PDA

View Full Version : My E-cumbent project


recumpence
06-15-08, 11:18 AM
I am new to this forum. I posted this in the electric bike section, not realizing there was a recumbent sub group.

http://www.bikeforums.net/showthread.php?t=429999

Enjoy!

Matt

Floyd
06-15-08, 03:31 PM
Looks good at quick glance, I need to come back later and look some more.

JanMM
06-15-08, 08:33 PM
Probably less interest in powered bikes here than in the electric forum.

ejserv
06-15-08, 09:35 PM
Thanks Matt! Very impressive! Do you know if a rc esc can be used to drive a car alternator as a motor?
Ed Service

recumpence
06-16-08, 06:45 AM
I do not think so. This subject was convered in another forum I read a while back.

Matt

Doug5150
06-16-08, 11:45 AM
I am new to this forum. I posted this in the electric bike section, not realizing there was a recumbent sub group.

http://www.bikeforums.net/showthread.php?t=429999

Enjoy!

Matt
The motor work is great, but your 24-spoke back wheel is much too flimsy for motorization, IMO.

A lot of people have already found out that even using 32-spoke wheels, 16-gauge spokes are not strong enough, and many times 14-gauge spokes may not be either. People on motoredbikes.com tend to use 12-gauge x 36 spokes, or 11-gauge if they can get them.

And I would change the front wheel to a 32- or 36-spoke as well. To an extent this depends on how you ride, but a lot of high-end bike parts that work just fine at 15-20 MPH will not last long at 30+ mph, and the spokes are often the weakest link.
~

recumpence
06-16-08, 05:23 PM
The spokes only break from the weight of heavy hub motors jarring the spokes over bumps, not horsepower. Look at it this way, most mountain bikes have 24 spoke wheels. I have one myself with 24 spoke wheels. If you have disc brakes on those wheels, the stopping power is handled by the spokes. However, have you ever heard of anyone breaking spokes from hard braking? Neither have I.

I even bought a 36 spoke, large hub flanged rear wheel for this project, fully expecting the rear spokes to object. However, I have 100 miles on it so far without any problems, and trust me, I have been riding it hard.

Also, the front wheel is not a problem. The brake was, though. I went to a larger disc for better braking.

I understand your concerns, but, as I mentioned earlier, the issue with broken spokes on e-bikes is the heavy hub motor puting huge tugging stress on the spokes from hitting bumps, not from rotational power applied to them.

I spent ALOT of time looking into this (after all, it is my bacon on the line if something breaks at 35 mph).

Its all good. 100 miles and going strong!

Matt

recumpence
06-16-08, 05:24 PM
Doug, where are you at? I live in Mc Henry county Illinois. If you are close, you can come by and check it out!

Matt