Showing posts with label gears. Show all posts
Showing posts with label gears. Show all posts

Monday, July 6, 2009

Rear suspension

Here is a look into the rear suspension. I figured I could either use bushings or bearings for the pivoting point of the suspension. I am not sure what would transfer the least amount of noise to the body of the velomobile. I would think that polyurethane bushings would absorb the impact and disperse any road noise. I am not sure if friction is a critical factor with this part of the suspension. Its not a continuously moving part like the wheel bearings, which require an efficient low friction manner of spinning.

Tuesday, June 16, 2009

Velomobile Gearing

Ok, I am just thinking about how to configure the chain and had a thought about having a gear box of some sort. I was searching the net and found some internal geared hubs for bikes. It looks like one could be modified to have a gear retrofitted where the spokes attached or at the disc brake attachment holes. Looks like several company are producing them, which should allow for a variety to choose from.

The electric hub , that I plan to use as the rear tire, has five sprockets for a derailleur set up. I could use the a single speed sprocket at the pedals and attach to the internal gear hub before the rear wheel. An eight speed internal geared hub would give me a total of forty gear options with a rear derailleur. The best location for the geared hub could be the pivoting point for the rear hub, which would reduce movement of the rear suspension as the chain pulls taught. This would require at least one idle pulley between the pedals sprocket and the hub.

The other option is to bring the hub inside the velomobile and have no pulleys between the pedal sprocket and the hub, but this would still require a pulley at the pivoting point to lessen movement of the suspension as the rear chain pulls taught.

The geared hub would allow for gear changes, while parked at stop signs or lights. This definitely deserves more attention.