sannerbikes700

In my framebuilding workshop we have such a small amount of time to get the frames done that we don't have time to draw them by hand or even in bike cad.

So I put together a calculator in excel (which took me lots of hours of formula work) which instantly spits out all the cut lengths and tooling setup from a frame spec.

A friend put it in HTML and I put it online. It's not quite perfect, and not beautiful, but it work if anybody wants to use it. If you don't need to draw up a frame it will save you loads of time.

You have to click into another cell for the output cells to fill.

https://sannercycles.com/manufacturin...calculator.htm

Assumptions: a couple of fields didn't work, so the formulas assume a 10mm head tube above the top tube and below the down tube. They also assume the seat tube goes above the top tube 3 mm, but its easy to just add the extra you want in your head. AKA the formulas are for your common lugs with 10mm head collars and a stop ring in the seat lug 3mm above the TT. The top tube slope angle assume a slope upward from the TT/ST centerline intersection. Everything is in c-c.

The "Dropout Axle to SS End " and "Dropout Axle to CS End" fields mean the center of the axle to the very end of the chainstay or seat stay tube. The seat stay calculation assumes a straight seat stay, traditionally brazed onto the side of the seat lug. Assumes all straight tubes.

The downtube cut length is on the underside, to the outside of the BB shell miter (the most forward part of the hole on the side of the tube). Seat tube cut length is from the top of the BB miter to the top of the seat tube. Top tube length is on the top, miter to miter. Chainstay cut length is from the inside miter on the chainstay.

The jig and angle readouts are for our jigs and our mitering equipment. I couldn't figure out how to take them out in the HTML.

Feel free to ask questions or tell me how dumb I am with HTML or just in general.

OH and if anybody has any jigs they would like me to make forumulas for to set up I am happy to. I've already done it for the bringheli so you can set it up easily and very, I will put that in when I find someone reliable who can convert excel to HTML!

Edit: OH one more thing. If you type in a sloping top tube, the top tube length under "major dimensions" becomes effective. But effective from the TRUE ST/TT intersection, horizontally to the head tube. RATHER than the normal which would be from the IMAGINARY ST/TT intersection. Hope that makes sense.

PS if anybody can clean up the HTML I would really appreciate it, or figure out how to fix those 2 broken cells that would be awesome for the community!

PrairieDog

Very cool. Thanks for sharing. I'm on my first frame, so I'm keeping the dimensions simple, but I suspect that I'm going to have so much fun with this, I will probably try at least another frame.

BTW, I am toying very seriously with the idea of taking one of your workshops...

sannerbikes700

Of course, I'm sure someone will find it useful. Great that you are diving in and building a frame, we would love to have you in the workshop.

PrairieDog

I'm just up the road in Lubbock, so Austin would be relatively easy for me to swing. BTW, do you do custom forks? I don't feel confident enough to try one.