replacing chainring

[peterk]

My 2020 Stance-e made new crunchy sounds as soon as I put on a new chain. Fearing somehow it was the motor, I put the old chain back on and the noise disappeared. Phew.

The noise is definitely from the front, not the rear derailleur so I guess the chainring is done.

How do I remove the old one? It seems to be held in place by a big nut. Is it just removing this big nut? Is there anything godlike left-hand thread to deal with.

Thanks.

 

[Paul Mac]

What motor is it?

 

[peterk]

Yamaha SyncDrive Sport

 

[peterk]

Does this help?

 

[MinusPrevious]

On our Trances the front Praxis sprocket requires the chain to be properly indexed onto the specific cogs. Your sprocket appears diff than ours but check that the chain doesnt need a proper index

 

[peterk]

By proper indexing do you mean proper shifting from cog to cog? There has been no change in the shifting. Still spot on regardless of new or original chain. I've also made sure that the chain position is right for the narrow-wide ring.

 

[Paul Mac]

Can't help you the Yamaha, I've got a bosch and the locking is a reverse thread.
What the previous poster means by indexing is the chainring has a wide tooth followed by a narrow tooth. This has to fit in the correct chain links. If you look you will see the links have a wide and a narrow link

 

[MinusPrevious]

By proper indexing do you mean proper shifting from cog to cog? There has been no change in the shifting. Still spot on regardless of new or original chain. I've also made sure that the chain position is right for the narrow-wide ring.

See attached image of our Praxis. Just taking a crack at your issue as your ring type may not need this level of detail

Cheers, Joe

 

[peterk]

Can't help you the Yamaha, I've got a bosch and the locking is a reverse thread.
What the previous poster means by indexing is the chainring has a wide tooth followed by a narrow tooth. This has to fit in the correct chain links. If you look you will see the links have a wide and a narrow link

I'm guessing they are all reverse thread.

Yes I made sure the chain matched the ring in terms of narrow-wide.

 

[Mikerb]

You would expect that nut to be reverse thread but usually it would be marked with direction and torque setting............try cleaning it up to see if you spot any markings??

 

[peterk]

KMC Black 10 spd, not "e" specific. From ChainReaction.

With no resistance the chain is very quiet but gets crunchier with more pedal force. When looking at it while pedalling with force it seems to be slow in falling off the chainring almost like it is about to chain suck.

 

[paul-g]

Does this help?

View attachment 55564

is the nut a full nut

 

[paul-g]

Does this help?

View attachment 55564

reason i`m asking this is it looks the same as my full e
i used a hub nut socket 36mm from euro car parts, it was the only socket that
had the length to get round the crank shaft, and it was l/h thread

hope this helps
Laser Hub Nut Socket Thin Walled Deep 36mmProduct Code: LAS6279
check sizes first
(

 

[peterk]

reason i`m asking this is it looks the same as my full e
i used a hub nut socket 36mm from euro car parts, it was the only socket that
had the length to get round the crank shaft, and it was l/h thread
View attachment 55673
hope this helps
(

Yes a regular hexagonal nut and upon further inspection and cleaning, I can see a directional arrow on it for tightening direction. Mystery solved. I'll check to see if it's 36 mm before getting a suitable socket.

Thanks all.

 

[paul-g]

Yes a regular hexagonal nut and upon further inspection and cleaning, I can see a directional arrow on it for tightening direction. Mystery solved. I'll check to see if it's 36 mm before getting a suitable socket.

Thanks all.

if you do get it off instead of buying the whole
spider and chainting together maybe think of
getting a spider to fit and then it leaves your options
open to what chainring you want to use 32t,34t,36t etc

 

[peterk]

if you do get it off instead of buying the whole
spider and chainting together maybe think of
getting a spider to fit and then it leaves your options
open to what chainring you want to use 32t,34t,36t etc

It doesn't look like there is a spider, just the chainring mounted directly to the crankshaft. I think it's a 36t now. Maybe going to a 34t would be better as I am frequently in my largest cog and rarely in my smallest. Good suggestion.

 

[funnel]

You'll need to change the chainring too if the chain is "sticking" on the bottom. The chainring teeth become hook shaped due to wear. It happened to me when switching to a shimano ebike chain. It's possible the kmc chain could be a better fit but I never tried. I just bought a spider and experimenting with various sizes of chainrings I found on aliexpress.

 

[-dude-]

Peterk, did you resolve the problem by replacing the chainring? I've noticed exact the same crunchy sounds you described after putting on a new chain (KMC10e)...