I just bought the Speedplay Frogs for my mid-70's Bob Jackson road bike. Tried to install them yesterday but the pedal thread size on the Stronglight crank arms (made in France) is smaller than the Speedplays. Short of buying new crank arms, is there anything I can do? I knew I should've bought a new bike and not an older bike. But I just love hand-made frames made from Reynolds 531. Oh well.