I recently bought a Specialized Sirrus Expert. It's a great road bike, but I am having a problem shifting from the large chainring down to the middle chainring. It just hangs up and doesn't want to push the chain over. There is no problem going the other way. It is a Shimano Deore 31.8 bottom pull. I seem to remember a previous post saying that you had to shift all the way down to the smallest chainring and then back up to the middle one. Is this true??? The bike is only two months old and the bike shop where I bought it says it is adjusted correctly. But even when I am riding on level ground it still doesn't want to shift. I can pedal a couple of revolutions and the bike stays in the largest chainring more than half the time. The bike store said to take pressure off of the pedals to let it shift (doesn't help). My friend says to hold the shift lever longer (didn't help). Forget about trying to shift when going uphill. The derailleur appears to be positioned so the chain is in the middle, not leaning to one side or the other. My previous Trek mountain bike didn't have this problem. Shift levers are Shimano R-440 8-speed rapid fire, chainring is a Specialized 52/42/30. The rear derailleur is a Shimano Tiagra. Is there a better front derailleur that I can upgrade to? Do they make a Shimano Tiagra front derailleur and would it work better? The bike is a 24-speed bike. This is driving me nuts!