Whizzer bi-matic 2 speed clutch rebuild

Discussion in 'Whizzer Motorized Bicycles' started by msrfan, Jan 17, 2012.

  1. msrfan

    msrfan New Member

    I recently acquired a bi-matic two speed clutch and have heard the bicycle type bearings are what keeps it from shifting properly due to all the slop they allow. I was wondering if anyone knows the correct replacement bearing numbers. I would like to replace my Whizzer autoclutch with it.




  2. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Msrfan,

    Fantastic looking Whizzer!!!!!!

    This site is the only place to obtain accurate Whizzer information as I no longer visit or contribute to sites that are against the American free enterprize system.

    Here goes.......
    First of all Terry McAllister was the expert on Bi-Matics. Terry and Audrey were good friends of mine and in fact were at my home in NC several months prior to their passing. They dropped off the dual motor Whizzer in the fall of 2010, that I was to run at Bonneville. Terry is the one that talked me into writing the Quenton's Corner for the Whizzer Newsletter [which Terry & Audrey published prior to their passing], and still do so today.

    Of course Terry and I spent a lot of time together at various motorbike shows and events, and often talked about the Bi-Matic. Terry didn't upgrade the bicycle bearings to the automotive type, but developed better gaskets & seals to keep the fluid inside the drive. He also told me he had to often replace the main shaft because of massive wear when the drive lost its fluid.

    Other things we discussed were the many different versions of the Bi-Matic. The versions used on the Sportsman, and Ambassador didn't include any way to start the motor via turning the rear wheel. The Sportsman version also had a larger drive pulley to compensate for the smaller 20" wheel. He also told me there were far more of the Bi-Matics made for the Sportsman and Ambassaodor around than any other version, but he was able to alter the parts [in some cases adding parts] to fit the stock Whizzer motors [no kick starter].

    There is an exploded view of the Bi-Matic in the Whizzer dealer book, and detailed information about servicing the drive. Might be worth the effort to latch onto a copy of the book for more information.

    Currently, I don't know of anyone that rebuilds the 2 speed drive, but hopefully someone will do so in the near future. Who knows I might even look into the process if no one else does.

    Hope this information is of some help.

    Have fun,
  3. msrfan

    msrfan New Member

    Thanks Quenton, it's an older restoration with a couple of upgrades. Roller crank, 5 inch front Whizzer brake, Mikuni carb, automatic clutch, echo pipe, finned aluminum exhaust elbow and point eliminator.
    That's what I needed to know. Sorry to hear of Terry's passing. I'll figure something out. Everything looked okay inside as far as lack of excessive wear. I was surprised how nice the shaft and gears are. Someone has definitely been inside it as I found one of the starting pawls repaired. I paid a lot for it, so I'll keep plugging along until it works. I also heard a full compliment of balls, instead of the caged units, will help keep things aligned and tighter. I've already identified and located the seals in a good brand-name multi-lip spring loaded design.
    Do you still repair the late autoclutches? I think I have a good one to upgrade. The pins are anchored well but the sprag rides on cast iron.
    Thanks again for the response, I'll keep in touch.
  4. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi msrfan,

    I noticed the 5" Whizzer front brake [sure wish I had one] on your great looking Whizzer. I too have the German crank and the eltronic module in all my personal Whizzers. Several of my bikes have the #270 automatic clutch and I really like the way they work, except when the motor hesitates to start, and they kick back. I have bent a couple or the paws because of not starting smoothly.

    I do remember Terry explaining the secret was to use the right thickness of gasket material and the right kind to seal correctly. I rode his OHV several times with the Bi-Matic, and it always reminded me of the old Chrysler "Fliud Drive" transmissions of the late 40s and early 50s, because you had to let off the throttle to allow it to shift. On the ride at Portland last year several of my friends were using the Bi-Matics and had a hard time because of the speed and they kept shifting down. I think we were going too slow [LOL].

    I still upgrade a fair amount of the later clutches, usually a few a week.

    Let me know how the Bi-Matic works out.

    Have fun,
  5. msrfan

    msrfan New Member

    I've cleaned up all the parts to the bimatic clutch and see just how it works. One of the large bearing races is broken and will have to be replaced. A little work on the starting pawls and a few new pieces should get it going. I'll keep you posted.
  6. WZ507

    WZ507 Member

    Whizzer Bimatic Repair/Rebuild


    Terry McAllister's inventory of Bimatic parts went to Ralph Newcomb in MI who repairs and rebuilds Bimatics. I'm sure he can help you out and can be contacted via email at ralphjnewcomb@gmail.com.
  7. msrfan

    msrfan New Member

    Thanks WZ507. That's great info. I'll contact him when I have a parts list.
  8. Hi,
    I found this thread and see it is an old one but I thought I would write, I have the org paperwork on the Whizzer bimatic transmission and helped my Dad rebuild it 23 years ago. I now have it apart for a oil leak that was at the starter paw rivets. Does anyone know the correct inplay that the transmission is suppose to have? The book does not say. We cut a shim & 2 thin gaskets but I can't find what the implay is suppose to be. Thanks!
  9. Jhoover

    Jhoover Guest

    Sorry, I don't have your endplay answer. I'm new to bi-matic's and struggling to find any info. Would you be willing to share a copy of what you have on them? I'm a gear head who rides too and like to work on my own stuff. Any help really appreciated!
  10. Steve O

    Steve O Guest

    Hi Jerry, Sure post your email address. The endplay should be somewhere around .010 +or- . Steve