View Single Post
Old 09-19-2010, 11:31 AM
msrfan msrfan is offline
Motorized Bicycle Elite Member
Join Date: Sep 2010
Location: Southern California
Posts: 1,484
Default Re: Plagued by vibrations

Thanks Kip. Good idea. I've gasket matched before with good results. I have the dremels and a large die grinders and a good assortment of burrs and bits. I think I'll get the main vibrations squared away first. I'm really leening toward the frame as the problem because the engine area is quite large with 1 1/8" tubing. All the other frames I've used were fat tube with small engine areas. I'm thinking my frame is rattling too much. I'm almost ready to try the motor in my Panama Jack. I'll post the results. When I get ready to do some porting, I may need your help.
Hi Bairdco. The things that are loose are from the vibration. Actually I like your suggestion of clamping the exhaust. Seems to be a lot of weight hanging way out. I've really built seven, (I lost count), other bikes all using BGF motors with no extra bracing and had no problem. They all ran fairly smooth. I don't have any long range reports because some were sold to strangers that saw me riding them and offered me a good price. The others went to friends, (no profit there), and they don't ride them much. Then I bought three more from BGF and the first one vibrated a lot, so I put the second one in the same bike with the same results. That's when I made a head stay to triangulate the mounting. It was better but not good enough. So, I paid a premium for a Grubee starfire and installed it without the head brace and it was better but still not good enough. I didn't use the brace because the Grubee has 6mm head studs and the BGF's are 8mm. I plan to make a head stay for the Grubee and try it out next weekend. Also I will make a clamp for the exhaust and maybe weld in a gusset under the motor to stiffen up the enging mount area. I will tighten everything that's loose before I continue. This bike is an older cruiser, maybe a Huffy or Murray. I'm determined to use this frame.
Another thing that has intrigued me is balancing the crank assembly. After studdying all the info and visiting my buddy at an automotive maching shop, I 've come up with a formula for balancing without disassembling the crank. Totally untested but the calculations work.
Thanks again for the help.

Last edited by msrfan; 09-19-2010 at 11:34 AM.
Reply With Quote