Results 1 to 6 of 6

Thread: R75/5 Wheelbase

  1. #1
    Registered User bluehole's Avatar
    Join Date
    Oct 2005
    Location
    Midlothian, Virginia
    Posts
    599

    R75/5 Wheelbase

    I am not as familiar with airheads as I should be. I understand there is a short and long wheelbase on the 75/5. What is the deal? Is one more desireable than the other? How can one tell the short from the long wheelbase? Is it visually obvious? Huge learning curve ahead of me.

  2. #2
    Administrator 20774's Avatar
    Join Date
    Sep 2005
    Location
    San Antonio, TX
    Posts
    13,237
    Didn't the switch happen in the mid 1973 year models? Fiche info shows the part number for the swingarm changed after 2/1973.

    Short wheelbase - due to "short" driveshaft tube; it also has the smallish battery.

    Long wheelbase - you should see about a 2-3" plug welded into the driveshaft tube; with the added space, the battery could be bigger.

    I think the biggest difference is in terms of handling. The short wheelbase can be more "flickable" but some have indicated they might be unstable at high speed. I think the instability is more a function of proper set up (bearings, shocks, tire pressure, cargo loads, etc.).

    Matt Parkhouse has been doing articles recently in the MOA News about his experiences with various /5s that he owns or has resurrected. His first bike, that he still owns, was a SWB but if I read correctly in his recent article, he grafted a LWB swingarm on at some point.

    Kurt in S.A.
    Last edited by 20774; 10-17-2006 at 02:11 PM.

  3. #3
    advrider.com
    Join Date
    Oct 2005
    Posts
    3,192
    I think up 'til 74 the LWB conversions were obvious. A 2" welded tube added to the driveshaft tube, where it meets the rear. After a while, it was just one solid piece the same length, but with no visible weld.

    So, the quickest way to check if you're not sure is to look at the driveshaft tube. If it does a quick taper close to the end, it's a SWB. If there is a taper then a 2" section that is not tapered, it's a LWB (whether it's welded or not).

    Hope this makes sense.

  4. #4
    James.A
    Guest
    Quote Originally Posted by 20774
    Didn't the switch happen in the mid 1973 year models? Fiche info shows the part number for the swingarm changed after 2/1973..
    I own an original R75/5 purchased from the original owner in 1989. It is a LWB, with a date stamp on the steering head I.D. plate of 11/72.

  5. #5
    Administrator 20774's Avatar
    Join Date
    Sep 2005
    Location
    San Antonio, TX
    Posts
    13,237
    Quote Originally Posted by woodnsteel
    I own an original R75/5 purchased from the original owner in 1989. It is a LWB, with a date stamp on the steering head I.D. plate of 11/72.
    I'm guessing it means that the SWB part was no longer available after 2/73. It's quite possible that the LWB parts became available earlier and the two parts were used on the assembly line until the SWB parts were gone.

    Kurt in S.A.

  6. #6
    K Bikes Complex by Choice cjack's Avatar
    Join Date
    Apr 2003
    Location
    Urbana, IL
    Posts
    3,710
    Quote Originally Posted by 20774
    I'm guessing it means that the SWB part was no longer available after 2/73. It's quite possible that the LWB parts became available earlier and the two parts were used on the assembly line until the SWB parts were gone.

    Kurt in S.A.
    It doesn't reflect the availability of parts on the fiche. There is sometimes a code referring to the obsolesence though. The fiche thinks that the wheelbase (part) was changed in 2/73.
    Many SWB bikes were made into LWB bikes after when the parts became available and was a pretty simple update. Not saying that is true for woodinsteel's but it was pretty common.
    BMWMotorcycles, fun when they're running...
    My other bike is a BMW.
    Jack Hawley MOA and RA #224, KE9UW ("Chuck")

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •