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[FlipOW]

Hi there, since I bought my 2020 SR/S (COV, 47km on the ODO), I am experiencing quite some belt groan. The belt is cleary not aligned as is should be (the famous 1mm gap), but despite multiple attempts, I am not able to find 'the sweet spot'. The belt is rubbing against the flange any time and when I loosen the disc side adjuster only 1/16, it moves to the inner side extremely quick. Whatever adjustments I do (1mm from the flange, 2mm from the flange, 3mm from the flange, 1/16turn, 1/4turn..), after tightning the axle nut from whatever position, it immediatly hits the flange again (I am aware that the belt moves a bit outside when tightning). No sensitivity at all. 

The procedure I am following:
1. loosening the 27mm axle bolt
2. adjust the belt side tensioner to reach the right belt tension
3. using the disc side tensioner to achieve the right position/aligment of the belt
4. Fasten the 27mm axle bolt at 102nm

I have been through several topics regarding belt alignment on the forum, but didn't found the answer yet.. So any recommandations? Ofcourse the dealer is looking at it at well. But that's a 2 hour drive so if there are any possibilities I can do myself, that might save some time.. Belt tension is fine by the way, 62>65hz.

Other question: how problematic is it to drive with some belt groan (only noticable at low speed acceleration)?

[NervEasy]

A bit of belt groan is ok. The fact that you cannot get your belt positiioned right is strange as your described steps of operations is correct...

If the new belt is still a bit greasy from the factory it can enhance groan.

[ESokoloff]

Here are my belt notes for my 2016 DSR with the narrower belt & the previous generations hardware/setup so take that into consideration. 


2016 DSR (thin belt) 20/30kg tension  (using Krikit belt tension gauge).

Jacking left screw(bolt) out (adding tension) moves the belt to the right on the rear sheave/sprocket.
Jacking right screw(bolt) out moves the belt to the left. 

NOTE: Position belt with a right side bias as it will shift to the left when the axle bolt is tightened.
This movement to the left is approx 1/16”-1/8” on my bike (yours might vary).

After making an adjustment to a jack screw, must pry right side of wheel forward (or smack it to the right from the back side) to “set” the adjustment as the belt tension on the sheave will pivot the axle ClockWise...........
(In my opinion, the right jack screw SHOULD be located 180° &  push the axle CCW thus countering the Left jack screw CW effect on the Sheave/Belt/Axle. )



NOTE: 1/6 turn of Left jack screw causes a 10KG difference to belt tension.

Best to get the belt/sheave alignment sorted first, then go for proper tension.
I shoot for the greatest tension (30kg).

If you don’t have the correct Metric socket (like me), use a 1-1/16” to tension the axle nut to 102NM (75#’).
Recommend first removing the jack bolts & grinding or filing off the markings so it’s smooth & will not gouge the soft aluminum swing arm.
Put a dab of Anti-seize or heavy grease on the jack bolt threads while your at it.

A few other thoughts.....

Excessive belt tension is not good on bearings & the thicker belt has a higher tension spec then the thin one.
I’m not sure where the best tension point would be on the thick belt, but I would stay towards the lower end yielding about the same as the max thin belt (30kg) unless the bearings were upgraded & can withstand greater belt tension. 

I use a mechanical tension checking device (Gates 91107 Belt Tension Tester) https://www.amazon.com/dp/B000MUTAGS/ref=cm_sw_r_cp_api_glc_fabc_23M6C0PXQW8W3RV5GE9W and check several locations of the rear sheave/sprocket in case it’s slightly out of round (different run outs will yield different belt tension readings).

A hexagon fastener has 6 sides so one flat (1/6 full turn) of the LEFT bolt will yield a 10kg change in belt tension.

Must make sure there is a gap (credit card or greater) between the belt & the left hand lip on the sheave/sprocket).

[FlipOW]

Here are my belt notes for my 2016 DSR with the narrower belt & the previous generations hardware/setup so take that into consideration.

[…]

Must make sure there is a gap (credit card or greater) between the belt & the left hand lip on the sheave/sprocket).

Thanks for the notes! I came across your notes in other threads as well and I was familiar with the procedure on the Gen2 bikes. I used to have Gen2 Zero’s before, and I adjusted belt tension and alignment multiple times at those bikes. Without any problems. So the fact that I cant get it right on the SR/S makes me therefor a bit irritated as well 

[ESokoloff]

In your original post you state that you are tensioning the belt & then attempting to align. 
I found that I must align & then tension.   
That’s what I would suggest you do. 




I’ve never worked on a next generation bike so I’m not guarantee this will work but it’s seems logical to me…….

Start off with the belt flush on the right side of sheave & then attempt to move wheel CCW (as viewed from above) [I presume belt is on left side].
Tighten wheel nut to proper tension & see where belt ends up.
If not acceptable, repeat procedure but move belt where it needs to be in order to have it end in the exceptable location.
Then adjust both jack screws equally in or out to achieve proper tension.