Motorized Bicycle Engine Kit Forum  

Sponsors



Go Back   Motorized Bicycle Engine Kit Forum > Bicycle Motor > DIY Home Built Motorized Bicycle (non kit)

DIY Home Built Motorized Bicycle (non kit) Post all about your home built rides here. Weedwacker motors, lawn mower engines ect. This area is for non kit builds

Reply
 
Thread Tools Display Modes
  #11  
Old 02-16-2017, 06:20 PM
cannonball2's Avatar
cannonball2 cannonball2 is offline
Motorized Bicycle Elite Member
 
Join Date: Oct 2010
Location: Colonial Coast USA.
Posts: 3,450
Default Re: Minimalist FD

Thanks Yall!

Well its up and running, just not as I expected. The Briggs was apparently in a bowling tournament somewhere along the way in shipping. The damage was enough for me to refuse it. Sad thing is I negotiated a really good price as it was the last one the seller had. The available replacements cost much more. Will have to look around.

So being all dressed up and no place to go so to speak. I got the old Echo power head from the donor trimmer. Hadn't been run in years but was put up properly. Cranked in a few pulls and settled down to running good as always. Some how I thought it was a 24cc. Nope its the little 21cc. Didn't expect much. Was quite surprised how well it pulled. You have to pedal it to 5+mph then add throttle and its off and running. I'm guessing 12-15mph. That's pulling the throttle cable end by the right hand and steering with the left, not an ideal test!

It really is pretty cool. Not nearly as ungainly/unbalanced as it looks. Once riding you really notice nothing unusual in handling. Its with in the confines of the handle bars so if they fit the engine will too. The little 21cc was always noted for being silky smooth. its a very pleasant little engine. The Lawnboy roller is perfect in design and the size(7/8) works well with the little engine. These rollers drove the mowers in damp/wet conditions, maybe it will work as well with the Hookworms.

So living in the flats this thing is going to work great. Doubt it will climb much of a hill, but bet the Briggs might.

Have to keep looking for another Briggsey, in the mean time I high rollin on 21ccs! Too funny!!
Attached Images
File Type: jpg DSCF2055.JPG (379.4 KB, 28 views)
File Type: jpg DSCF2057.JPG (448.4 KB, 22 views)

Last edited by cannonball2; 02-16-2017 at 06:22 PM.
Reply With Quote
  #12  
Old 02-16-2017, 10:36 PM
curtisfox curtisfox is offline
Motorized Bicycle Elite Member
 
Join Date: Dec 2008
Location: minesota
Posts: 3,688
Default Re: Minimalist FD

Makes for a sad moment when that happens, think the rest of use feel the same. Looks good though, the Briggsey would have more pulling power.............Curt
Reply With Quote
  #13  
Old 02-17-2017, 06:48 AM
Ludwig II's Avatar
Ludwig II Ludwig II is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2012
Location: UK
Posts: 4,485
Default Re: Minimalist FD

Whilst accepting this was made to be ultra simple, I wonder if your belt experience will eventually result in a similar motor with a large diameter roller underneath it and reduction drive set, similar to te old French bima a galet system.
Reply With Quote
  #14  
Old 02-17-2017, 08:55 AM
cannonball2's Avatar
cannonball2 cannonball2 is offline
Motorized Bicycle Elite Member
 
Join Date: Oct 2010
Location: Colonial Coast USA.
Posts: 3,450
Default Re: Minimalist FD

Strangely LII

I have a 49cc HS engine with a 3:1 reduction that I almost inframed driving a big roller probably jackshafted behind the seat post in some manner. This build was more about having a good hybrid(pedal/power) bike.

Its still very light. More bicycle than MB. Got the throttle cable made and hooked up. Will ride a bit today to see how it all works out. Cool thing is almost any of the consumer trimmer motors should hitch right up. Saw a stack of 26cc trimmers in the Depot yesterday for $79. In theory I should be able to take any small trimmer out of the box, remove it from the shaft, mount it on the bike, hook up its throttle cable and go. This build is well under $100(save for the new tires). If one can use a lower power motorized bicycle this is pretty easy to do.
Reply With Quote
  #15  
Old 02-17-2017, 09:49 AM
Ludwig II's Avatar
Ludwig II Ludwig II is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2012
Location: UK
Posts: 4,485
Default Re: Minimalist FD

Is there something compact that turns the drive through 90 degrees? I'm thinking of something like the connection between the motor and the disc on an angle grinder.

On sale in Australia:

Reply With Quote
  #16  
Old 02-17-2017, 10:19 AM
mat_man mat_man is offline
Motorized Bicycle Elite Member
 
Join Date: Jan 2011
Location: athens ga
Posts: 222
Default Re: Minimalist FD

The RYOBI 30cc 4 CYCLE has an external belt/pulleys for the OHC.
If the friction roller could be mounted on the pulley, it could be 4 times larger.

Many Walmart 20" trick bikes have 2.3" wide street tires
that would give a lot of contact area for small rollers.

The last one I bought at Goodwill was $5, painted in girl colors.
Attached Images
File Type: jpg s-l300.jpg (11.9 KB, 19 views)
Reply With Quote
  #17  
Old 02-17-2017, 12:09 PM
cannonball2's Avatar
cannonball2 cannonball2 is offline
Motorized Bicycle Elite Member
 
Join Date: Oct 2010
Location: Colonial Coast USA.
Posts: 3,450
Default Re: Minimalist FD

Wow those are really interesting motors, Particularly the Ryobi. Last one I had was OHV. This one must be the current MTD 4stroke? Cant believe they would go to that trouble. Must be having to compete with Honda.

Went on a 8mi test ride. Pedaled out 4, powered back. Worked very well with no issues. Hardly noticed it was there pedaling. The little Echo is surprisingly powerful for its size(relatively speaking). I'm betting its easily making close to 20mph. The smaller roller suits its power band very well and lets it rev out completely. A BMX peg would kill an engine this size.

20mph may not sound impressive, but you can actually get somewhere if you aren't in a rush. Heck when I was in Germany as a student in the late 60s people were riding Velosolexes all over the country at 20mph, pretty loaded down too. Its engine was rated at .8hp.
This little engine is the last of the Japanese Kioritz engines, they were extremely high quality. Don't know who makes Echo now. The color changed to orange(which it was long years back) with the new ownership.

With the many newer designed engines out there a trimmer powered FD might be worth a second look. Heck if you were trying to stay legal with the 49cc law you could run two of these engines with 7ccs to spare!

Last edited by cannonball2; 02-17-2017 at 12:18 PM.
Reply With Quote
  #18  
Old 02-17-2017, 04:21 PM
cannonball2's Avatar
cannonball2 cannonball2 is offline
Motorized Bicycle Elite Member
 
Join Date: Oct 2010
Location: Colonial Coast USA.
Posts: 3,450
Default Re: Minimalist FD

So after putting a good many miles on the bike the little Echo began 4stroking. Cleaned the air filter, checked the exhaust screen. All was well. Finally figured when under load it ran fine. As soon a the engine unloads it four strokes. You can actually eliminate the 4stroking by riding the brakes. I'm guessing the carb was a bit restricted in the main jet from sitting and cleaned out richening up the mixture.

So this means its more of a load trimming grass with a string head than moving a 170lb person down the road on a bike. It never four stroked as a trimmer.

This means also that the roller is TOO small. I remembered Lawnboy had a high speed commercial version, the difference in the drive is the rollers size. After researching I found one its 1 1/8 and on the way! Imagine the 21cc had too much power. I bet this will straighten it out.

Incidentally the Lawnboy style roller woks the best of any steel roller I have tried, which were the knurled style. You cant break it loose even when super loaded. At least with this engine. A Cag would be another story probably.

All this fine tuning will perfect the system for a Briggs when I can find one.

Last edited by cannonball2; 02-17-2017 at 04:25 PM.
Reply With Quote
  #19  
Old 02-17-2017, 05:32 PM
Ludwig II's Avatar
Ludwig II Ludwig II is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2012
Location: UK
Posts: 4,485
Default Re: Minimalist FD

Taking drive from the half time camshaft is not an unknown idea.

http://www.moto-collection.org/moto-...p?idfiche=6804
Reply With Quote
  #20  
Old 02-17-2017, 06:20 PM
mat_man mat_man is offline
Motorized Bicycle Elite Member
 
Join Date: Jan 2011
Location: athens ga
Posts: 222
Default Re: Minimalist FD

Tom Bartlett produced Zipcycle from 1993-2003.
Using a belt reduction Friction drive powered by a Homelite 25cc String Trimmer.

"Most bikes would run from 23-25 mph. We experimented with different gearing and found that although we could run a higher gear and obtain slightly higher speeds, the bike had no reserve and the speed fell quickly on hills. So we compromised for a slightly slower speed and moderate hill climbing ability. Basically, the bike was rev-limited at the top end."

Factory Rev-limited by too small of a carburetor to protect the motor is my speculation.

"We used polyurethane rollers that were just slightly harder than the tire compound (this was so that the majority of wear would be on the tire). The result was a roller that gave an excellent grip, but was long wearing. We found we could ride in the rain or morning dew without slipping.
The driver roller was suspended at both ends by sealed ball bearings."
Attached Images
File Type: jpg 658.jpg (48.2 KB, 20 views)
File Type: jpg 458.jpg (28.4 KB, 18 views)
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 07:50 PM.


Sponsors

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
MotorBicycling.com