Performance calculator excel file

Foilsim - Basic Aerodnamics software - freeware

This program plots a drawing of a mitered angle on tubing.

Another tube mitering program by Giles Puckett produced Dec 1998. And the text file to accompany it. (Probably the same as the one above)

Ackermann steering design
Spreadsheet program for trikes by Peter Eland

The Paterek 2.0 Framebuilders' Design and Plotter Software

Java programs to make frame design of standard bikes quick and easy. bikeCAD, tandemCAD, fullSuspensionCAD wheelCAD

- Excellent Drive train calculator, which calculates gear inches and actual speed.Incl Schlumpf mountain Drive and intermediate drives.
- Gear calculator for Windows (software by Rod Heilfron)
- Gear calculator for Amiga, IBM (software by Wayne Clement)
- Gear inches calculator, in MS Windows executable format (software by Sean Slattery)
- Bike gear program (software by Rod Heilfron)
- Bike Gear Ratio Calculator for Win 95 (software by Pewter Sobey)
- Gear Ratio Program
by Lindsay Steele

- Date: Fri,
14 Jul 2000

From: alex wetmore

Subject: RE: [hpv] Online calculators?

List-Id: Human Powered Vehicles Mailing List <hpv.ihpva.org>

On Thu, 13 Jul 2000, Shaw, Byers Jr. wrote: I wanted to order it with 11-34 and 62 while he insisted 12-34 and 60 would give me plenty of gear inches. Of course, I had measured the actual diameter of the wheel and tire (Primo Comet 1 3/8) and obtained 18.5 inches. The 60-12 gear combo he claimed yielded 100 inches [ > (60/12)*20 ], while I insisted it gave 92.5", an unacceptably low set up. Your spreadsheet proves my point, viz. that on the road, I was spinning out at about 30-33 mph (your chart shows 120 rpm at 33 mph).

This is a very common mistake, even with larger wheels. A lot of people assume that a 26" mtb wheel with 1" slicks is still 26" (or close enough when doing gear inch calculations) when it is really closer to 24".

I usually use 24.5" as the wheelsize for MTB wheels with slicks, and 18.5" for BMX (406) rims with slicks. The true size varies a little from here, but these are much better estimates than 26" and 20".

One simple formula that gets close is: (rim diameter + (2 * tire diameter)) / 25.4

So (406 + (2 * 37)) / 25.4 = 18.9

(that is for the Primo Comet).

The true measurement is often a little less, but this is close.

- Spoke
Length Calculators

- Free Excel spoke length
calculator

- Seattle University
Cycling Club's spoke length Excel spreadsheet

- Based on Bill Patterson's equations here is a spoke length
calculator

- Date: Fri, 21 Jul 2000

From: Bill Patterson Assoc. Prof. Mechanical Eng. CALPOLY SLO

Here is a spoke program that I wrote many years ago. It seems to give the proper answer. Feel free to use it as you will.

'SPOKE CHART PI = 3.141592654# 'FOR MEASUREMENTS IN INCHES KORR = 25.4 'FOR MEASUREMENTS IN MM 'KORR = 1 'INPUT INSIDE DIAMETER OF THE RIM

INDIA = 23 + 7 / 8

'INPUT NUMBER OF SPOKES

N = 36

'INPUT CROSSES

C = 3

'INPUT OUTSIDE NUT TO NUT LENGTH

ZO = 4 + 3 / 4

'INPUT NUT TO FLANGE LENGTH

Z1 = 1 + 3 / 8

'INPUT FLANGE HEIGHT/RADIUS

RFL = 1.125

THETA = C * 4 * PI / N

R = INDIA / 2 X = R * COS(THETA) - RFL Y = R * SIN(THETA) Z = ZO / 2 - Z1

SP = KORR * SQR(X ^ 2 + Y ^ 2 + Z ^ 2) PRINT SP; X; Y; Z

Thursday, 29 January 2009