Thread: Best 6 speed freewheel: 13-24
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Old 10-10-12 | 07:45 PM
  #42  
tjc9005
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[SIZE=4][SIZE=5]
Originally Posted by Captain Blight
TCJ, did you just buy a regular Shimano Megarange unit and swap the cogs? I had no idea that the bodies still used the same spline pattern. This changes everything.


You have to use the 6 speed version- this specific model only MF HG22
(or MF HG20 which I dont think is currently in production). Note,
there is another Shimano 6 speed in production called MF TZ20. This
has a completely different design and will not work. Some online
sources say they are selling a HG22 but send you the TZ20 (Universal
Cycles did this to me). The 7 speed HGxx models will work as well but the freebody
design is a little different with three step offs instead of just two.

Careful with the Megarange freewheels. A lot of them are the TZxx
models - those will not work. Any Megarange that is HGxx should work.

You do have to make a minor modification to the sprocket's spline
pattern. The modern HG sprockets have a square notch that lines up
with a square spine on its freebody. This keeps the HG sprockets
properly aligned with each other. It was very easy to modify the notch
to match the others with a file. The HG sprockets then slide right onto
the old Dura Ace free body. There is a small reference arow on the
sprockets that can also be used to properly align the sprockets.

Finally, you have to use the threaded Dura Ace sprocket to complete to assembly. One for
the 6 speed and two for the 7 speed. Sounds more confusing than it is.

I have also see onther Shimano freewheel hacks. Here is one
http://blog.harriscyclery.com/custom...ed-freewheels/
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