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[KuRi]

Hi!

Today I was doing some periodic maintenance on my dsr 2020 and noticed the belt was a little loose. So I just adjusted it to correct tension.

After that, I was tightening the rear axle nut as usual with my torque wrench to 73.5 lb/ft as stated in the manual (I have done this several times during this year when I was learning to adjust the belt tension), but this time I had to tighten more than usual. What I mean is that the white mark that Zero puts on the nut is now not aligned with the mark on the axle and it has gone 1/8 or 1/16 of more turn than usual to reach the required torque. I know that's a very small difference but it never happened before.

Is this normal? Any problem? I have tried loosening and tightening again a couple of times and it always reaches the same spot now.

thanks!

[TheRan]

I wouldn't worry about it, it's a very small difference and tightening torque on most stationary components doesn't need to be 100% accurate. There are a few things that could have caused it to reach that torque value sooner previously like dirt in the threads or on the contact surfaces or a burr on the threads of the axle or nut, or there could be something that made it reach the torque value later this time such as some stray lubricant on any of the aforementioned locations.

[TNCreator]

I would not worry either, many of the screws on my SR were a bit re-tightened after factory according to the white marks.

[KuRi]

Thanks for your answers, very much appreciated.

I just went for a ride and everything is smooth and running fine. Adjusting belt is the best thing I have learnt this year xD

[rogerpiano]

The same thing happened to me too.

I just adjusted the belt tension and when I tightened the rear axle nut with the torque wrench to 102 Nm the two white marks no longer aligned.

I also tried to increase the torque of the wrench (considering the 4% tolerance) but I realized that, even reaching 110 Nm, the nut does not tighten anymore.

It would be interesting to see if this happened to someone else

[KuRi]

I can see that in your case you were not able to reach the same spot. In my case it was the opposite, to reach the 102Nm I had to go beyond the mark...

I have read in a lot of places that it does depend on the other components (wheel, adjuster, abs, ...) and that is not a problem as long as the difference is not too big, and yours and mine are really small.

[TheRan]

If the nut isn't tightening as far as it used to at the same torque then one cause could be dirt on the threads or the mating surface of the nut, but as it doesn't turn any further with increased torque that's probably not the case. As you moved the wheel forward or back it could be that that section of the swingarm, where the adjuster blocks sit inside the slot, is thicker than where it was previously.

It's an M20x1.5 nut so that means one full revolution is 1.5mm. From flat to flat of the nut is 60° and flat to point is 30°, you nut looks to be counter-rotated by even less than that so I'd guess around 20°. That's 1/18 of a full revolution which means the thickness would only need to be increased by 0.08mm which seems entirely plausible to me.

[rogerpiano]

As you moved the wheel forward or back it could be that that section of the swingarm, where the adjuster blocks sit inside the slot, is thicker than where it was previously.

I think that's right. In support of this thesis I add that, in KuRi's photo, we see that the vertical alignment notch is located between the third and fourth notch (let's say at 3.75) while in my case it is exactly on the fourth notch (therefore at 4.00).
So the KuRi wheel should be further back than mine and that means as the wheel moves forward, 102 Nm is reached earlier

[KuRi]

Yeah, but don't take the alignment notches very serious, they are often not very precise as they depend on other adjustments and manufacturing imperfections

It was closer to the 4th notch when I received the bike, but the tension was below 25KG, so I had to move it a little to reach a value around 35-40kg.