Would 9-speed chain work with a (partial) 10-speed drivetrain?

[biker.caliente]

Hi, All,

I plan to build my boy his first road bike using my 9-speed spare bike and the 10-speed spare parts in my stash. Like to know if either of the following options works and which would work better. Thanks in advance.

#1 - 10-speed double crankset, BB (hollowtech), and 10-speed cassette but with a 9-speed chain. (all Shimano DA).
#2 - 9-speed triple crankset, BB, 10-speed chain and 10-speed cassette. Again all Shimano DA.

Thanks in advance.

BC

[cribbit]

Chainrings won't matter for chain width, but I wouldn't do 11s chain on 9s chainrings unless you had to. I know it won't work with even older chainrings.

You can get away with going up/down one speed on chain but it's not ideal. You'll have much harder to adjust shifting for index - much more feasible on friction shifting.

[thwart]

You 'should' be able to shorten that 10 speed chain in option #2 so it would work in option #1. You may want to use a quick-link if you don't have a chain peening tool, though.

Triples can be a little complicated for a newbie roadie, at least IME. Keep it simple.

Seems you can go up a speed in chains (for ex., using a 10 spd chain in a 9 spd drivetrain) with better function than if you go in the opposite direction.

[choke]

It will probably work but it may not shift as well as it should. #2 would be the better option IMO since the cassette and chain are matched....the crank won't care IME.

I use 9sp chains on my vintage 6 and 7sp bikes. They work fine and I have zero problems, though those are friction shifted. I also have an 11sp bike that has a crank with rings that are labeled 9/10sp....again, zero problems.

The inner width of all chains from 6sp to 11sp is the same, only the outside width is changed.

[boywander]

It will probably work but it may not shift as well as it should. #2 would be the better option IMO since the cassette and chain are matched....the crank won't care IME.



I use 9sp chains on my vintage 6 and 7sp bikes. They work fine and I have zero problems, though those are friction shifted. I also have an 11sp bike that has a crank with rings that are labeled 9/10sp....again, zero problems.



The inner width of all chains from 6sp to 11sp is the same, only the outside width is changed."The inner width of all chains from 6sp to 11sp is the same, only the outside width is changed."

I don't think that's entirely true. I will follow up after checking the inner widths.


Sent from my LG-M322 using Tapatalk

[choke]

"The inner width of all chains from 6sp to 11sp is the same, only the outside width is changed."

I don't think that's entirely true. I will follow up after checking the inner widths.


Sent from my LG-M322 using Tapatalk From https://www.velonews.com/gear/tech-faq-chain-width-explained-compatibility-queries-answered/

Chain width, as defined by standard methods of measuring chains, is 3/32-inch on all bicycle derailleur chains. But this is NOT the “width” people are talking about when they say, “an 11-speed chain is narrower than a 10-speed (or 9-speed or 8-speed, etc.) chain.” Yes, chains have gotten narrower as the number of rear cogs has increased in bicycle drivetrains, BUT it is only the outside width dimension that has decreased, and really, we are actually describing the length of the roller pins, which is shorter on 11-speed chains than on 10-speed chains.

Rest assured, that is not an issue, because 11-speed chains are still 3/32-inch-width chains, just like 5-speed chains were. And the widths of cog teeth on cassettes has also stayed essentially the same over the decades.

[MikeD]

A 9s chain probably won't work on a 10s cassette because the chain is too wide and will hit the adjacent cogs.

[cribbit]

A 9s chain probably won't work on a 10s cassette because the chain is too wide and will hit the adjacent cogs.

It fits and shifts but is harder to adjust. Done it on plenty of bikes.

[cribbit]

RE: Inner width - I've definitely had a bike where it used an old crank with old chainrings and I tried using a 10spd chain and the teeth were too fat and got stuck. Put on a 8 spd chain and it was fine. No idea if that was the true cause or what.

[biker.caliente]

Thanks for the feedback. I just realized that I made error on the original post. I've got just one 9-speed DA chain (no 10-speed chain) and would love to reuse it for the project. I think the boy is lucky enough to have his first road bike with all DAs. Trying not to spend for a 10-speed DA chain.

So here are the corrected arrangements I have in mind. Sorry to have wasted your time but would love to hear your feedback again.

#1 - 10-speed double crankset, BB (Hollowtech II), and 10-speed cassette but with a 9-speed chain. (all Shimano DA).
#2 - 9-speed triple crankset, BB-7703, 9-speed chain and 10-speed cassette. Again all Shimano DA.

[choke]

It appears that a 9sp chain is 0.5-1.0mm wider than a 10sp chain. The 10sp derailleurs might be thinner between the cages than a 9sp so the chain could rub them. The cogs on the 10sp cassette will be closer together so you may get rubbing or excess noise. It may not index well.

Whether or not that will matter is hard to say. I would give it a try and see what happens.

On the other hand a KMC 10sp chain can be purchased for around $20.

[DeBike]

I am using a 9 speed chain with 10 speed Shimano 11-23 cassette, early 105 front/ rear derailleur and DT shifters, set in friction mode, and it shifts great. The front is actually an IRD double with 46/32. Everytime I think about putting STI's on it, I vote myself down and leave it as is.

[oldpotatoe]

Thanks for the feedback. I just realized that I made error on the original post. I've got just one 9-speed DA chain (no 10-speed chain) and would love to reuse it for the project. I think the boy is lucky enough to have his first road bike with all DAs. Trying not to spend for a 10-speed DA chain.

So here are the corrected arrangements I have in mind. Sorry to have wasted your time but would love to hear your feedback again.

#1 - 10-speed double crankset, BB (Hollowtech II), and 10-speed cassette but with a 9-speed chain. (all Shimano DA).
#2 - 9-speed triple crankset, BB-7703, 9-speed chain and 10-speed cassette. Again all Shimano DA.

The 9s chain would probably work but would be finicky and certainly noisy.
A 10s like KMC is really inexpensive. Get one and don’t have the youngun wonder if the noisiest is how this stuff works.
Crank/chainrings don’t care. CRs are all about the same width, 8s-10s, the CRs just got closer together on some cranks, some CRs.

[ultraman6970]

+1... will work fine but tad noisy.

[biker.caliente]

Thanks to everyone offering your generous opinion/suggestion.

[boywander]

RE: Inner width - I've definitely had a bike where it used an old crank with old chainrings and I tried using a 10spd chain and the teeth were too fat and got stuck. Put on a 8 spd chain and it was fine. No idea if that was the true cause or what.


That’s the point I was thought was the width. But the article in the link above refers width differently.