Hello,

Does anyone know what the dimensions for the ww2 welbikes were?
I've seen it listed as 52" overall length and wheelbase at 39 and 1/2 inch. With tires listed as 12 and 1/2" by 2 and 1/4".
Also managed to find an excelsior maintenance manual that lists the same specs.
Am I right in assuming that wheelbase is the distance between the center of the 2 axles?

In anycase, when I compare these against side profile photos of welbikes, they always come out shorter than the listed length. (I scale the photos based on the tire diameter at 12 and 1/2")

It's quite perplexing.

cheers,
Sonny

Wheelbase is the distance between axle centers.

How do you measure the tire diameter ? I think (someone will probably correct me ...) that the 12 & a half inches is the inner diameter of the tire, i.e. the outer diameter of the rim (the painted part of the wheel) that the tire is mounted on. If you have a bicycle with tire dimensions given in inches you could try and find the measurement that actually fits your tires ?
The outer diameter of the wheel (the surface that touches the ground) is 12,5 inches + one of the other masurements.
/ Robin

The Excelsior welbike maintenance manual lists the tyres as havbing the size: 12 1/2" x 2 1/4" so I am assuming the outer diameter of the tire is 12 1/2"

Looking at it now, you are right that this figure should be the diameter of the wheel rim.

I did a rescale of the photo with this and it now overshoots the listed length of 52"

just to confirm that tyre sizes are always specified by the diameter of the rim and the width of the rim at the bead rather than by the outside diameter of the tyre. Conventions seem to differ about which figure comes first though.

For instance jeep tyres are 6.00 x 16

How much does it overshoot ?
See the other post above about the "bead" When you replace a tire on a bicycle (or other wheel) you need to use a certain amount of force since the rim has a slightly larger diameter than the opening in the tire, they must overlap since otherwise the tire will fall off ...
/ Robin

Additional complication:
I assume that you have seen this drawing:
http://home.earthlink.net/~flyboyken/sitebuildercontent/sitebuilderfiles/welbike.pdf
from this website:
http://home.earthlink.net/~flyboyken/id28.html

In the drawing it says that the maximum wheelbase is 39.5 inches but that is probably the extreme rear position for the rear wheel when the drive chain is really tight (or has become loose due to usage)

/ Robin

Quite significant overshoot. I'll post photos tomorrow.

here's what i'm seeing

hmmmm .... I can't explain such significant differences ...
Are you certain that the photo actually shows a Welbike? The site (some Welbike-owner) mentioned that there was another similar type of scooter (Corgi ??) ... Could the photo have become distorted by being scaled differently in height and width ???
/ Robin

hmm, I've used multiple sources and all have similar results.

As far as I can tell is the corgi had a different tank and steering bar configuration.


As you can see, I've also included the drawing from the pdf you gave me. It's also different. A real head scratcher.

Anyone have the tristar or dragon or a real one to do measurements?