Promise yourself an Ultegra upgrade with the money you save by laying off the cigs.
Don't promise yourself a whole new bike at the end of the year - upgrade your bike each month, using the money you saved that month by not smoking. Just take it one month at a time, and keep those upgrades going. Don't look at it as quitting for ever - quit one day at a time. That's how I did it (without the bike incentive though).