compact crank 172.5 9 speed

[paul krige]

Does anybody know for certain whether a 10 speed compact crank will work with a 9 speed system ?I have a Shimano 105 9 speed 172.5 and want to convert to a compact crank 172.5 but Shimano apparantly only make compact cranks in 170 and 175 in 9 speed but they do 172.5 in 10 speed.Anyone know where I can get a 9 speed crank ( in Shimano 105 price bracket )

[Ox_Wagon]

I have a FSA Gossamer compact (175mm) that works fine with 9 or 10 speed.  I currently using with 9 speed shimano and I also have used it with 9 speed campy.    Ox_Wagon2008-06-06 08:35:25

[turtlek]

i have a 170mm FSA SLK carbon crank set used it on my road bike which is ten speed but decided to go hardcore and use it on my MTB which is 9 speed and it actually works perfectly

[linnega]

A crank only has one, two or three "speeds".  6,7,8,9,10 or 11 at the back makes no difference whatsoever.  Your LBS is probably trying to BS you into paying more for the 172.5 "10 speed" crank when in reality all three sizes are the same. 

[paul krige]

what I have been told is that a 10 speed crank will probably work but the gauge of a 10 speed crank is narrower than a 9 speed crank and there could be lateral play in the chain ? Sounds very technical to me but a number of people have said they would not recommend it because of the narrower blades.