It's all based on the tire diameter, not the wheel diameter.
Generally, tires mounted to 18" rims are a bit wider than those mounted to 19" rims.
The Vulcan 900 Custom runs a 21" wheel, the Classic runs a 16", but both the 130/90-16 and 80/90-21 are within 5%.
If you have changed your rim and are no longer running a tire that is the stock diameter, then there's no way to readjust that speedo, short of finding a hub drive unit that'll fit your rim, but came from a bike that uses the same size tire you are using now.
__________________
- Rich
2006 1600 Ultra-Classic
Patriot Guard Rider
Please put your bike year/model in your sig line or fill in your profile before asking for help.
|