Blue,
I know what crash bars are, I have an old BMW and we avoid them as they often help flip a bike rather than limit damage. I'd rather have a skinned valve cover. I asked him to flush out the questionable "historical data" being offered. I have yet to hear or read about such things on the board tracks, dirt tracks, or concrete speedways - even to this day. His info is random and, in this case, bogus and I wanted to know why he would even say that.
This was what I meant - we got side tracked.
Double,
Tires are not what sets a board track racer replica apart from a "flat black cantilever frame with flipped bars and white walls". Oh and add that HT engine. I appreciate the efforts of anyone wanting to locate of make correct looking tires but there are many, many things that can look "not the part" even if the tires look correct. To get a different look - one that makes people draw closer to see what you have - is to follow the path you are on. Start from scratch rather than using a bicycle frame. We have all used bicycle parts here and there but don't look at a bike frame as your base. You can use the head tube and rear stays if you want but don't let a preexisting pattern(from a bicycle) force you to compromise the shape you are after. Use it only if it fits into your plan. Doing this, you will want to learn some basic bicycle geometry principles like the head tube angle and bottom bracket height. Grafting in a bike with top and down tube still attached can cause you to alter these critical dimensions. It's not difficult to learn so keep it in mind.
Do you have a bike you want to replicate? That's where to start. That's your plan. You can like the aspects of many but you really need to settle on a particular one.
This is a great site but I can seldom get it to link. This will give you an idea of the best pic to start with.
After than, print a side view and draw a 1" grid over it. Using this you can estimate, assuming it had 28" wheels, what you would need to do to every other critical measurement you take from the pic. More on that later. Remember there is distortion in most every photo(my wheels were different sizes in the my pic).
Here, I was checking some angles with an overlay but the grid is still visible on the pic(BTR did a much nicer job of this on his project).
Since the 28" wheel size on mine was the only known factor, I started there. 26/28 = .92857 (1:.92 scale or 92.8 % of the original). Most of that is just to let yourself know what scale you are in.
Now about the grid. Pretend you are now looking at a pic of a 26" wheels BTR - the proportions will be identical regardless of size. Get some $15 digital calipers from HF. Start by accurately measuring the wheel diameter. Since you applied a 1" grid, jot down the measurement of the wheel. Mine was 2.961". So that's 2.961" for a part that has a 26" span. 26/2.961 = 8.78. This is the MAGIC NUMBER. You will use it to scale up your frame from the drawing. Any measurement you take(in inches) will be multiplied by 8.78 to come up with a real size in .92 scale.
I used calipers to measure head tube and other tube lengths, bottom bracket height, wheelbase, etc. Every measurement must be multiplied 8.87. If the head tube to seat tube was 3.5" in the pic, then that's 31.045" in my scale size.
You can use these numbers to build a full sized plan on cardboard. This will give you a visual check to see if things look right.
You can see how using a set tube length from a bicycle will throw the appearance and plan off very quickly.
Did I confuse you? At least we are back on topic.
Dave
KC
but i need your guys help and advice first
