Rear derailleur question...

[oldguy00]

Hi all,

Will an 11 speed derailleur, like ultegra 6800 (mechanical) work with an otherwise 10 speed shimano system?
A friend just bought a NOS bike that came with 10 speed 105. Works great, but she needs a really big cassette on the back (like a 32 cog), and thus we are on the hunt for a med/long cage rear derailleur.
If an 11 speed won't work, what 10 speed long cage options are there, that are still easy to find online?

Thx!

[eddief]

you can easily shift big cassettes with 9 speed mountain derailleur. on the other hand if you just need to go to 32 teeth, then I'd think a 6800 RD would do the job. Pretty sure it is compatible with 10 shifters. or like this:

http://www.chainreactioncycles.com/us/en/shimano-105-5701-10-speed-rear-mech/rp-prod85966?gs=1&utm_source=google&utm_term=&utm_campaign=Chain+Reaction-US-PLA-PLA-All-All-SE-Shopping-QLB+Test+Product&utm_medium=base&utm_content=mkwid|sAqiTI0Bs_dc|pcrid|101472496728| pkw||pmt||prd|333207US

[dave thompson]

The 11-speed rear der won't work. The best solution for running a big cassette on a 10-speed is use a Shimano 9-speed MTB rear derailleur. This is a very common thing, particularly among touring riders.

[oldguy00]

Thanks all. Just saw this on ebay, thinking it might be a good solution...

http://www.ebay.com/itm/Shimano-Tiagra-4700-10-Speed-Rear-Derailleur-Grey-GS-Long-Cage-/122533735226?epid=1342136985&hash=item1c87946b3a:g:KEoAAOSwlndZNSyG

[oliver1850]

Here's an option that will accept a 34 large cog:

http://planetcyclery.com/shimano-deore-long-cage-black-rear-derailleur

[Bradford]

You want an XT M750 long cage rear derailleur. Always available on eBay, although you usually have to wait a bit to get one that looks new. I'm running 4 of them with various flavors of 10!speed and cassettes up to 34.

[8aaron8]

Thanks all. Just saw this on ebay, thinking it might be a good solution...

http://www.ebay.com/itm/Shimano-Tiagra-4700-10-Speed-Rear-Derailleur-Grey-GS-Long-Cage-/122533735226?epid=1342136985&hash=item1c87946b3a:g:KEoAAOSwlndZNSyG

This option will require you to also buy the 4700 shifters as the cable pull was changed with this iteration.

[dave thompson]

^^Aaron is correct^^ 4700 derailleur aren't compatible with other Shimano 10-speed shifters.

[eddief]

cuz he knows.

[oliver1850]

This option will require you to also buy the 4700 shifters as the cable pull was changed with this iteration.

So does the 4700 RD have 11 speed geometry?