Gearing down

How many teeth should gain/ lose? I'm thinking one down in the front for 15/48 or two up in the back for 16/50. The other question is aluminum sprockets and how long they last, under hard use. Anyone?

I would start out with 2 up on the back, and then order 1 down on the front if you decide its not geared down far enough yet. you can feel the difference from 2 teeth in the rear, but its not all that much of change.

Forgive my naivety, but I thought most people go down in the front rather than up in the back even though it creates essentially the same effect. Maybe it's just a Pittsburgh thing or something. :confused: I still don't know everything about bikes, though, so feel free to color me stupid.

I'm not sure if its true, but my reasoning is that there is less pressure on the front sprocket if it has more teeth. I'm the color blue btw, what are you?

Well RK sells a 520 covnertion kit with the 15/48. I ran the different gear ratios...
stock 16/48 3:1
front 15/48 3.2:1
rear 16/50 3.13:1
both 15/50 3.33:1

I did it. I just ordered it to today.

RK 520 XW-ring chain, Gold 116 links
AFAM Sprockets 15/49 (So one down in front, one up in back)

I'll let you know how it works out.