, thank you @docc

[Lucky Phil]

5 hours ago, docc said:

At one South'n SpineRaid we measured the "standoff" of the threaded part of the pivot pins on six or eight spine frames. I had already taken great pains to set mine to center my tire contact patches to one another using a laser.

The conclusion came down to : turn each pivot in equally until they bottom, then back each off very slightly to unload the inner bearing races.

I don't back them off docc, too much chance of introducing freeplay. All single/double groove ball bearings will accept a decent amount of axial load and commonly do in practice. It's when it becomes excessive it's an issue such as when the wheel bearing spacer is too short and the amount of torque applied by the axle nut has to be tolerated. Remember even in that case the wheel bearings still last quite a while. In the case of the massive double row ball bearings at the pivot a small amount of preload is preferable to zero or clearance. When I say small I mean "nipped up" to coin an Aussie phrase. Maybe 1 foot pound or so. Think about ball races in a car gearbox main shaft and layshaft for example restraining the lateral force imposed by helical cut gears and 5 or 6 hundred foot pounds of torque generated by the engine. 

The Koyo bearing catalogue also backs this up for deep groove ball bearings and advises if axial loads are large to increase the shoulder radial depth in the housing. So they accept that significant axial loads will sometimes occur.

Phil

 

[docc]

13 minutes ago, Lucky Phil said:

I don't back them off docc, too much chance of introducing freeplay. All single/double groove ball bearings will accept a decent amount of axial load and commonly do in practice. It's when it becomes excessive it's an issue such as when the wheel bearing spacer is too short and the amount of torque applied by the axle nut has to be tolerated. Remember even in that case the wheel bearings still last quite a while. In the case of the massive double row ball bearings at the pivot a small amount of preload is preferable to zero or clearance. When I say small I mean "nipped up" to coin an Aussie phrase. Maybe 1 foot pound or so. Think about ball races in a car gearbox main shaft and layshaft for example restraining the lateral force imposed by helical cut gears and 5 or 6 hundred foot pounds of torque generated by the engine. 

The Koyo bearing catalogue also backs this up for deep groove ball bearings and advises if axial loads are large to increase the shoulder radial depth in the housing. So they accept that significant axial loads will sometimes occur.

Phil

 

"deep groove ball bearings" . . . is that the "C3" specification?

[Lucky Phil]

7 minutes ago, docc said:

"deep groove ball bearings" . . . is that the "C3" specification?

No docc C3 just refers to the bearings internal clearance. The V11 wheel bearings are the classic single row deep groove ball bearing as an example.

Phil

 

[LaGrasta]

So evenly inserted, lightly tight, very lightly.

[LaGrasta]

I'm still waiting for my tires to arrive, but last night I seated each dowel; it was fairly straight forward.

I measured each to assure same starting threads, then clockwise rotated each evenly, one side then the other; back and forth, back and forth. When one eventually seated, I backed it off one full turn, and matched the other. As it sits now, one side is one full rotation from seated, and the other is a little less than one full rotation. It seems to me, there is a bit of acceptable variance, and I should be well within.

Once I mount the tires, I'll bounce it a bit and see what it looks like, listen for any concerns. Hopefully, that should do it.

Thanks for the advice.

[docc]

Backed off a full rotation seems like a lot to me, but I'm no expert.

[audiomick]

I also reckon that's probably too much. Sure, it is a fine pitch thread, but still.

 

[LaGrasta]

As they are not 100% even, Id say I still have a full turn on one side, and only 3/4 on the other.

I can dial it in a wee bit more, what do you suggest?

[docc]

Bring them in so they are the same both sides to where they just touch, as Phil suggested?

IIRC, it was @gstallons that suggested backing them off a touch. I got the impression of a thousandth of an inch or two.  Perhaps he could repost that rationale.

[GuzziMoto]

I would treat it like other bearings you set, tighten it so it is tight, but not so tight it cause it to bind or drag. The swing arm should still move easily, but it should be as tight as it can be and still allow the swing arm to freely move. But I am no expert.

[gstallons]

AFA all the prefix and suffix characters of bearings you will have to Google or look in a bearing manual to interpret the information. All that stuff has a reason so use all of this when purchasing replacement bearings. 

 You do want the rear wheel tracking in the center of the path of the front wheel . I rigged up a contraption of two florescent lamp bulbs to show where the rear wheel is located in relation to the front. Use the center stand to keep the bike the bike upright and place the front wheel straight ahead . Make your adjustments to get the rear wheel in the center of tracking . When you get your alignment finished , tighten one adjustment screw to about 30 lbs to seat , back off and get it just snug (hand tight) then  tighten the adjusting nut.

[docc]

After your alignment, @gstallons, how much difference is there between the two pivot pins? 
 

(Using my laser method, I found a difference of 0.002" and put this down to the tolerances of the method.)