## Bicycle Gear Inch Chart

Have fewer cogs or chainrings? Just set the no-applicable values to zero.

## Trail Calculator (Bicycle Geometry)

Here lies a Tableau viz to calculate trail (both geometric and mechanical) and wheel flop. Pneumatic trail is calculated using the classic formula:

([Wheel Radius] * COS([HTA] – [Rake]) / SIN([HTA])

## The State of 650B Rim Brake Compatible Rims

What are the rim brake compatible (non-disc) 650B rims these days? Below is a table of options. Most are made by Velocity (including the below offerings from Pacenti and Soma). I hope this is useful for all of the dozens (literally dozens) of readers!

Measurements above are given in millimeters and grams. Pricing may vary, prices given above are base prices from the Interwebs. Some of the polished Velocity rims are \$30 more. Specs subject to change. I try to get this right, but am held harmless in the event of error. Should an error occur, please notify me.

If I’ve missed anything or if you can fill in the gaps above, please leave a comment and I’ll incorporate it into the table.

## 650B Conversion Tire Clearance Repository

What bike(s) have you converted to 650B? What tires fit?

Have you converted a bike? Comment below with the following and I will update the table:

1. Make
2. Model
3. Year (or era)/serial number/distinguishing feature(s)/color
4. Frame size
5. Largest 650B tire that fit
6. Any 650B tire(s) that you tried that didn’t fit
7. Brakes used in conversion

## Tire Size and Air Volume

Air volume was calculated in MS Excel with the following formula (this example is for 650B/584ISO with 38mm tires):

2*PI()^2*(584/2+38)*38^2

This will give results in cubic millimeters. Volumes above have been convert to liters (dividing by 1 million), rounded to the nearest tenth.

Some variances may be introduced from rounding, unit conversions, and other factors.

This is all white coat, clean room, armchair nerdery stuff only. Real life measurements of tires can vary based on many factors including miles, rims, tubes, production batch, etc.

Tire weights are manufacturer published weights, except for Schwalbe which were 100% fabricated for my own amusement.

Sources:

https://en.wikipedia.org/wiki/Torus

http://www.metric-conversions.org/volume/cubic-millimeters-to-liters.htm