Yamaha TRX850 Enthusiasts Forum

Hi,
I have a question about the tension bar connected to the swingarm and the rear caliper. How come it is locked on both sides at 30Nm though it is supposed to move according to the rear axle ? I cannot make a tension of my chain because it would not move. I read nothing about it in the service manual so i am very much surprised. Shall I unscrew these screws each time i make a chain tension???
Thanx !

I thought it is standard practice on any bike to free off the torque arm if it is bolted in place? Tighten chain, tighten axle, tighten torque arm..

Although with the lovely aluminium arm on the TRX you'll probably find that you have to undo the nuts and then break the fuk'r free from its corrosion at the swingarm mount

Oh crap. I didnt touch the thing when ive tensioned my chain. Didnt have a problem sliding the axle where i wanted it though ,, was a bit sticky come to think of it but didnt seem to be a problem.
Am i doing it wrong?

When the rear wheel axle is loosened to adjust the chain the calliper mounting bracket then pivots around the axle keeping it aligned with the disc. There is no requirement to remove the torque arm as it pivots up and down as the calliper moves forward/backwards..

Snod Blatter wrote: Although with the lovely aluminium arm on the TRX you'll probably find that you have to undo the nuts and then break the fuk'r free from its corrosion at the swingarm mount

Yep, my guess is that the calliper mounting bracket is locked onto the axle etc with corrosion, if it don't want to move then pull it apart and fix the issue

Nice one, cheers!

Thank you all for your answers, and especially rod.s picture !
I think we have found the problem : not corrosion but probably previous owners (mechanics?) who tightened with too much torque the bolts on the swingarm and the caliper bracket, and then who deformed the aluminium tension bar "forks" on both sides. Now the caliper bracket cannot move freely even when I put the advised 30Nm torque.

Why would you expect it to move freely once you've tightened the bolts to hold it in place? Am I missing something here

Tightening the bolt/nut at the end of the tension bar to the correct torque ensures that the bolt/nut is firmly seated to the bar, but no so much that the forked end of the bar deforms and seizes the caliper mount or swing-arm lug.
Over-tightening will deform the forked end and lock everything solid.
I had written this out in more detail a couple of days ago but somehow forget to actually post it up. Sorry.
You may be able to gently pry the forked ends apart so that the caliper mount can slide in and out freely, then torque the bolt correctly and see if it still allows some rotation.