10 speed rear mech with 9 speed system?

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Sweep
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10 speed rear mech with 9 speed system?

Postby Sweep » 18 Oct 2020, 10:16am

Apologies if asked before.

Quick question - can you use a 10 speed rear mech with a drivetrain/system that is 9 speed - chain, cassette etc (am assuming shifters no problem at all) - in short I guess I am asking whether the 9 speed chain will run through it without problems.

Seem to remember that brucey says a 10 speed front mech shouldn't be used with a 9 speed system due to the cage being tighter, but that you can use a 9 speed rear mech with an 8 speed system.
Sweep

Brucey
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Re: 10 speed rear mech with 9 speed system?

Postby Brucey » 18 Oct 2020, 10:19am

shimano 10s 'road' RD, yes (but not 4700 or GRX)

shimano 10s MTB RD , no, not if you want indexing to work

re FD cage width; you will know already if you are likely to cause the cage to rub. If you do, don't go narrower.

cheers
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Sweep
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Re: 10 speed rear mech with 9 speed system?

Postby Sweep » 18 Oct 2020, 10:29am

Brucey wrote:
shimano 10s MTB RD , no, not if you want indexing to work

re FD cage width; you will know already if you are likely to cause the cage to rub. If you do, don't go narrower.

cheers


Thanks brucey - be gentle with me for it's early on a sunday - am having trouble getting my head round the indexing issue - aren't the clicks on the shifter? - I don't recall any clicks on the rear mech - doesn't it just pull/click into place depending on where the shifter pulls it to/let's it fall back to? As I said, please be gentle - have a terrible feeling that I have missed something obvious/am making a right nit of myself.

As you may have guessed I have stopped at 9 speed drivetrains and don't intend to go any further.

slightly encouraged by your last point I may experiment with a 10 speed front mech I acquired - I have a stock of flat bar triple clickshifters with trimming functions.
Sweep

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Re: 10 speed rear mech with 9 speed system?

Postby Brucey » 18 Oct 2020, 10:35am

it is all to do with shift ratios. The shifter pulls a length of cable and the RD moves in proportion to it. However not all RDs move in the same proportion.

some light reading

https://en.wikibooks.org/wiki/Bicycles/Maintenance_and_Repair/Gear-changing_Dimensions

cheers
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Sweep
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Re: 10 speed rear mech with 9 speed system?

Postby Sweep » 18 Oct 2020, 10:40am

Brucey wrote:it is all to do with shift ratios. The shifter pulls a length of cable and the RD moves in proportion to it. However not all RDs move in the same proportion.

some light reading

https://en.wikibooks.org/wiki/Bicycles/Maintenance_and_Repair/Gear-changing_Dimensions

cheers

many thanks as always brucey, but cripes - haven't seen anything that daunting looking since I escaped sunday school aged 10.
I may be some time.
Sweep

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Re: 10 speed rear mech with 9 speed system?

Postby thelawnet » 18 Oct 2020, 12:17pm

Sweep wrote:
Brucey wrote:it is all to do with shift ratios. The shifter pulls a length of cable and the RD moves in proportion to it. However not all RDs move in the same proportion.

some light reading

https://en.wikibooks.org/wiki/Bicycles/Maintenance_and_Repair/Gear-changing_Dimensions

cheers

many thanks as always brucey, but cripes - haven't seen anything that daunting looking since I escaped sunday school aged 10.
I may be some time.


That page is rather outdated.

Essentially:

* up to 9-speed largely the same, and Shimano acknowledge that you can mix and match derailleurs in their docs.
* 10 speed road (Dura-Ace 7800) - 2003 - still the same, but as more cogs are packed into the same amount of space, the amount of cable pulled to move one gear has got increasingly small, which makes the system fussy about adjustment
* 2008 - Shimano decides to hide its cables under the bar tape, as with Campagnolo and SRAM, for Dura-Ace 7900 (also Ultegra 6700 and 105 5700), which adds extra bends and friction. They revise the front derailleur pull ratio, and it works well. They do not revise the rear derailleur, and it works.... not so well.
* 10-speed MTB 2010 (Dyna-Sys) - several years have elapsed since 10-speed road, and Shimano decided that they would be better off pulling more cable (more shift force required, but easier for adjustment), as perhaps the old pull ratio was no longer well-suited to 10-speed. They pull much more cable than older generations.
* 11-speed road 2012 - Shimano decides to come up with a new ratio somewhere between the 10-speed MTB and the older ratio, so that there's not too much force required, but so that it can overcome the extra friction introduced by the hidden cables, so they now have '11-speed road' RDs (even though there is no 'speed' inherent to the RD, since the indexing is in the shifter) distinct from everything else.
* 11-speed MTB 2014 - Shimano realises it can make more money by claiming that everything is incompatible, so says you need a '11-speed MTB RD' for your 11-speed shifters, even if 10-speed worked fine, people are encouraged to 'upgrade' (which might have been necessary, as 11-speed came with larger cassettes, though you could in fact use a 11-speed HG700/HG800 11-34t cassette just fine)
* 2015 - Shimano wants to update their 10-speed Tiagra groupset to have hidden cables, which the previous generation did not, in order to provide a distinction between what-was-then 10-speed 105 and 10-speed Tiagra; now 105 is 11-speed, so that's enough distinction to keep the marketing people happy. Rather than do what they would previously do, which is churn out a re-painted old 105 10-speed derailleur/shifter, they acknowledge that it was a bit rubbish, and instead they modify their 11-speed 105 shifters for 10 speeds, and stick a 'Tiagra' sticker on the '11-speed' RD
* 12-speed MTB 2018 - more of the same as with 11-speed: Shimano claims you need a specific 12-speed MTB RD
* 2019 - Shimano releases a new 'gravel' (aka 'road') product line, as that's the latest way to print money. To create arbitrary product differentiation, they have a '400' series at 10 speeds, '600' & '810' at 11-speeds. They confirm that they've dumped the old pull ratio, as both use the same derailleurs.
* 2020 - Shimano updates their MTB groupsets to have more cogs and poorer build quality. They release two '11/10' speed rear derailleurs, confirming there was never any difference between '11-speed MTB RD' and '10-speed MTB RD', whatever they said in their charts.


The 11-speed MTB generation ('DynaSys 11') was Shimano's last attempt to promote multiple chainrings to the hostile market, and they put out several graphs showing how crappy 1x is:

Image

Image

It's based on a 11-40t cassette with a nice graph showing how well-spaced it all is;

Image

The market was not impressed, so Shimano had to put out a 11-42t cassette which replaced 24-27-31-35-40 with 24-28-32-37-42.

This wasn't good enough either, so they pushed out a 11-46t which simply replaced the 42t with a 46t, which was awful rubbish, but sold like hotcakes as a '1x system'.

The 12-speed generation is sadly absent any graphs showing how much less efficient it is than the preceding ones (though to be fair, they have put out 36/26 doubles for 12-speed, it's just they don't sell, because everyone wants massive heavy weights on their rear axle), but at least Shimano knew they had to design it around 1x, so the boat anchor cassette was there from day one.

Shimano's original 11-speed MTB with a 3x chainset and a 11-40t was a very good design, but a sales failure and saw them destroyed by SRAM which boasted bigger, more expensive cassettes, RDs with more plastic in, and other such delights, so Shimano learned its lessons and have dutifully downgraded the quality and upgraded the marketing, rebranding 'Alivio' as 'Deore' and other such tricks, and they seem to be re-taking marketshare.

One presumes the delay to 12-speed road is the conflict between the desires of the marketing department and those of the engineers.

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Re: 10 speed rear mech with 9 speed system?

Postby Brucey » 18 Oct 2020, 4:31pm

thelawnet wrote:

That page is rather outdated.

.


yes but it contains pretty much everything you need to know about running a 10s mech on a 9s system, and relatively little that you don't.

cheers
Last edited by Brucey on 18 Oct 2020, 5:40pm, edited 1 time in total.
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Sweep
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Re: 10 speed rear mech with 9 speed system?

Postby Sweep » 18 Oct 2020, 5:26pm

Thanks for that as well lawnet.
It also makes me feel happy and chilled to be a 9 speed flat bar rider.
(One 8 speed as well)
And to never let them tempt me any further.
Sweep

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Re: 10 speed rear mech with 9 speed system?

Postby thelawnet » 18 Oct 2020, 5:48pm

Brucey wrote:
thelawnet wrote:

That page is rather outdated.

.


it contains pretty much everything you need to know about running a 10s mech on a 9s system, and relatively little that you don't.


It shows all the issue of a 'Wiki' - an article edited by multiple people and containing outdated statements that are contradicted elsewhere in the same piece.

"The rear shift data listed in these tables is the same for both MTB (mountain bike) rear shifting, and road bike, (drop-handlebars and racers) rear shifting. For front shifting, (section still needs completion, and data is almost non-existent), the cable pull often is different between the two types of bike. For example, Shimano shifters have different cable pulls for their MTB and road series bikes." [this was true when first added, but became no longer

The 'version by committee' there is just confusing. CJ explains at the source, originally written in 2003 (!): https://www.cyclinguk.org/cyclists-libr ... s/shimergo

"
OId Dura-Ace

The first Shimano groupset to go indexed was Dura-Ace. It was launched in 1985 with a slightly bigger shift ratio (hence shorter cable pull to get the same shift) from what soon became the Shimano standard, and remained like that until 1997. Currrent Dura-Ace mechs are nevertheless designed with an alternative cable route that gives the old shift ratio, so they can also work with old Dura-Ace shifters."

but reading that wikified version there's no indication of what 'old dura-ace' might mean (something rather different in 2003 from 2020!).

Also the SRAM stuff there is at least a decade out-dated as well and rather confusing - SRAM aren't interested in making 'Shimano-compatible' any more - they have 1:1, Exact-Actuation and X-Actuation.

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Re: 10 speed rear mech with 9 speed system?

Postby mercalia » 18 Oct 2020, 5:52pm

mtb and road shifters pull differnt amounts of cable? My 1-Down has mtb V brakes and require a travel agent to magnify the pull with the RSX sti shifters

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Re: 10 speed rear mech with 9 speed system?

Postby Brucey » 18 Oct 2020, 6:03pm

mercalia wrote:mtb and road shifters pull differnt amounts of cable? My 1-Down has mtb V brakes and require a travel agent to magnify the pull with the RSX sti shifters


you are talking about brakes not shifters.

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Re: 10 speed rear mech with 9 speed system?

Postby Brucey » 18 Oct 2020, 6:11pm

thelawnet wrote:
Brucey wrote:
thelawnet wrote:

That page is rather outdated.

.


it contains pretty much everything you need to know about running a 10s mech on a 9s system, and relatively little that you don't.


It shows all the issue of a 'Wiki' - an article edited by multiple people and containing outdated statements that are contradicted elsewhere in the same piece....


it seems pretty clear to me and is accurate for the items of interest. Remember that Sweep is asking about 10s mechs with a 9s system, and secondly (but perhaps of primary importance) is asking how indexing systems work. Not that it is uninteresting per se, but quite what shimano's plans for world domination with the latest 12 speed garbage have to do with either thing is beyond me.

The beauty of the WIki article is that you can edit it. So if you have useful information to contribute or suggestions for things that might clarify the page, why not add them to the page instead of moaning about it?

cheers
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thelawnet
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Re: 10 speed rear mech with 9 speed system?

Postby thelawnet » 18 Oct 2020, 7:19pm

Brucey wrote:
The beauty of the WIki article is that you can edit it. So if you have useful information to contribute or suggestions for things that might clarify the page, why not add them to the page instead of moaning about it?


The article would need to be rewritten from scratch so as to focus rather more on the concerns of 2020 than those of 2003. While I'm sure this would be useful, I'm not equipped with the knowledge of the various SRAM, Campagnalo, Microshift, etc. to do this.

At least I think it would. Problem with a Wiki is someone else might disagree with that and wipe out your changes. I'd rather write about, say the marketing and technical decisions rather than sprocket spacing and so on.

Technical data about bicycles (and lots of other things) tends to be compiled by one man; other option is a paid technical staff compiling such things. Wikis don't seem to be an effective system. Have spent time on them in the past. Don't like them much.

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Re: 10 speed rear mech with 9 speed system?

Postby MikeF » 18 Oct 2020, 8:17pm

Sweep wrote:Thanks for that as well lawnet.
It also makes me feel happy and chilled to be a 9 speed flat bar rider.
(One 8 speed as well)
And to never let them tempt me any further.
I've just upgraded a bike from 8 speed to 9 speed - 11/32 cassette to 11/34. I had to buy a new bar end changer and the RD adjustment seems very much more critical, but I much prefer the gear ratios.
"It takes a genius to spot the obvious" - my old physics master

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Re: 10 speed rear mech with 9 speed system?

Postby Mick F » 19 Oct 2020, 8:48am

Sweep wrote:Quick question - can you use a 10 speed rear mech with a drivetrain/system that is 9 speed - chain, cassette etc (am assuming shifters no problem at all) - in short I guess I am asking whether the 9 speed chain will run through it without problems.
I can only talk about Campag, but 9sp and 10sp front and rear mechs are fine being mixed.
Not tried any other make of chain than Campag one, and not tried any other chainset than Campag either.
Mick F. Cornwall