Front wheel clamping systems


         Having owned a fair number of bikes over the last 40 odd years, it struck me recently, that there are quite a number of ways of holding the front wheel in a secure position.  It came to a head when I was modifying a rig which I had made to pull a bike along by it's front wheel spindle.

    If I go back to the bike in question on this trip of about 500 miles, (my 1964 Honda CB77) the spindle goes through a plain hole in the left hand fork bottom and is nipped in place by a single pinch bolt.  The spindle then passes through the speedo drive, the hub bearings and then the brake plate, before going through a plain hole in the right fork bottom.  There is then a castellated nut threaded onto the spindle, which is drilled for a split pin.  If that lot gets loose all at once then you MIGHT loose your front wheel!

    In contrast, the system adopted in the next decade by Honda was a spindle through the bearings employing a bobbin type sleeve threaded on to one one.  This could be completely assembled before being offered up to the split clamps on the fork bottoms.  The split clamps are tightened to the correct torque, front bolt first, so that all clearance is taken up, followed by the rears, which then act as normal pinch bolts. 

    As a brief note, I have found these on second-hand bikes, with all manner of combinations of incorrect fitting methods - split clamps the wrong way round, rear bolts tightened first, thus bending the bolts.  One clever chap had even decided that he didn't think that gap was correct - so he made a couple of shims to fill it!  Read the bloody manual, or leave it alone you moron!

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