The only sure way of comparing frames is by comparing their respective stack and reach measurements. In the Pinarello geometry chart, Competitive Cyclist shows the stack and reach measurements for the 2 sizes that you are considering. Specialized did not publish the stack and reach measurements for the SL3. Possibly the data may be available by contacting their Customer Support. SigmaSports in the UK does show stack and reach for the SL3 that they are selling. To be certain of its accuracy, contact Specialized or do the measurements yourself. Leonard Zinn of Velonews has explained how to do it yourself, http://velonews.competitor.com/2012/05/ ... lly_216035
" onclick="window.open(this.href);return false;. If the SigmaSports data is correct, the stack height of your SL3 is closest to the smaller Pinarello but the reach of your SL3 is closest to the larger Pinarello. The larger Pinarello may be the better choice. No stem spacers and possibly a shorter stem (eg. 120 mm) and possibly a -10 degree angle. You may need to experiment in this regard. In the same way that stack and reach can be measured for the frame, a similar measurement can be made for the placement of the handlebars.