sprockets

[Mr Swivs]

if i reduce my wheel sizes to 17 inch diameter rims, what sprocket sizes should i use to keep gear ratios the same as original please

 

[amc49]

Often the tire comes up in size to pretty much compensate to be close. What size chain, 530 or 630? You don't mention which engine or model either, more than one and all geared slightly differently.

Simple enough to measure rollout on the two to calculate the small difference.

Speedo will change if you change the fronts, harder to make right in many cases.