Click Here to reference Sportster VIN Information in the History section of the Sportsterpedia.

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The 1970-1972 frames were basically the same overall frames.

• 1970-1971 frames were respective to either XLH or XLCH oil tank brackets etc.
• The 1972 frame is universal as it has provisions for both XLH and XLCH models.
  • The bracket is there for the XLH oil tank on the right seat post but unused for XLCH.
  • The frame has 2 threaded holes under the seat casting for the XLCH oil tank bracket but unused for XLH.
  • The channel on the left seat post has threaded holes in the top and bottom for the each's battery tray.
    (lower only used for XLH, both used for XLCH)

Seat Cast Webbing, Key Switch and Coil Mounting: ¹⁾

• Since 1st electric start on the 67 XLH, the key switch moved under the seat and the coil moved to under the seat also.
  These bikes were fitted with a new 'longer' frame used thru 1972.
  In 1973, the manufacturing changes to the frame had all the key switches on the motor mount and all coils under the tank.
• Key Switch Location:
  • The long frame had a larger web, or wing if you will, on the right side of the frame casting to mount the key switch.
    For the 1972 model year, a strange thing happened with this wing that says something about the earlier years.
• Coil Location:
  • Part# (51526-52) was/is the spring retaining plate for the sprung seats.
    That's why it's a 51xxx number instead of a 31xxx number. In 1967, the coil mounting holes were added and it became part# (51526-52a).
    The long frame rear fenders got a dent made in them for coil clearance.
    Power to the rear brake switch came from the hot side of coil primary terminal.
• This is how all 1967-1969 XLH (long) frames came. XLCH still used the short frame.
• In 1970, the short frame magneto CH was dropped. So the 1970 CH used the long frame with a battery for the 1st time.
  
  • All 1970 models had underseat mountings, same as the 67-69 XLH.
• The early 1971's were also like this. It's in mid 1971 that the fun started. That's when the (52019-70) “low” became available on new bikes.
  The low seat interfered with both the old key and coil
  (when you see the older aftermarket seats they have brackets that attach to the fender rail/frame mount bolts holding the seat up off the coil and key)
• If your bike came from the factory in 1971 with a low seat, it got the key moved to motor mount and a coil moved to under the tank.
  But to do that other things had to be changed.
  • Key Switch: In order to fit on the motor mount, the horn mounting needed to be changed since the back side of the switch would hit it.
    So all 3 pieces to the horn mount were changed to accommodate.
  • Coil: The 1st under tank coil brackets were not 2 pc bracket and plate affairs. That started in mid 1972.
    The 71 style coil mount was 1 pc with the plate being integral with the mount. And they were longer.
    It held the coil closer to the front rocker box.
    While searching for the 1971 mount,
    Be aware that some people hacked them into 2 pcs because the 1 pc was notorious for not being able to keep coil tight during operation.
    Power to the rear brake switch now came from the I terminal of the key switch.
• The low seat kit (52020-71) had a couple different configurations of this kit having the same part number.
  • The earliest had the seat and brackets, the new coil mount.
    In this one you were instructed to move the key forward and to the bottom side of frame web by using the old forward mount hole as the new rear one.
    Then drill the new front one. This worked out ok for the XLCH but was a bit tight for the XLH.
    You were to extend the brake wire and attach it to the I terminal of the switch.
  • The later kit had all the bells and whistles for complete conversions moving the key to the motor mount and the coil to the tank.
    Horn mounts and wiring was supplied.
• 1972 Model Year:
  • This is the last year for the standard seats and the bikes that had them came with the old mounting positions.
    The low seat bikes came with the later mounting positions.
  • Remember the 1972 frame web comment from earlier. The 1972 frame came with all 3 holes on the web for the key switch.
    Even though the factory never used the underhand mounting that was called out in the early low seat kit, it's the only frame that had 3 holes from factory.
    Not every 72 frame may have them, but the ones that did were only 1972 frames.
  • If your bike was a late 1971 or a 1972 with the standard seat, it may have come with any combo of the early and late key/coil positions.
    If you ask any knowledgeable 67-69 restorer,
    They will tell you if you take 3 different original bikes, you may have 3 different setups concerning different parts right from the factory.
    Some of this reappeared in 71/72 model years. Though it most likely retained the earlier stuff.

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