What A Common Wheelbase For A Boardtrack Racer

marair23

New Member
Hi, I'd just like to know when your stretching your frames, what wheel base are you guys using??? Thanks for your help! -marair23
 
Hello Marair23, I did a couple of "stretched" bikes a few years ago. But, some things can get kind of goofy when working with bicycle frames and at the point I had done this one in a traditional "chopper" style 6" out and 5" up I was seeing that. This bike is very long, the forks are 43".

The red bike with the Chinese 2-stroke was the last of that sort I did. This pic was resized in November of 2004, Chinese under frame tank, ladies cruiser I made the sprocket from a bicycle sprocket (much more "round", I have a few of those left 44 teeth, tho they are not drilled with the large lightning holes.) This bike is stock Cruiser wheelbase. I am currently looking to do another bike, and may re-cut this one to be a different animal.

It was now becoming clear to me that I needed to build a frame that had all the details I needed. Wide drop-outs for sheave (or sprocket), man-sized between the saddle and bars, and traditional in it's design. More than enough room in the "engine compartment" was also in order.

In the process, I had some problems with rake, and other details. AFTER I had designed, and done two "do overs" and was riding the first Prototype bike, I got a chance to do what I needed to do first which was to measure an original bike.

The wheelbase (axle to axle) on this blue Original 1910 Excelsior measured about 53". Having the information I now have, I will use as many original dimensions that I can.

This Red Racer is a little short on rake, and might be an inch taller than it could be, however it is close.


I hope some of this helps you,

Mike
 

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Thanks Mike for the info! I'll put it to good use. Is 53 inches common for the wheelbases or did just the builder of the blue one use that? Any others out there have some opinions? -marair23.shft.
 
Sorry, dmar836,
Didn't mean any offence, Your a senior member and I'm new to this I was just asking a question. -marair23
 
Sorry 'bout that. I'm not really a "senior member" as I don't even own a Chinese 2-stroke bike - never have. I just like the older-style motorcycles.
Excelsior was a pretty big interest back in the 191Xs next to Harley and Indian. Guess I thought every one should have heard of them.
That 53" wheelbase is for a full-sized production motorcycle of the day.
You can assume most used 28" wheels(some had 26"). Since 26" wheels are commonly available now, you can resize accordingly giving roughly a 92% scale.
.929 X 53" = 49 1/4" wheelbase to give you the proportional sized frame for a 26" wheel bike.
JMO,
Dave
 
Hi Guys, that Excelsior is a fine "Barn Bike" runs well, and was entered in the Antique Motorcycle Club of America's Concourse D' Elegance a couple of years ago. This one is a 26" wheel model, and yes in 1910 Harley also offered the bikes with 26x2.125 or 28x3. Many pics and the movies I have seen of early board track bikes were the 26, not the heavier 28's.

I have a bunch of other pics of fine Veteran Motorcycle I took that year, and a couple of other years. The reason I showed that "X" is because that was the first one I measured.

Excelsior won many races, and awards for the period of time they were involved in Board Track, Cross Country )an early open-road racing type, and even Hill Climbs. In the day, the Mighty X was often the one to try to beat.

The blue Sears is an outstanding bike, about 1909, again the 26" wheels, and a strange articulated frame.

The red 8 Valve racer is a 1915 "Harley Eater" it was an amazing frightening over 100 MPH motorcycle.

Mike

Mike
 

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i just noticed the exhausts on that indian. i wonder if asbestos pants were needed to ride that.
 
After some heavy number crunching, technical drawings, and just printing out a fake degree from the Einstien School of Photoshop,rotfl.... I have a guesstimate of what the average Board Track Racer wheelbase is, 50-55 inches. Sorry I Photoshopped over such a nice picture. If most bikes of that era had an average of 1" diameter for the frame constuction, this is what I came up with for this bike. 51-52 inches plus or minus. Just an added note: I did the Blue Excelsior the same way after I posted this and it measured out to be 53" right on the money.
 

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WOW! THANKS! This helps me ALOT! Thanks Guys!!!!! - marair23
If I can be so bold to ask another question or 2 ? At 49-55 inches, where are the stress points on a frame that is stretched? And what are your suggestions for reinforcing those stress points when making a bike frame longer? -Thanks
 
i just noticed the exhausts on that indian. i wonder if asbestos pants were needed to ride that.

No they didnt wear asbestos pants but those boardtrack racers were total bad ...I guess to numb the pain they would gulp a glass of mercury and chew lead based gum before every race !!!
 
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Butch, Yes, I think mine is about 55" and too long really.
BTR, Some of the frame tubes were 1 1/8" I think the down tube might have been one of them while the top tubes were often 1". I need to reread my literature though to be sure.
Dana,
You will get all sorts of weird advice. There is no reason a frame made of heavier wall (.8 - .120) mild steel should have any weak spots just from "stretching" it. However stretching a found thinwall bicycle frame and stretching that may likely produce a frame with weaknesses. There were gusseted areas and Don John's Cyclone had diagonal tubes brazed front and back to the down tube and seat tube.
Someone recently said your welds are the weakest points - nonsense! Any welder or reader of simple welding books will tell you that the welds should be the last to fail(if done properly). There are HAZ (heat affected zones) from the heat required to weld but they are typically several inches from the welds. Often, the test for a practice weld is to hammer on the part until failure. That failure should NOT occur at the weld!
Motorcycles back then, despite the similarity in appearance to bicycles, were actually different creatures having thicker (or even internally supported) tubes and cast iron lugs brazed together.
Dave
KC
 
Thanks Dave! Great info. I've been collecting my parts and I'm just about ready to start my project.
Thanks again - marair23 - Dana
 
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