ST1100 swing arm re assembly

[drawderm]

Ive had the swing arm off to paint and now its ready to go back on. The manual I have advises to install swing arm in frame with bearings and ito then insert right and left bearing bolts for want of a better word, then tighten the one on the right to the specified torque before doing up the left side and then finally putting on lockong nut and chdcking movement etc.

My question however is depending on how you place the swingarm to begin with, it could be a little bit more to the left or to the right but still have the correct torque applied.

How do I know where the swing arm should fit in relation to left / right and is therefore correctly alligned and following the front wheel?

 

[John OoSTerhuis]

The pivot bolts align the swingarm correctly… fixed points on the frame. The right one is torqued tight/fixed and the left one is where the bearings preload is set.

 

[drawderm]

Yes, but i am speaking about the transverse postion of the swing centred in the frame or not as the case may be. Whats to stop me screwing in the right bolt 25 turns and the left bold 20 turns and then torquing both correctly OR screwing in the right bolt 20 turns and the left Bolt 25 turns and then torquing correctly etc.

Doesn't this mean that the swing arm is going to be a little different in the first scenario then it would be in the second scenario? Ie. It is going to be a little further to the right or the left even though both bolts are torqued correctly and in the correct sequence?

 

[John OoSTerhuis]

If you took off the swingarm you may have noticed the right pivot bolt bottoms in the frame. IOW can only go so far in/left. The high torque is to insure it doesn’t back out and reduce the bearings’ preload. The lock ring on the left pivot bolt insures it doesn’t/maintains the preload.
Check the right pivot bolt recess in the frame, confirm, and report back. Please.
John

 

[drawderm]

If you took off the swingarm you may have noticed the right pivot bolt bottoms in the frame. IOW can only go so far in/left. The high torque is to insure it doesn’t back out and reduce the bearings’ preload. The lock ring on the left pivot bolt insures it doesn’t/maintains the preload.
Check the right pivot bolt recess in the frame, confirm, and report back. Please.
John

Hi, a few pennies have dropped since yr first reply. I have since tightened up the right side, (brake side) to 105nm, then tightened up the left to 22nm, then lock nut at 105nm.

Thanks for yr help. I understand now - not sure what i was thinking off

 

[STRider]

If you took off the swingarm you may have noticed the right pivot bolt bottoms in the frame. IOW can only go so far in/left. The high torque is to insure it doesn’t back out and reduce the bearings’ preload. The lock ring on the left pivot bolt insures it doesn’t/maintains the preload.
Check the right pivot bolt recess in the frame, confirm, and report back. Please.
John

Need to talk to @Mellow about enabling a 'double thumbs up' for posts like this @John OoSTerhuis

 

[jfheath]

Excellent stuff.

It is extremely important that the exact torques are applied to both the bearing and to the locknut - and that the bolt is held completely still while the locknut is torqued. And for that, you must use the special tool.

Story time to qualify that last statement.

In my youth I did a lot of cycling and building / rebuilding pushbikes. One skill was getting the wheel bearings adjusted properly - loose ball bearings and a conical 'nut' which was scooped to form the outer race for the bearing as well as keeping them in place. Tighten this too much and the bearing is would be stiff to turn. Tighten it too little and the wheel would spin freely, but it would have a lot of play and would wobble on its axle.
The margin between these two states was tiny. I wanted zero 'play' but a freely spinning wheel. Finger tight and then back it off a smidgeon was just about spot on.
Then hold the cone in place with one very thin cone spanner, and tighten the locknut with the other - holding the axle solid at the other end. Perfect. Except it didn't work. Every time the lock nut was tightened, it introduced 'play' in the bearing.

So start again.

The issue is that the tightening the locknut, doesn't just clamp the locknut down onto the cone, it also 'stretches' the axle - by that, I mean the correct pressure on the bearings has been altered by the threads of the nut and bolt being squeezed more tightly together - The locknut was pulling the cone towards it - only a tiny amount but enough to make a big difference, which could be felt as extra play in the wheel bearings.

So the technique had to be changed. Tighten the cone finger tight - and then a tiny bit more with the spanner to compensate for the 'stretching' effect. Then tighten the locknut. Then test. Repeat until the required feel was obtained. Eventually I got to know know how much 'tiny bit more' had to be applied and I could get the bearing spot on almost first time every time.

The same thing applies to the swing arm bearings. They are tapered bearings, so as you tighten, the bearings are pressed into their shell and will not be able to move. Just like the pushbike cone. Put on the locknut, it doesn't just tighten the locknut, it relieves the extra pressure on the roller bearings.

Honda have worked out how much 'that tiny bit more' is - so when you tighten the left hand bearing bolt, they specify a torque setting that is actually too tight. Then when you tighten the lock nut it is exactly the right amount to keep the locknut tight AND to relieve the excess pressure on the tapered roller bearings.

It is extremely important that the exact torques are applied to both the bearing and to the locknut - and that the bolt is held completely still while the locknut is torqued. And for that, you must use the special tool. The amount of torque quoted for the locknut has been adjusted to correct for the added leverage of locknut tool's arm.