The QUICK question thread.....

treble

Likes Dirt
I know 10/11/12 speed chains are different widths, but are front chain rings speed specific?
I'm trying to figure out if I'm going to have trouble running 10 speed with a '12 speed' crankset.
 

moorey

call me Mia
I know 10/11/12 speed chains are different widths, but are front chain rings speed specific?
I'm trying to figure out if I'm going to have trouble running 10 speed with a '12 speed' crankset.
What cranks? More specifically, what chainring?
 

treble

Likes Dirt
What cranks? More specifically, what chainring?
Deore M61020 cranks with the standard narrow wide chainring
I know it's designed for a 0.7mm narrower chain. But I cant find anwhere if the Internal width of the chain is different between speeds, I have to assume it is slightly.
 

moorey

call me Mia
Deore M61020 cranks with the standard narrow wide chainring
I know it's designed for a 0.7mm narrower chain. But I cant find anwhere if the Internal width of the chain is different between speeds, I have to assume it is slightly.
Inner width is basically the same, it’s more the outer width. An 11 or 12sp cassette will be an issue with a 10sp chain, but the chainring won’t be.
I should have asked what cassette/speed.
 

treble

Likes Dirt
Inner width is basically the same, it’s more the outer width. An 11 or 12sp cassette will be an issue with a 10sp chain, but the chainring won’t be.
I should have asked what cassette/speed.
Ah Ok cool. Should be right then. Everything else chain/cassette/derailleur/shifter is Shimano 10 speed. Just needed a boost crankset and they are all listed as 12 speed
Thanks!
 

moorey

call me Mia
Ah Ok cool. Should be right then. Everything else chain/cassette/derailleur/shifter is Shimano 10 speed. Just needed a boost crankset and they are all listed as 12 speed
Thanks!
Wait. I hadn’t opened your link....if it’s a 12sp shimano chainring, you’re outta luck I reckon. They are specific to the shimano 12sp chain.
@The Duckmeister ?
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
Wait. I hadn’t opened your link....if it’s a 12sp shimano chainring, you’re outta luck I reckon. They are specific to the shimano 12sp chain.
@The Duckmeister ?
This got me curious, so I went and had a play with some spares in the garage...

So there's no reason you can't put a 9/10/11sp on the Shimano 12sp chainrings, but the chain retention of the narrow wide 12sp chainring will lose it's effect with the 9/10/11sp chain as the chainring teeth are narrower with 12sp. The wide teeth on the lightly worn 30t 12sp chainring shown are 2.9mm wide, but 11sp are a lot wider. I only have a old Wolftooth 11sp ring here, but the wide teeth on it are around 3.7mm, so the 11sp chain will go on 12sp rings but be loose, but 11sp rings will not fit in the 12sp chain.

FWIW - The inner plates on the 12sp chains are slightly longer, which would still make the 12sp chains incompatible with conventional narrow-wide chainrings even if they were the right width.

The 12sp chainring has a little extra bevel on the edges of the wide teeth to accomdate these longer teeth.

HG701 11sp chain (loosely) on a Shimano 12sp 30t chainring:
372966


Close up, circled tooth shows the extra bevelling (cutaway edges) on the wide teeth on Shimano 12sp chainrings:
372967


9/10/11sp chains don’t have the extended inner plates 12sp chains do, so don't have anything that'll cause any issues with these grooves, but will be loose on the plates so a dedicated 9/10/11sp chainring would be adviseable to avoid dropping chains.
 

moorey

call me Mia
This got me curious, so I went and had a play with some spares in the garage...

So there's no reason you can't put a 9/10/11sp on the Shimano 12sp chainrings, but the chain retention of the narrow wide 12sp chainring will lose it's effect with the 9/10/11sp chain as the chainring teeth are narrower with 12sp. The wide teeth on the lightly worn 30t 12sp chainring shown are 2.9mm wide, but 11sp are a lot wider. I only have a old Wolftooth 11sp ring here, but the wide teeth on it are around 3.7mm, so the 11sp chain will go on 12sp rings but be loose, but 11sp rings will not fit in the 12sp chain.

FWIW - The inner plates on the 12sp chains are slightly longer, which would still make the 12sp chains incompatible with conventional narrow-wide chainrings even if they were the right width.

The 12sp chainring has a little extra bevel on the edges of the wide teeth to accomdate these longer teeth.

HG701 11sp chain (loosely) on a Shimano 12sp 30t chainring:
View attachment 372966

Close up, circled tooth shows the extra bevelling (cutaway edges) on the wide teeth on Shimano 12sp chainrings:
View attachment 372967

9/10/11sp chains don’t have the extended inner plates 12sp chains do, so don't have anything that'll cause any issues with these grooves, but will be loose on the plates so a dedicated 9/10/11sp chainring would be adviseable to avoid dropping chains.
TL DR. I mean, thanks for that work, mate.
 
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