I think Focus is using non-optimal chainrings on some of their e-bikes (jam², thron²)

[Dsab1]

I got the Ethirteen espec 160mm cranks on hand haven't put them on yet. Not sure about chainstay clearance hopefully it should be fine. And will get the bosch short crank firmware installed at same time.

Hi Akelu,
Finally got chainring and Bosch O ring in order to fit Ethirteen chainring and cranks. Looks great but have run into a problem with the drive side crank arm , the clearance between crank arm and the rubber moulded chainstay protector is marginal and under load ( twisting effect ) it comes into contact with the rubber protector, I have filed it down a fair bit but I think the only way to have it working successfully is to space it out with a washer between the locknut and the crank arm, so back to my local bike shop to hopefully rectify the problem !

 

[LanzaSteve]

Hi guyS, fitted the e13 chainring, new xtr chain, new cassette, now using Squirt chain lube. What a difference! It’s never ran so smoothly. Can’t recommend this enough.

 

[aa1320]

Just got my LBS swap to E13 chainring, but its rubbing against the chainguide at 1-3 gear??

 

[roccobarocco]

I think the are using now the correct ones, SH12...see picture, sorry for the quality

 

[Akelu]

Just got my LBS swap to E13 chainring, but its rubbing against the chainguide at 1-3 gear??

Sorry, my version did not come with a chainguide so i cannot advise.

 

[Akelu]

Got a better picture of the updated chainring from a youtube review of 2021 thron model.. (Mine was 2021 too though)
Now clearly with the big difference in the teeth profile you can see why the old one was a problem..

contrast that with the original

 

[Landy Andy]

Mine is the 2021 model but old ring.

 

[Akelu]

Wow, you can really see how much the chain has worn away at the chamfered edges of the big teeth!
I'd imagine that chainring probably performs okay now, that it's been worn down so much.
How much distance have you logged on that bike?

 

[Landy Andy]

Wow, you can really see how much the chain has worn away at the chamfered edges of the big teeth!
I'd imagine that chainring probably performs okay now, that it's been worn down so much.
How much distance have you logged on that bike?

 

[niczoom]

Good news. Thanks to this thread. I contacted my LBS who in turn contacted Focus Australia and am now getting it replaced along with a new chain under warranty. Thanks again for your time and effort in posting this issue! I have ridden approx 1120km since April. Albeit my chainsuck has reduced now, probably due to wear on the chainring and chain. But no doubt it would return if a new chain was fitted. Im looking forward to a smoother ride with the proper chainring!

 

[Zimmerframe]

Mine seems to have this .. feels very sucky and there's metal particles in only a couple of km's ..

No markings on it.

 

[niczoom]

Wow, that seems to be a lot of wear! You can see quite clearly that a lot of the black has worn away too. Ive attached a phot of my chainring which is after approx 1100km. My bikes in at the LBS to fit the new chainring and will be getting in back in a few hrs from now

 

[Akelu]

It's normal for the black to wear away at the contact points on all chainrings. Obviously its going to show less wear if it had the proper chain/chainring combo and was making contact in the right spots though..

Interesting that your chainring has no written markings Zimmerframe maybe you could check on the rear side for a model #?

 

[B1rdie]

On my spectralon with shimano 8000 I started having the same problem as the OP since I first had to change drivetrain parts, it has 11 speeds. It seems the tolerance on the chainring is critical.
I have had the sensation these noises were associated to bearing wear, since there is so much hype about this on the forum.
Finally last month i resolved to try and use a non wide/narrow zee chainring and all those noised disapeared.
Now my motor at 4.500 km is as “silent” as new. Will try to find a new original shimano N/W chainring to replace the zee one, but its allmost impossible here. But stay away from cheap after market chainrings.

 

[Zimmerframe]

Interesting that your chainring has no written markings Zimmerframe maybe you could check on the rear side for a model #?

All I have is NW34T

So Narrow Wide 34 Teeth ..

 

[themoon]

One of the first upgrades I've done on my bike is replacing stock 34 chain ring with 38 one - same as stock, shimano, for e8000 motor. A big difference, using cassette more fully now. After 3000 km still no noticeable wear on a chainring - though replaced a chain, since I ride all year round, in pretty muddy/snowy weather as well

 

[Akelu]

All I have is NW34T
So Narrow Wide 34 Teeth ..

Hmm seems like a pretty generic narrow wide chainring. Can't find anything on it.. My guess based on looking at the teeth in your pic is that its probably not hyperglide+ tooth profile. I would consider replacing the chainring and chain. Go to your dealer and show them the problem, tell them that you suspect the chainring is not correct tooth profile and get them to ask focus for replacements.

 

[philippe1]

had the same problem first day on with my spectral-On 2021, chain (12sp) sticks to the wide teeth of the (alu) chainring, filed the wide teeth down a tiny bit(at the base), problem solved. Have 3000 km since (alternating two chains)

 

[Akelu]

Yeah nah, theres no way ill be doing that Philippe1.

Just contact the place of purchase to have the manufacturer send out the correct part, or get a refund because the item is not fit for purpose (and is actually a danger, chain suck can throw you over the handlebars, so its pretty dodgy that they are making the conscious decision to use these incompatible chainrings, or at least not do a recall/contact all existing sales to offer a swap out)

Also, the tolerances on hyperglide+ 12 speed chains are so tight. You would have to spend so much time filing properly each tooth to get it to match up anywhere close to where it should be, and youd still not be quite there. I don't want to be wearing out the chain in a certain way which will then impact drivetrain longevity. I'm sure it works for you, and im sure its much better then it was, but theres no way i would be doing that. You would also be possibly voiding your bikes warranty.