Chain Tension Adjuster keep BENDING!!!

[bulletproofcycle]

I switched to a 15 tooth sprocket.

I tightened the axel bolt as per the manual.

I ride the bike pretty hard, I did a few burnouts and a few clutch wheelies which puts a lot of stress on the adjuster since it like all the force at once.

I can't seem to keep the left adjuster from bending which screws up my alignment and chain tension!

I usually toque the bolt to 58 ft lbs.

I noticed if I torque it to 73 ft lbs it no longer moves and fixes the bending but I am worried if this will screw up the bearings by putting too much stress on them.

Thanks

[runsilent]

Chiltons says 36-58 ft-lb, 73 ft-lb isn't that much more.  Besides, the additional torque will not add additional preload to your rear brgs. 

The axle nut tightens thru the inner brg races and the spacer between them.  Brg preload is determined by the difference between the spacer length and the c'bores in the hub where the outer races seat.  After torqueing to the min figure, additional torque will not increase the brg preload.

[JamesG]

Burnout, wheelies, and other silliness doesn't put that much stress on the plates if you have the axle torqued correctly.

Are you talking about the adjuster or the flat swingarm end plate it threads into?

Are you beating out flat and reusing the bent adjuster plate?
If so it may be metal fatigued and weak now.

Also, and no offense, you are loosening the axle before adjusting the chain tension right?

If the rear axle/bearings/spacers are assembled correctly no stress is put on the bearings unless you put a truely stupid amount of torque and crush them (but I think the swingarm would give first).

[brett]

I'm not sure if this is the answer, but did you replace the cotter pin in the axle nut? I've found that this comes loose when I'm riding hard if I don't replace the cotter pin after adjusting.

[pantablo]

I talked to Leo at the track and he had the same problem with his, without any hard riding or stunts, with the axle torqued properly (I think). I haven't ever heard of this problem to the extent it comes up recently until the F model came out. I think the adjuster plates are inferior to the older plates.

You can try doubling them up or creating your own from 3/16" steel plate.

[EDub]

what about getting an extra set and doubling them up.... or heat treating them.... with a blow torch then quenching them in water.. making them more rigid? 

[sledge]

You really cant expect the bike and its component parts to be reliable if you make modifications that cause extra stress and by riding it to the limit constantly. Firstly I would be checking the torque wrench, it doesnt take much for them to go out of calibration particularly if left unused and set at the top of the scale. It could well be clicking out at a lower figure than its indicating. Next I would taking the axle-bolt out and carefully examining the threads, same with the nut, if they have stretched this will be making the nut tighter on the threads causing an inaccurate torque figure. I would also junk the split-pin/castle-nut arrangement in favour of a self-locking nut (Nyloc). They are in my view much more reliable and capable of handling a higher torque figure. This is stated in the Suzuki service manual and its the standard way here in the UK, dunno why you guys get the split-pin.....must be some regulation or standard I guess. Taking the nut past the reccomended figure wont help the situation, in fact it may well weaken the bolt. The clamping effect of the swingarm legs when the axle-bolt is tightened does little to hold the wheel in place when under hard acceleration, its the plates which absorb the stress and dissipate it lateraly down the swingarm legs preventing the wheel from being dragged forward by the chain. In your case the stress has been increased by the smaller sprocket and constant stunting and as a result the plates are distorting. If you are going to carry on stunting I would  be considering stronger adjuster plates, I would have them made to sample size from 6mm stainless- steel plate with relived edges on one face to accomodate the end of the swingarm. No way will they distort and they will look pretty good too. I would also change the original adjusters, if the threads have been subject to enough stress to bend the plates, chances are the threads have been stretched and therefore will have been seriously weakened. It wouldnt be a bad thing at the same time to modify the new adjusters by taking the original threaded section out and replacing it with the next size up with resulting in an increase in strength and again using nyloc nuts. I appreciate you may not be able to carry out the work yourself but its nothing to a small Engineering firm, just show them the parts, explain what you want and get a price.