10 Speed 105 shifters with 9 speed casette

[Joffey]

I don't like the gear cables on my 9 speed 105 shifters and would love them under the bar tape but you need the 10 speed 5700 shofters for this. To save cost and not buy a new groupset would the 10 speed shifters work with my currect 9 speed rear derailiur and cassette? Thanks!

 

[oliglynn]

In a word, No. The gap and hence the distance the derailleur has to move between gears is different on 9 and 10 speed, and this not adjustable on the shifters, hence they are not compatible.

 

[Pumpkin the robot]

The 9 speed derailleur will work but not the 9 speed cassette. The derailleur does not decide the pull, that is down to the shifters, so it will work., so you would need shifters and a cassette.

 

[Joffey]

Ah, a cassette wouldn't be too much more expense. Might give that a try then. Thanks!