Showing posts with label internal geared hub. Show all posts
Showing posts with label internal geared hub. Show all posts

Thursday, June 18, 2009

Chain Routing


Attached is an option to route the chain. I want to have a geared hub in the middle to use as a transmission. This will allow for several gear ratios and help keep things simpler around the pedal sprocket. The pedal chain, left chain, would change levels with a idle sprocket, then run to the the geared hub, call it a mid drive, to the point where the rear suspension pivots. This should keep the rear suspension from tightening at pedal start up before any forward movement takes place, at least lesson the movement. A final chain will complete the power transfer to the rear tire sprocket. This is not drawn to scale and is just representative of the idea.

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.