Still want to argue about rubber mounting?

GoldenMotor.com

abracadabra

New Member
Sep 18, 2014
7
1
0
oklahoma city
The whole reason i chose to include rubber in my mounting was because i had broken every motor mount bolt on the engine at least once. I finally replaced with larger bolts but i couldnt help but think that was gona resolve it. . I figured that vibration was behind the problem so i tried a couple different matterials and locations as where to use it before i got it where i can trust it to get to and from work everyday. These bikes are alot of fun when they work.
 

Technocyclist

Motorized Bicycle Senior Technologist
Jul 7, 2008
462
0
0
Asia
The material i use on my mount is a rigid flexible material, that's oil, fuel, and heat resistant, and can be easily found for free. Guess what it is? it's an old and used timing belt. I find the wide ones to be more effective, the ones used on V6 and V8 engines. You can get these used timing belts in any auto repair shop for free. However, you will need a very sharp cutter to cut this into size, because it's Kevlar reinforced. Never had any problems with this setup.
 

Tyler6357

Well-Known Member
Mar 15, 2012
1,293
294
83
Santa Barbara, CA
When I first built mine I put rubber on thinking it would help protect the frame but after I joined this website I removed it after been told it's not a good idea. I figured, these guys know and there is no sense trying to re-invent the wheel.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
http://motorbicycling.com/album.php?albumid=1702 upoaded a pic of a application that works.
The difference between your concept and the one used by most is that the rubber is not between the engine and the frame. Your mount more closely duplicates the resilient mounts used in automotive and motorcycle applications whereby the mount fasteners are not directly subjected to the vibrations. Not perfect but better than sticking rubber between the engine and the frame. Glad it is working for you.

Tom
 

abracadabra

New Member
Sep 18, 2014
7
1
0
oklahoma city
I think we can all agree that there is no "perfect" solution to the real problem of vibration. I just thought id share what i
thought was a reasonable argument to an ongoing thread.
Lol Still wanna argue about it? jk
In all fairness i wish i had found this forum along time ago.it has been very useful . My first bike was a gift from a neighbor who used a paint roller as a spacer on the clamps under the gastank. .......so i started with a seriously rigged bike. There wasnt a single piece that didnt break,come loose or leave me stck on the side of the road. I bought a whole new kit and built it the way it should have been done the first time. If it were not for the useful info herei it would have been another learning process.nt it?
 

bowljoman

New Member
Aug 7, 2010
370
1
0
Wa
The best solution to stop your ride from vibrating, is to sit on a 9 inch scooter tube with enough air in it to lift your ass up. Trust me, you'll never ride the same again!

Seems to me , rubber or not, is the choice of the builder, where as the design of the bike frame itself was never meant to have any kind of muffler clamp tight enough to hold a running engine. It also appears to me that those clamps are not really the main factor in having a lasting frame application. Seems to me its being tucked into the bottom bracket with proper angle in the engine side of the clamps. Ive only used the 49CC weed wacker motors with motor mount plates. The mounting plates flex enough!

Im totally against rubber mounting because when you either pull start or bumpstart, the engine looks like its going to be ripped off the frame.
 

Chainreaction

New Member
Dec 14, 2014
159
0
0
Tulsa OK
Long ago I was a mechanic. As I recall in most situations there was a steel bracket bolted to the engine, a steel bracket bolted to the frame. The motor mount was in between these two brackets, commonly made of rubber and steel. Motor mounts would go bad and need to be replaced, but it was rare to see damage to the brackets.
 

TheSignGuy

Member
Nov 24, 2014
459
9
18
seattle, wa

Look carefully.
See the white pad between the mount plate and frame under the Ubolt?
Notice the flattened frame tube? Caused by overtightening to try and stop inevitable engine movement caused by rubber.
Notice the visible distortion and damage on the chunk of downtube still visible?
Also notice the damaged area (paint worn off where engine rubbed) clearly visible on the broken section of seatpost tube from VIBRATION causing ENGINE MOVEMENT.


DON'T USE RUBBER OR ANY TYPE OF COMPRESSIBLE MATERIAL IN YOUR MOTOR MOUNTS.
*Wipes spittle off monitor screen*

How did you get the photos to go up, all my photos are online incompatiable as I have a HTC one m8. Super nd photos and standard.

High quality .
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
How did you get the photos to go up, all my photos are online incompatiable as I have a HTC one m8. Super nd photos and standard.

High quality .
I upload my pics to photobucket (free but annoying sometimes) and link to the forum thread by copying and pasting the "IMG" link. Then the pic shows instead of a link to the pic.
"" Plus some removed characters(removed to show link instead of pic)
Without the two ## will show in thread as a picture.
[URL=http://s875.photobucket.com/user/maniac573/media/kohler_zps5301ded9.jpg.html]




Well. It showed the pic even with some parts of link removed, but you get the idea hopefully.
Just use "IMG" link copy and paste.
 

Chainreaction

New Member
Dec 14, 2014
159
0
0
Tulsa OK
Rubber only works correctly in a motor mount if it is a sandwich design, two plates with rubber glued in the middle, no clamping action. Obviously you would need more than two of those type of mounts for a motorized bicycle.
 
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maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
It's off the net. And it's a 16hp iron block with a roller bearing crank. NOT a 4hp. Lol!
I wish I still had one of these. Flat. Out. Indestructible.
I have some real good memories of the engine that made me look this pic up for another thread. Check out "Gearhead Memories" In tavern