Can I use 9 speed components with a 10 speed MTB Rear derailleur?

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freiston
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Re: Can I use a 9 speed chain with a 10 speed Rear derailleur?

Post by freiston »

There's a table with mm cable pull per click for different systems on this page - that might help inform a decision on shifters. It does seem that Shimano MTB* 10/11 speed rear mechs need a lot more cable than other Shimano rear mechs, which is not helpful. Screenshot below:
Screenshot from 2021-10-08 22-35-13.png
I took a look at the Jtek Shiftmate compatibility tables and it looks like the Shiftmate 6 "Small" pulley groove will do the job of allowing existing 9 speed shifters to work with 10 speed MTB rear mech. Screenshot below:
Screenshot from 2021-10-08 22-45-06.png
EDIT: - The Jtek Shiftmate looks to be the cheapest solution too.
*MTB originally omitted in error and added via edit.
Last edited by freiston on 8 Oct 2021, 11:45pm, edited 2 times in total.
Disclaimer: Treat what I say with caution and if possible, wait for someone with more knowledge and experience to contribute. ;)
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freiston
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Re: Can I use a 9 speed chain with a 10 speed Rear derailleur?

Post by freiston »

GuyBoden wrote: 8 Oct 2021, 8:46pm These 10-11 speed Dia-Compe should work with a 10 speed XT Shimano Rear Derailleur.

The Right barrel is larger than the left for more cable pull

https://cdn.shopify.com/s/files/1/2196/ ... 1525753136

https://velo-orange.com/collections/shi ... t-shifters
The web page says that lever has a total cable pull of over 50mm - that's more than enough for any rear mech currently available, I think.
Disclaimer: Treat what I say with caution and if possible, wait for someone with more knowledge and experience to contribute. ;)
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GuyBoden
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Re: Can I use a 9 speed chain with a 10 speed Rear derailleur?

Post by GuyBoden »

Here are some interesting related threads.

Using 11 speed Dia-Compe ENE Down Tube Shifters
viewtopic.php?f=5&t=136955

9 and 10 speed derailleur widths
viewtopic.php?f=5&t=133497

Shimano 10 speed road versus 10 speed MTB
viewtopic.php?f=5&t=87209

New Shimano 10 speed MTB. Pull ratio.?
viewtopic.php?p=511878#p511878

Edit: I have changed the thread title due to the topic being more concerned with 9 and 10 speed component compatibility. Mainly concerning what friction shifter will work with a Shimano 10 speed MTB Derailleur.
Last edited by GuyBoden on 12 Oct 2021, 10:13am, edited 1 time in total.
slowster
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Re: Can I use a 9 speed chain with a 10 speed Rear derailleur?

Post by slowster »

A 9 speed Shimano rear derailleur can be used with a 10 speed indexed road shifter and 10 speed cassette. A 10 speed indexed road rear shifter pulls 2.3mm of cable per shift.

In contrast a 10 speed Shimano MTB rear derailleur on a 10 speed cassette requires 3.4mm of cable pulled per shift.

In other words, the 10 speed Shimano MTB rear derailleur requires virtually half as much extra cable pull compared with a 9 speed derailleur to move across the full width of the same 10 speed cassette (3.4mm/2.3mm = 1.48).

Since a Shimano 9 speed cassette differs only very slightly in total width from a 10 speed cassette, it follows that to shift a 10 speed rear MTB derailleur across a 9 speed cassette will also require your friction lever to move ~50% more than it does with a 9 speed rear derailleur.
Jamesh
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Re: Can I use 9 speed components with a 10 speed Rear derailleur?

Post by Jamesh »

Just remember tiagra 10spd is different.

Cheers James
irc
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Re: Can I use a 9 speed chain with a 10 speed Rear derailleur?

Post by irc »

freiston wrote: 8 Oct 2021, 5:05pm I find this a really interesting thread, partly due to having shopped recently for a 9 speed rear mechanism with a capacity of 45T on a 34T cassette. From what I can tell, anything fitting the bill and "higher" than Alivio in the Shimano hierarchy is pretty much obsolete - I find this horrifying - my bike is only 7 years old and it's already being pushed towards "obsolescence"
Deore still about.

https://www.sjscycles.co.uk/derailleurs ... long-cage/
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freiston
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Re: Can I use a 9 speed chain with a 10 speed Rear derailleur?

Post by freiston »

irc wrote: 9 Oct 2021, 11:47pm
freiston wrote: 8 Oct 2021, 5:05pm I find this a really interesting thread, partly due to having shopped recently for a 9 speed rear mechanism with a capacity of 45T on a 34T cassette. From what I can tell, anything fitting the bill and "higher" than Alivio in the Shimano hierarchy is pretty much obsolete - I find this horrifying - my bike is only 7 years old and it's already being pushed towards "obsolescence"
Deore still about.

https://www.sjscycles.co.uk/derailleurs ... long-cage/
Yeah, that why I said [anything higher than Alivio] "is pretty much obsolete" - although the shops are still selling them (if they have them), they're not listed in the current product range of Shimano on their website but the Alivio is (and the Alivio is only listed as a 9 speed).
Disclaimer: Treat what I say with caution and if possible, wait for someone with more knowledge and experience to contribute. ;)
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Sweep
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Re: Can I use a 9 speed chain with a 10 speed Rear derailleur?

Post by Sweep »

freiston wrote: 8 Oct 2021, 5:05pm I find this a really interesting thread, partly due to having shopped recently for a 9 speed rear mechanism with a capacity of 45T on a 34T cassette. From what I can tell, anything fitting the bill and "higher" than Alivio in the Shimano hierarchy is pretty much obsolete - I find this horrifying - my bike is only 7 years old and it's already being pushed towards "obsolescence".
Isn't the current Alivio 9 speed rear mech the beneficiary of trickle-down from the old Deore? ie very similar to it?

All of my many bikes are 9 speed apart from one which is 8.

Am quietly confident that I will be OK/get by.

I'd lay up some spares though, keep a look-out for NOS on ebay etc.
Sweep
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GuyBoden
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Re: Can I use a 9 speed chain with a 10 speed Rear derailleur?

Post by GuyBoden »

Sweep wrote: 10 Oct 2021, 8:17am
freiston wrote: 8 Oct 2021, 5:05pm I find this a really interesting thread, partly due to having shopped recently for a 9 speed rear mechanism with a capacity of 45T on a 34T cassette. From what I can tell, anything fitting the bill and "higher" than Alivio in the Shimano hierarchy is pretty much obsolete - I find this horrifying - my bike is only 7 years old and it's already being pushed towards "obsolescence".
Isn't the current Alivio 9 speed rear mech the beneficiary of trickle-down from the old Deore? ie very similar to it?

All of my many bikes are 9 speed apart from one which is 8.

Am quietly confident that I will be OK/get by.

I'd lay up some spares though, keep a look-out for NOS on ebay etc.
Instead of using an Alivio 9 speed RD, wouldn't it be nice to have the option of using the 10 speed Deore XT rear derailleur, the non clutch shadow version RD-M781 SGS.

But, there's nothing wrong with an Alivio 9 speed RD.

10 speed Deore XT rear derailleur,
Image
https://bike.shimano.com/en-EU/product/ ... 81-GS.html
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