Rear derailleur compatibility
Discussion
Shifting started to become a bit hit and miss on the road bike so it was time to give it a strip down and good clean. I currently have a 9 speed sora derailleur but a friend has given me a Shimano 105 (think it's the 11 speed 5800) derrailier so thought I may has well use this if it will work.
It is my understanding that the derrailier is fairly dumb in that it doesn't really care how many gears it is shifting as the indexing is defined by the shifter and the derailleur just does as it's told.
However I have set it up and it shifts perfectly between the bottom 8 gears but to get it to shift into top the tension needs to be taken right down which then means it won't shift back down nicely.
So before I spend more time on trying to set it up I wanted to ask you all if you think it should actually work at all on a 9 speed setup?
Cheers
It is my understanding that the derrailier is fairly dumb in that it doesn't really care how many gears it is shifting as the indexing is defined by the shifter and the derailleur just does as it's told.
However I have set it up and it shifts perfectly between the bottom 8 gears but to get it to shift into top the tension needs to be taken right down which then means it won't shift back down nicely.
So before I spend more time on trying to set it up I wanted to ask you all if you think it should actually work at all on a 9 speed setup?
Cheers
You're partially correct, the mech is dumb, and it 'doesn't care' about indexing.
However, I believe the 11 speed groupsets use a different cable pull ratio to the 10/9/8 speed sets. Specifically more cable movement for a 'click' on the indexing. So 11 speed mechs are built around a different rate of cable movement, which makes them incompatible with the earlier 10 and lower gear.
Not sure that really tallies with your symptoms tho.. Would be a good idea to be sure exactly what the mech is. If it's from a (8?)/9/10 speed groupset you're good, 11 speed, no..
However, I believe the 11 speed groupsets use a different cable pull ratio to the 10/9/8 speed sets. Specifically more cable movement for a 'click' on the indexing. So 11 speed mechs are built around a different rate of cable movement, which makes them incompatible with the earlier 10 and lower gear.
Not sure that really tallies with your symptoms tho.. Would be a good idea to be sure exactly what the mech is. If it's from a (8?)/9/10 speed groupset you're good, 11 speed, no..
As above, different actuation ratio on the 11 speed stuff of 1.4 vs 1.7, meaning indexing with your existing shifters and the rear mech won't work properly.
I am also not 100% certain but as 11 speed uses a narrower chain, achieved with narrower outer link plates, the jockey wheels and spacing is narrower, so your 9 speed chain may not run through properly.
I am also not 100% certain but as 11 speed uses a narrower chain, achieved with narrower outer link plates, the jockey wheels and spacing is narrower, so your 9 speed chain may not run through properly.
upsidedownmark said:
You're partially correct, the mech is dumb, and it 'doesn't care' about indexing.
However, I believe the 11 speed groupsets use a different cable pull ratio to the 10/9/8 speed sets. Specifically more cable movement for a 'click' on the indexing. So 11 speed mechs are built around a different rate of cable movement, which makes them incompatible with the earlier 10 and lower gear.
Not sure that really tallies with your symptoms tho.. Would be a good idea to be sure exactly what the mech is. If it's from a (8?)/9/10 speed groups you're good, 11 speed, no..
However, I believe the 11 speed groupsets use a different cable pull ratio to the 10/9/8 speed sets. Specifically more cable movement for a 'click' on the indexing. So 11 speed mechs are built around a different rate of cable movement, which makes them incompatible with the earlier 10 and lower gear.
Not sure that really tallies with your symptoms tho.. Would be a good idea to be sure exactly what the mech is. If it's from a (8?)/9/10 speed groups you're good, 11 speed, no..
Matt_N said:
As above, different actuation ratio on the 11 speed stuff of 1.4 vs 1.7, meaning indexing with your existing shifters and the rear mech won't work properly.
I am also not 100% certain but as 11 speed uses a narrower chain, achieved with narrower outer link plates, the jockey wheels and spacing is narrower, so your 9 speed chain may not run through properly.
Thanks for the quick replies! I will double check the version but looks like I may be staying with the sora mech, or use it as an excuse to upgrade the lot I am also not 100% certain but as 11 speed uses a narrower chain, achieved with narrower outer link plates, the jockey wheels and spacing is narrower, so your 9 speed chain may not run through properly.
Cheers
I know its been a while but thought I would update, the 105 mech was an 11-speed so I stripped the sora mech down and gave it a good clean and I also fitted new cables. It is shifting much better than ever now so thanks for the advice. I have also used it as an excuse to upgrade and just taken delivery of a caad 8 tiagra, not much of an upgrade but it will do for now.
Edited by Mr-captain on Wednesday 15th June 12:47
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