Author Topic: Motorcycle Oddity  (Read 626 times)

Offline Wheeler

  • Advanced Member
  • ***
  • Posts: 3
  • Karma: +0/-0
    • View Profile
    • Email
Motorcycle Oddity
« on: May 10, 2021, 05:12:52 AM »
Hello People,
When I was a teenager in 1968, I found an old abandoned rolling motorcycle frame leaning against a tree. There was no engine and no identification what so ever - as to what make and year. It was very heavy duty.  There was no gas tank, but it still had a single springy leather seat and handle bars. The mechanical drum brakes worked and the bike had large tires and steel spoked wheels - still held air and had lots of tread. It was all painted black with no chrome. The odd thing about it was the front suspension. Below where the headlight was once mounted, there were two large springs.  Between the springs there were cast iron levers and shives arranged with four consecutive rubber vee belts. This gang of belts were very short and actually bore the weight of the front end, serving as a cushion. It was very heavy, but you could push that bike and coast for a while. I remember running it up over a curb and marveled as it completely absorbed the bump.  As kids do, we got bored with it and abandoned it ourselves.  Well, I'm an old man now and over the years I have searched the internet and read all about the old suspension systems - springer and girder types, etc. I never saw anything with that arrangement of belts.  So, at the risk of boring you, I thought I would write and see if anybody is familiar with this type of setup. I've looked at old Harleys, BMWs, and antique American bikes, but to no avail.  I even looked at old military bikes from the 30's and 40's.  If anybody has ever seen anything like this, I would certainly appreciate your comments.  Thank you very much.

Offline cardan

  • Advanced Member
  • ***
  • Posts: 927
  • Karma: +18/-2
    • View Profile
    • earlymotor.com
    • Email

Offline R

  • Advanced Member
  • ***
  • Posts: 1263
  • Karma: +25/-9
    • View Profile
Re: Motorcycle Oddity
« Reply #2 on: May 11, 2021, 06:24:05 AM »
I can't detect any rubber bands there ?
Or can I ??

Some speedway bikes etc had a pair of rubber bands as front suspension.
https://i.redd.it/bxujs1mka5j31.jpg

I don't know where they got the idea from ?
Its said there is nothing new under the sun, someone will have tried it before ...
« Last Edit: May 11, 2021, 06:25:53 AM by R »

Offline cardan

  • Advanced Member
  • ***
  • Posts: 927
  • Karma: +18/-2
    • View Profile
    • earlymotor.com
    • Email
Re: Motorcycle Oddity
« Reply #3 on: May 11, 2021, 07:32:18 AM »
I can't detect any rubber bands there ?
Or can I ??

Three out of four ends: both models have rubber bands for the rear swing arm (under the saddle), and the 1953 model has bands at the front. Various prototypes and pre-production versions had rubber bands at the front, even though the 1948 model came out with springs. Apparently this suspension was extremely good on Belgian pave (cobbles).

Plenty of other rubber band things: Harley Hummer and Royal Enfield Flying Flea would be common ones, and don't forget the Tandon Kangaroo! Wheeler doesn't say what continent he was on when he spotted the mystery bike.

Leon

« Last Edit: May 11, 2021, 11:33:13 PM by cardan »

Offline cardan

  • Advanced Member
  • ***
  • Posts: 927
  • Karma: +18/-2
    • View Profile
    • earlymotor.com
    • Email
Re: Motorcycle Oddity
« Reply #4 on: May 11, 2021, 11:42:54 PM »
Almost forgot the Excelsior Autobyk - another rubber-band-suspended machine, if not "very heavy duty".

I had a look for prewar rubber-band-suspended machines, but couldn't find many. Maybe the DKWs of the late 1930s - from which the designs for the Harley Hummer and the RE Flying Flea were lifted - were the earliest? It could have been a rubber technology thing, as a snapped band while riding is probably not a nice feeling. Here's a clear view of the 1938 DKW fork.

Leon
« Last Edit: May 11, 2021, 11:46:52 PM by cardan »

Offline cardan

  • Advanced Member
  • ***
  • Posts: 927
  • Karma: +18/-2
    • View Profile
    • earlymotor.com
    • Email
Re: Motorcycle Oddity
« Reply #5 on: May 12, 2021, 12:25:08 AM »
It was very heavy... I've looked at old Harleys, BMWs, and antique American bikes, but to no avail.  I even looked at old military bikes from the 30's and 40's.

In terms of big and heavy, Gnome et Rhone used rubber suspension on their 800AX2 from 1938 - quite a lump.

The rubber rings were called "anneaux Neiman" ("Neiman rings"), and Gnome at Rhone called their suspension "patented" when they introduced it in 1937.

Leon

Offline R

  • Advanced Member
  • ***
  • Posts: 1263
  • Karma: +25/-9
    • View Profile
Re: Motorcycle Oddity
« Reply #6 on: May 12, 2021, 09:59:16 AM »
Nice find.
If you squint a bit - or zoom in - the rubber rings are clearly visible.
https://upload.wikimedia.org/wikipedia/commons/f/fc/Gnome-Rhone_AX_2.JPG

"Wheeler doesn't say what continent he was on when he spotted the mystery bike."

That would be helpful/useful to know ...


Offline cardan

  • Advanced Member
  • ***
  • Posts: 927
  • Karma: +18/-2
    • View Profile
    • earlymotor.com
    • Email
Re: Motorcycle Oddity
« Reply #7 on: May 13, 2021, 02:39:04 AM »
Some speedway bikes etc had a pair of rubber bands as front suspension.
https://i.redd.it/bxujs1mka5j31.jpg

I don't know where they got the idea from ?
Its said there is nothing new under the sun, someone will have tried it before ...

The idea likely originates with one of M. Abram Neiman's early patents, e.g. FR724183 from 1932. See the image attached.

I had a look, but can't see who came up with the bi-directional (compression and rebound) rubber band system used by DKW (first?) then Gnome et Rhone, Excelsior, Royal Enfield, Harley Davidson and so on. I don't think it was Neiman - he had patents for variations of his rubber bands, mostly for cars, but went on to be more interested in anti-theft systems for cars.

It seems that Neiman bands were/are popular as undercarriage suspension for light aircraft.

Cheers

Leon
« Last Edit: May 13, 2021, 02:42:16 AM by cardan »

Offline Wheeler

  • Advanced Member
  • ***
  • Posts: 3
  • Karma: +0/-0
    • View Profile
    • Email
Re: Motorcycle Oddity
« Reply #8 on: May 14, 2021, 07:35:27 AM »
Hello People, 
I was very impressed and grateful for your prompt response to my article.  Thank you ~ This was very helpful.
I'm sorry I neglected to state the location.  The "Motorcycle Oddity" occurred in the USA - Swarthmore, Pennsylvania. Cardan's Gnome et Rhone 800AX2 from 1938  seems to be very similar to what I recall.  To my untrained eye, the belts appeared to be short "vee belts". They were cloth reinforced rubber - not just large rubber bands. The fact that there were several placed side by side served to distribute the weight.  This redundancy eliminated the danger of a sudden failure. I had the impression that there would be visible signs of wear well ahead of failure. It was a very sturdy and reliable design. The demon was in the disassembly required to replace those belts.  Thanks again for all the replies and suggestions ~ Dennis