E-Bike Blog 3

Research Stage 3, 3/12/18 - 10/12/18:

To move from the desk test setup to the first ridable prototype, P1. I will need to buy a clamp for mounting to the seatpost or the bikes frame (these seem to be the most straightforward mounting locations so I will focus on them for the first mock-up). I think it makes sense to buy a commercial seat clamp (known as an “O-clamp” or an “axle clamp”) as they are readily available and made to fit the range of tube sizes.

Common min and max diameters for bike seatposts: 21.15 - 34.9mm

Common clamp sizes: 28.6mm, 31.8mm

Source

Seat Tube Sizes:

“If you know the size of your seatpost, it’s straightforward as there are only 3 clamp sizes:

28.6 if you’ve got a steel frame with a 27.2 or smaller seatpost

31.8 for alloy or titanium frames with a 27.2 or smaller seapost

34.9 for virtually everything else i.e. most frames that take a 31.6mm post.”

Source