cpeters said:I don't think they changed the group. On the specialized website they advertise the allez as being a nine speed. and i did get a good deal for the bike.
another question. Everything on the bike is 9spd (chain, cassette, shifters) except the rear derailleur which is a 10speed. Why would this be or is it just a number?
As I understand it, there will be no functional difference between a 10 speed rear der. and a 9 speed. The shifting is actually controlled by the speed shifter, in your case, 9 speed.
The der. itself doesn't have indexed spots to move into - it can just move smoothly over a range and the range is determined by the high and low stops. The stops can be adjusted to stop the der. anywhere (in reason). Those stops are determined by the range of movement needed from the smallest cog to the largest. Both the 9 speed and 10 speed rear derailleurs have adequate range for your 9 speed cassette (I believe both would also have adequate range for a 10 speed cassette too). Therefore both will work if controlled by a shifter that is matched to the # of cogs on your cassette.
Where the der. actually stops when you shift is controlled by the shifters and how they move the cables. That's all the derailler "knows". If it's a 9 speed shifter, the inner workings of the shifter move the cable - and der. - exactly the right amount to match with the space betweenn each cog on a 9 speed cassette. That movemet would be the same whether the der. is labeled "9" or "10".
I also believe that if it's a 10 speed shifter, it would move the rear der. the correct amout whether the der. was "9" or "10".