Hi,
Originally Posted by
Sixty Fiver
have not done any scientific testing but...
The same thing happens when you use a standard hub generator on a smaller wheel and why Son makes a hub generator for 20 inch and smaller wheels that does not work properly with larger wheels due to low speed voltage issues.
Please read what we are reading (BassNotBass did a
pretty good job here). For hub generators, you are correct - it is angular speed (rotations per minute) that matter. For bottle generators, it is linear speed. It really is.
If you need to, work out how much the bottle generator wheel moves (assume it has a radius of 1/2 inch) against a 20" wheel that has rolled 5 feet and a 700 c wheel that has rolled 5 feet. You'll see that the bottle generator has turned the same number of times. If both wheels make it turn the same amount in the same distance, than both wheels will make it turn the same rotational speed if they are going the same linear speed.
None of this affects how well a folder works for commuting, so hopefully we can get back to the issue at hand. If you have questions, feel free to PM me.
Cheers,
Charles