How to reduce pedaling resistance I brought my hybrid bike to Evans Cycles recently to get the rear gear mech replaced after I broke it. 

When I got the bike back, it was significantly harder to pedal. I tried moving my gears lower but even then the amount of effort required to maintain the bikes speed is higher than before, considerably, which is making my commute exhausting which it never was before. 

I notice that it is harder to change the gears now on my bike - twisting the handle feels harder and the gears move very snappy. Could it be they have over tightened something? What do you think it could be? 

Thanks!
I think the problem is with the bottom bracket. Sometimes, when the crank arms are removed, they can be put back really badly, thus causing the pedaling system to be very hard. Or some other times it's just the bottom bracket that needs to be replaced. Once I replaced my bottom bracket, the pedaling system was better than ever!