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[ZeroChrissy]

I have the plan to replace my front sprocket at 2017 SR.
(seems, one of the side lips is damaged by some dirt!? tooth version, not the keyed version)

Hopefully, there is enough clearance by only removing the swing arm!?

Does somebody knows the torque for the pulley screw? Loctite or not?

Very best Thanks for any help.

[Gains]

I think you have to take out your motor. The sprocket is fixed with loctite, so you better heat it up to melt the loctite. Do not use a hammer, because you might ruin the adjusment of the position sensor on the other end of the shaft. I think there is info about this in the unofficial maintenance manual

[ZeroChrissy]

Yes, I will not use a hammer...

But in best case, I will try to keep the motor in...
Think, I can try to loosen the screw. If that is possible, I think I can remove the Pulley with a puller.
Should all work through the hole of the swingarm bearing... in theory :-)

[Biff]

Do you have any photos of the damage to the sprocket?
-ryan

[GoneToPlaid]

I changed from belt drive to chain on my DSR, and when I did I torqued the front pulley bolt to 50 ft-lbs.  I was never able to find an official spec for that bolt.  I also used Loctite 242 (blue / medium).

I used a propane torch to loosen the original threadlocker, which was both on the bolt, and also between the pulley and shaft splines.  That pulley did NOT want to come off until after I heated it.

[Auriga]

For future reference, here is Zero's official torque for the two sprockets on a wide belt sds/xmx bike.
Motor Shaft Sprocket Bolt*   71 N•m   52 lb ft
Rear Sprocket Bolt*   35 N•m   26 lb ft

This is the same for the thin belt bikes, with the addition of the set screw:
Motor Shaft Sprocket Set Screws   2 N•m   18 lb in

So you were pretty much spot on.

[ZeroChrissy]

Thanks a lot...
70Nm seems plausible for a M10/10.9 screw. But that torque is very high for an HX6 allan key. Not sure if my PROXXON tool can handle that. So, first I will order a HAZET 986SLG-6. (But always better to damage the tool, as damaging the screw :-))

I think Loctite arround the shaft makes only sense with the "keyed" version of the pulley. It have the pulley with the "teeth" arround the shaft, from 2017 on. Hopefully without Loctite. If so, it would make no sense for me.

Think a "impact screwdriver" is also not a good option cause of the encoder magnet,- rotor magnets, right?

Will see...

[Biff]

Thanks a lot...
70Nm seems plausible for a M10/10.9 screw. But that torque is very high for an HX6 allan key. Not sure if my PROXXON tool can handle that. So, first I will order a HAZET 986SLG-6. (But always better to damage the tool, as damaging the screw :-))

I think Loctite arround the shaft makes only sense with the "keyed" version of the pulley. It have the pulley with the "teeth" arround the shaft, from 2017 on. Hopefully without Loctite. If so, it would make no sense for me.

Think a "impact screwdriver" is also not a good option cause of the encoder magnet,- rotor magnets, right?

Will see...

The pulley with the teeth (splined shaft) is glued on , it will require fire application along with a gear or bearing pulling tool to remove without damaging the motor.

Are you able to share a photo of the damage to the motor pulley?

-ryan

[ZeroChrissy]

I can share a picture after removing the belt...

Uuuups, Loctite between the theeth?
Sounds surprising now after watching that... ~6:40min
https://zeromanual.com/wiki/Chain_Kit


?
Will see, what's inside my zero surprise egg :-)

[ZeroChrissy]

All done...
New pulley is in, without removing the motor.

In general, it was more easy than thought.
Only at the screw itself was Loctite. (Used a heatgun so warm up, only the screw)

With a selfmade puller it was easy to remove the pulley, no Loctite at the teeth.
(It's only a little hard in the beginning.)

There was exactly the clearance, to get the pulley out. Thanks Zero!

Bigger pain was to replace the left crispy swingarm bearing. (I think, that's only possible with removed pully, so it did that, too)

[Dr Bob]

While replacing the motor bearings, I broke off a 6mm hex key in the shaft screw head. Jammed flush and the hex looked chewed.
So I spark eroded an 8mm hex hole using a tap burner and 5/16 inch hex brass bar.
Here is a video of the setup.