From: praetzel@maxwell.uwaterloo.ca (Eric Praetzel)
Subject: Shimano 7 spd vs 8 spd HG hubs - test results on my Klein
Organization: University of Waterloo
Date: Wed, 30 Dec 1992 16:56:57 GMT

Since I was a little bored I thought that I would swap some wheels and
see what worked.
  Testbed:  '90 Klein Quantum with 7 speed Ultegra HG drivetrain (13-21)
  Test:  I just threw in a test wheel and noted what I had to do to
	 make it work.

105 HG 7 speed (training wheel) (13-23)
  - the derailleur needs to be adjusted to get the indexing working

Dura Ace 8 spd HG  (12-21)
  - The interior limit screw had to be backed off to get into the 7th
    gear.
  - Shifting thru all higher 7 gears was flawless
  - Shifting into the 8th gear can only be done with readjusting the 
     limit screw a lot
  - With the oversized chainstays the chain is very close to hitting the
     chainstay while in the 12t
  - This wheel has a 1.8 mm washer on the freehub side.  This made it harder
    to put the wheel on and also made the axle slightly wider than the 7sp
    or 8 spd Ultegra.  I had to pull the frame a bit to get the wheel to 
    slide in.  Of course the extra wide imitation Campy QR nut did not slide
    on as easily as a normal QR.

Ultegra 8 spd HG (12-21)
  - Drop and ride.  The wheel went in easily and no adjustments were needed
    to get the higher 7 gears working.
  - No spreading of the chainstays was necessary.

Summary:
  1) So much for fixed axle lengths.  It seems that the DA axle is about 1mm
     wider than the Ultegra.
  2) The Ultegra axle was a very easy upgrade because it fit in easily, worked
     without one adjustment.
  3) Both 8 speed wheels where not dished properly.  One was bought in a 
     Canadian shop and the other was picked up in the USA.  Both were offset
     by 2mm (4mm total difference) from centre towards the hub.  It seems that
     they are both dished more than they have to be.  The obivous sign was teh
     very lax spokes opposite the freehub.
  4) Both 8 speed wheels were built with 14 ga spokes (Matrix ISO C-II and 
     Omega Strada) and are considerably heavier than any of my 7 speed wheels.
     If you are going for light weight then go get an old 6 speed freewheel
     for those special uphill events.  Weights are:
       7 spd HG 13-21: 240g
       7 spd HG 13-23: 280g
       8 spd HG 12-21: aprox 290g
       6 spd    12-20: aprox 200g (just cogs no body)
     The 14 ga spokes are overkill and 15/16 would save about 70g / wheel.
  5) Oversized Al frames are not a problem when upgrading to these slightly
      wider hubs.
  6) Changing from a 7 spd to an 8 spd wheel will work but you will not have
      the lowest gear unless you adjust the derailleur limit screws.
  7) Don't trust shops to build you wheels properly.  I have also had to
      redish _all_ of the wheels from one friend because they were not dished
      at all.  It seems that quite a few shops get cheap on rear wheels and
      use the same sized spokes on both sides.

- Eric 
// There are now 1/4 of a billion Americans.  One thousandth of one percent
//  is 2,500 people.  With these numbers our society cannot help but have
//  every statistical anomaly.  Why should we be shocked when we see aberrant
//  behavior in the news?  The probability of any one person doing that is
//  extreamly low but the probability of someone doing it is very high.  A
//  one-thousandth-of-one-percent chance that something bad will happen seems
//  minuscule - until you realize that 2,500 real persons will be effected.
//  One of those could be you. Or worse, me.  But we should not be surprised.
//     Jeffrey G. Liss