corwin1968 is correct on his analysis on why MTBers use wider bars. I have since converted my DS 8.4 back to just road use and the wider 75cm bars/7cm stem just isn't practical for road use. PERIOD. Aerodynamics, body positioning, cornering just doesn't translate technique when applying to the road when using MTB techniques. So, after all the mods i did to the DS 8.4 to get it to handle awesome on teh dirt, it is back to a longer stem, super narrow bars(60cm).