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[awgmat]

Hi Team,

I'm on my second FXS 2020 model, after my first (also 2020) was a write-off after an accident.

The second FXS has always been much noisier than the first, and I'm wondering if the belt is misaligned or too tight.

What do you pros think? Video link to the noise below:

[lunarx]

Nice that you got another FXS 

Assuming you checked Belt-Tension via the Gates "Carbon-Drive" App?

Have you listened to it, with the Belt-Guard removed?
While it's removed, use this to check the Belt alignment.
https://www.motionpro.com/product/08-0048

[Shadow]

Align it with the rear axle nut hand-tight so there's a hairline gap between the belt edge and the sprocket guide wall and then torque the rear axle nut to spec; if I recall correctly, like it was on the S/DS, the FX will also nudge towards the center-line of the sprocket when the rear axle nut is tightened. Tension should be loosened periodically when the belt is new at say 500 miles and 5000 miles since the outer diameter of the belt stretches out less than the swelling of the inner working surface materials (effectively making the belt tighter tension over time).

[Red Clay]

Question: Is the belt centered on the front sprocket? This is done by adjusting the motor mounts. To move the belt left on the front sprocket: loosen the two right rear motor mount bolts, turn the big silver adjusters in slightly (1/4 turn), retighten the bolts. Check it and repeat if needed. After tightening the back twice, consider next extending the two right front adjusters (slighty). Visa versa to move the belt to the right on the front sprocket, BUT, don't extend the two right rear adjusters too far or the motor mount will conflict with the swingarm. This truly makes the motorcycle run smoother and more quietly. Hope this helps.

Ride On, Red Clay

[awgmat]

Hi All - thank you so much for your useful suggestions.

lunarx - I have a krikit for the belt tension. It was coming up at 65+, but now I've reduced that down to c. 45. I checked the alignment whilst doing that an adjusted. It looks straight now, but the belt still has a tendancy to wander over to the raised lip edge of the rear sprocket (even though I was doing what Shadow suggested when tightening the rear axle bolt) - is this normal? Can I do anything to keep the belt centred on the rear sprocket? I suppose it is still very slightly out of alignment.

Shadow - thank you for your tip, but I'm still stuggling to get perfect alignment. I suppose if the sprocket is moving slightly to the right when tightening, it may be throwing it slightly out of alignment, even after getting the belt alignment spot on when the nut is just slightly loose? I might try again...

Red Clay - really interesting comment. I'll have to have a closer look. When I've glanced at it (albeit there is not a perfect view of it without disassembling elements around it) it did seem to be centred, but I'll check again for sure!

[ESokoloff]

Align it with the rear axle nut hand-tight so there's a hairline gap between the belt edge and the sprocket guide wall and then torque the rear axle nut to spec; if I recall correctly, like it was on the S/DS, the FX will also nudge towards the center-line of the sprocket when the rear axle nut is tightened. ..... 

On my 2016 DSR (viewed from behind) I found that the belt travels left towards the sheave (sprocket) lip upon tightening so start out with the belt on the right side edge.

Here are my notes on belt adjustments (2016/thin belt).



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.

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.

[ESokoloff]

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).