If I set up a bike with:
- 10-speed tiagra shifters
- 10-speed dura ace read derailleur
- 9-speed 105 front derailleur
Will it cause problems if I use components from different series? (All of these are from within the past year or two.)
If I set up a bike with:
Will it cause problems if I use components from different series? (All of these are from within the past year or two.)
Your best performance will come from using components which were designed to work together, i.e. with the complete drive train from the same year and series. That doesn't mean that different combinations will not work together at all, however.
While I have occasionally used a 9 speed front derailleur with a 10 speed drivetrain as an emergency fix, it shouldn't be used for a permanent set up. Your shifting performance will suffer, even if they are both double or both triple components.
In addition, the year and model of the Dura Ace components matters. The 7900 STI levers, which are current Dura Ace, have compatibility issues with the 7800 front derailleur of just 2 years ago, even though Shimano says they are fully compatible.
I've added scans of the Shimano 2012 Compatibility charts for front and rear drive train components. You will notice that no 9 speed part is listed as compatible with any 10 speed part, but that even the new 4600 Tiagra 10-speed is listed as compatible with all 10 speed components.
I hope that helps.
Shimano Front Derailleur Compatibility Chart

Shimano Rear Derailleur Compatibility Chart

Yes, you can mix components from different series (you see many bikes with a mix of component level).
BUT, you cannot mix 9/10 speed, do not use a 10 speed sti shifter with 9 speed derailleur. Additionally, check your front shifter to see if was made for double or triple chainring and make sure your front derailleur will work with the number of chain rings you are going to run.
9 and 10 speed are pretty close in width, so you should be OK to mix 10 speed shifters with a 9 speed frount derailleur ( I have several bikes set up like that ). Just make sure the limit screws are set up correctly so the chain does not fall off. At the rear you need to make sure that cable pull is compatible. I'm not to sure about your situation because Dura-ace has at times used a different cable pull to other shimano derailleurs