I am looking for a 4" gauge mount and it would seem that some of the HD models have 4" gauges. I high sided in the rain on a downhill curve last year here in Germany. I am swapping out my damaged tank on my VT750 for VTX 1800 tank, smoothing and filling the top, and installing a pop up cap. In doing so, I am replacing the stock 5" speedo with a 4" GPS speedo/tach combo made by Speedhut.
http://www.speedhut.com/customizer.i?clid=669659

Therefore, I am looking for knowledgeable folks on here to who might know which models have a chrome 4" bar mount with cup. I have found very little on the Internet that gives actual measurements of gauges. I need the inside dimension of the cup to be at least 3.875". Can anyone help me out?

 

You can try a Road King Tach handlebar mount or the Sportsters have a 4" speedo mount on the handlebars I'm sure both are available in chrome. I have seen them on ebay aso or you could pay full price from your local HD.