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I need easier gear but I already got 34/50 and 11-32 (11 speed edition), I read online it's possible to use long cage derailleur with 34 cog.

Shimano doesn't make 11-34, so I was thinking of buying 11-34 from the previous edition 10 speed cassette and drop 11 and have 34,32,...,12

Any advice on such setup? Is there a difference in the cogs width?

Jed

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  • I'm confused. You want to use a 10 speed cassette with a 11 speed shifter?
    – Batman
    Commented Nov 20, 2016 at 17:49
  • No, I wanted to borrow 34 cog from 10 speed and put it on 11speed cassette. 11 speed cassettes are not offered with 34 , the biggest you can get is 32.
    – Jed
    Commented Nov 20, 2016 at 18:16
  • Sounds like a lot of work for minimal gain. Can you fit a MTB cassette instead? Somehting like jensonusa.com/Shimano-XT-CS-M8000-11-Speed-Cassette is available in 40/42/46 teeth.
    – Criggie
    Commented Nov 20, 2016 at 18:51
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    @Criggie - as far as I can tell, 11 speed has ruined everything forever. The cog pitch is a bit different between road and mountain -- 3.7 mm vs 3.9 mm.
    – Batman
    Commented Nov 20, 2016 at 19:02

2 Answers 2

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You can't just take a cog off a 10 speed cassette and put it on a 11 speed cassette -- the big one is attached to the spider, so you can't really remove it and use it to build your own cassette.

There are a few options (choose one):

  1. Use a Wolf Tooth RoadLink to mount the derailleur lower and use a bigger cassette
  2. Use a slightly smaller front chainring (46t or 48t)
  3. Do a cage swap from a long cage mountain derailleur
  4. Move to SRAM shifters and derailleurs or a lower speed Shimano group (10 speed?)
  5. Use a JTek Shiftmate 8 (or 8A, preferrably) and a Shimano 11 speed mountain derailleur and a bigger cassette
  6. Use bar end shifters and a different derailleur
  7. Just try SRAM's 11-36 road cassette and see if it works by adjusting the derailleur (linked article claims putting the B-screw down 2/3rds of the way makes it work fine on an Ultegra).

I'd probably start with option (7) and failing that, opt for option (1) or (5). Other Shiftmate configurations are possible with different cassettes (e.g. 11->10 speed and then handling derailleurs+cassettes appropriately).

Note that a 50/34 + 11-32 already gives you a pretty large range, provided you're shifting correctly.

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  • I found 3rd party 12-36 shimano compatible cassette. sjscycles.co.uk/cassettes/… The cost is a bit prohibitive but it seems it can be installed without any further modifications to the bike. Has anyone tried such setup?
    – Jed
    Commented Nov 20, 2016 at 21:29
  • IRD makes good quality equipment, but why not just buy the SRAM pg-1170 11-36? You still need to do a B-screw adjustment either way. It's less than half the price.
    – Batman
    Commented Nov 20, 2016 at 21:52
  • @batman "Use a slightly smaller front chainring (46t or 48t)" I would understand this if the small chain ring ought to be smaller. Wouldn't the large chain ring matter only in the case of very extreme cross chaining? Or did you mean to go down with both chain rings? Why is replacing the smaller chainring not your first choice? Would it require also a new crankset or derailleurs?
    – gschenk
    Commented Nov 20, 2016 at 22:23
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    @gschenk - The large chainring brings down the top gear ratios, yes. Replacing the smaller one is an option too (but you'll likely have to replace the big one as well due to gap requirements). You have to still worry about derailleurs and cranks in this case. Depending on if you're shifting properly or not, it may or may not help. Just putting on the bigger road cassette and seeing if you can clear it is easier and quicker.
    – Batman
    Commented Nov 21, 2016 at 0:11
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It is possible, but not guaranteed, that a Shimano 105 medium cage rear mech (presumably what you have) will take a 34T sprocket - as you say there are reports of people trying this successfully.

Another option however is to change your chainset, to either a MTB double (say 40/28 - which will obviously be a big difference) or some of the super-compact road cranksets that are now available (e.g 48/32)

Replacing an individual sprocket may not be possible depending on your cassette, the larger sprockets are often joined together. I think the lock nut also screws into the smallest sprocket so you may not be able to replace that either. In any case Shimano absolutely do make 11-34T cassettes - for their mountain bike groupsets.

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