My road bike has a Campagnolo Veloce gearset. It's running 53 and 39 tooth chainrings. I have a 13-25 10sp cassette.
I find that a lot of the time when I'm cruising, I'm on the big chainring and in the 3rd or 4th largest gears on the back. There is a fairly significant chain angle. Because of this, the chain is a bit noisy and I'm sure it's stressing the drivetrain a little. Also, when I need to drop down a gear I quickly need to drop onto the small chainring which necessitates significant adjustments on the rear.
I'm thinking of changing the 53 chainring to a 50t. I am happy to lose a little top end speed.
According to my theory, dropping a 53t to a 50t will reduce my gear ratio by 1.06 (53/50). Which would be the equivalent of switching from a 17t on the back to an 18t. Assuming this is correct, it's not going to have a very big impact, but it might be enough to make it worthwhile.
I know there is an option of using a 3 chainring crankset, but I think that will be a bit too expensive and still won't solve the core issue of getting the right sized large chainring.
The other option is to change the cassette but I can't see many that would really make much of a difference. If I could get a 15-25 that'd probably be about right.
My questions are:
- Will the change mean I need to change or adjust the front derailler, the rear derailler or the chain?
- Will there be any other impacts I haven't thought of?
- Any other ideas to solve the problem?
EDIT: I can't seem to find a 135mm BCD 50t chainring. I asked my LBS and they said no go. ChainreactionCycles don't have the combination I want. Can I get a 50t 135mm BCD campag chainring? If not, what can I use as an alternative?
EDIT: I've found that BBB make a campag compatible chainring that looks like a good option
EDIT: As indicated here the BBB chainring doesn't fit. Looks like a proper compact crankset is my only option now.