9 spd vs. 10 spd rear deraileur

[marshace]

At the risk of sounding ignorant and/or stupid:

 

What is the difference between a 9 speed and 10 speed rear derailleur ?

 

When I set mine up, I set top and bottom limit screws, connect cable and set tension so it runs smoothly between gears.

The difference between a 9 and 10 speed chain and cluster, as far as I can tell,  is the spacing between the rings and thus the width of the chain.

The increments of movement of the derailleur, which is different for 9 and 10 speed because of the above, is surely determined by the "clicks" of the shifter and the amount of cable it adjusts (pulls or releases) with each click. 

Top and bottom limits are fixed and the derailleur moves up or down by these increments, the one just has 9 positions and the other has 10.

 

So, to conclude, what stops me from upgrading from 9 to 10 speed using existing derailleur with new 10 spd shifter, chain and cassette ??

 

Just asking ??? 

My LBS will gladly sell me a new derailleur but that's not the point.

 

EM

 

 

 

[droo]

The cable pull ratios are different. 9 and 10 speed are not compatible.

[marshace]

Thx STOKE

 

Is the "pull ratio" determined by the shifter or the deraileur or both ? 

Your answer suggest both, asssume they designed to work together.

[droo]

Correct. The shifter and RD are designed to work together.

[raptor-22]

At the risk of sounding ignorant and/or stupid:

 

What is the difference between a 9 speed and 10 speed rear derailleur ?

 

When I set mine up, I set top and bottom limit screws, connect cable and set tension so it runs smoothly between gears.

The difference between a 9 and 10 speed chain and cluster, as far as I can tell,  is the spacing between the rings and thus the width of the chain.

The increments of movement of the derailleur, which is different for 9 and 10 speed because of the above, is surely determined by the "clicks" of the shifter and the amount of cable it adjusts (pulls or releases) with each click. 

Top and bottom limits are fixed and the derailleur moves up or down by these increments, the one just has 9 positions and the other has 10.

 

So, to conclude, what stops me from upgrading from 9 to 10 speed using existing derailleur with new 10 spd shifter, chain and cassette ??

 

Just asking ??? 

My LBS will gladly sell me a new derailleur but that's not the point.

 

EM

 

 

Is this for road or MTB?

 

For road the 9speed rear derailleur will work with 10speed shifters.

 

ForMTB, .....refer to Droo's responses above

[Goosebay]

SRAM 9sp shifter and Shimano 10sp derailleur has a similar pull ratio.  And a very good shift action.

 

You will need to add a shim - some suggest 6mm (I run 10mm) added to where the cable attaches to the derailleur.

[raptor-22]

SRAM 9sp shifter and Shimano 10sp derailleur has a similar pull ratio.  And a very good shift action.

 

You will need to add a shim - some suggest 6mm (I run 10mm) added to where the cable attaches to the derailleur.

 

 

yes but this won't give you a 10s system

[marshace]

Is this for road or MTB?

 

For road the 9speed rear derailleur will work with 10speed shifters.

 

ForMTB, .....refer to Droo's responses above

Thx, was for mtb.

[marshace]

yes but this won't give you a 10s system

Agreed, was thinking of going the other way round.

[Tankman]

Thx STOKE

 

Is the "pull ratio" determined by the shifter or the deraileur or both ? 

Your answer suggest both, asssume they designed to work together.

 

Pull ratio is determined by the shifter but it doesnt end there ...

 

Shimano works on a 2:1 ratio and Sram on a 1:1 ratio.

(Shimano calls it 2:1 but the actual numbers are different

 

The actuation between deraileur differ.  That is the rate at which the deraileur moves with one shift.  There is a difference in the cage length between 9 and 10 speed.  Probably not a visible difference if you just stare at it but the effect is magnified at the deraileur.

 

So yes the shifter and deraileur are meant to work together.

 

Maybe this might explain it better: