- Mar 14, 2011
Does your crank spin while under engine power?Well, this my second bike using the inexpensive, light weight 5:1 scooter gearbox
and a double right-sided drive. This gearbox has a flat front face on the drive side
which allows attachment of ordinary hardware store "L. s," then the motor/gearbox
can be bolted to a motor mount which attaches to the bicycle frame.
Here's the gearbox: https://www.monsterscooterparts.com/trfor3336434.html
The concept allows conversion of engines that do not have fastening points at their base
to chain drive. Any motor 2 or 4 stroke that fits the gearbox can be converted
to chain drive. Here's a link to the first bike I did using steel staton supports for
the rear of the bicycle motor mount:
This is my new build, finished which I consider an advancement of the art of motorized bicycles because it has so many benefits over current designs, like the Dax chain drive and the GEBE belted drive. Here's some pics: Here are the benefits: 1. Low cost gearbox 2. Motor close to tire for...motoredbikes.com
Here's the advantages of the concept:
1. All weather chain drive.
2. Motor is positioned closer over the wheel than friction drive.
3. Since there are two independent free wheels, with the motor off
it rides freely like a bicycle - no clutch drag.
4. Wide selection of gear ratios; drive sprockets, 8mm, come in
10,11, 12,14,17, and 25 teeth, and the 8mm wheel sprocket is available
in 44,54,63, and 72 teeth. I have used a 11t drive, and 44T wheel sprocket
for an estimate top speed of 24 mph, but far higher top speeds are
possible with different combinations, like 40-50mph.View attachment 173075View attachment 173076View attachment 173077View attachment 173079View attachment 173080View attachment 173081
5. Accepts a wide variety of motors, like Honda GX50, GX35, Subaru EHO 35,
Tanaka PF-4000, and 3000, and Zenoah G43L.
6. No chain tensioner is required.
The drive is built by:
1. Removing the multi-speed cassette.
2. Screwing on a freewheel with the rear 8mm sprocket bolted to it.
3. Inserting a 1/8 inch spacer washer over the first freewheel (from McMaster-Carr).
4. Screwing a single sprocket bicycle freewheel.
5. Using an 8mm chain.
NOTE: The basic frame mount has to be made of aluminum back with steel angle iron or just
use steel angle iron. The mount here is back with angle iron.
Here's some pics: