Ask a Mechanic | Indexed Headsets & ISIS/Howitzer Crank Compatibility Ask a Mechanic | Indexed Headsets & ISIS/Howitzer Crank Compatibility Daniel2014-03-05T16:04:55-08:00 Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers Ask a Mechanic | Indexed Headsets & ISIS/Howitzer Crank CompatibilityDaniel2014-03-05T16:04:55-08:00