my ratfink finked out

[foyeburger]

well im bummed the top tube snapped below the gas tank so i got
one of those pipe clamps and clamped it together then the vibration moved down to the bottom of the seat post and cracked there . so now have to weld it back up talked to buddy of mine and he'll help put it back with some reinforcement ill ride it around awhile after that to see if any more vibration cracks occur then probably sandblast and paint bummer its such a fun bike to ride

well the seatpost you cannot see it but its cracked across the bottom by the weld . but i started my new project the nirve bike its blue spent all day fabrication a front motor mount that i think will work grinded and hacked all day then took it over to my buddys and he welded it up then grinded it down and painted it

so here is the before picture of blue nirve bike i hope this motor mount works im going to try to mount the engine above the chain guard well have a happy new year larry

 

[foyeburger]

 

[Tom]

Damn! i have never heard of the engine cracking the frame. I have never run into that problem myself. Good to see that you are repairing it.

 

[gone_fishin]

that's too bad, foyeburger, you sure it was vibration & not the shocks of high-speed running that did it?

i'm aware of those clamps, never thought they'd be that reliable for frame patching.

that nirve looks kick-butt, dude, can't wait to see what you come up with...are you gonna drill & bolt that mount or clamp it?

 

[foyeburger]

the break were i put that pipe clamp is a clean break almost like a pipe cutter did it n alls i can think it was was the strech frame yes i go fast at high speeds but got me im guessing the vibration found the weak spot ive been riding it for about 3 months . other bikes ive built never happened unless the frame was a lemmon im going to drill into the frame on the nirve bike to mount the motor mount thats the plan anyway always makes me nervous to !! but i dont percive a problem larry ca

 

[Cookie]

Hay guys rember a few month back some one was talking about "drilling a motor mount" for the bike and I had a cow about the vibration and the metal fatigue a lot of these bikes are made out of cheep metal that is not made for the vibration once you put a weak spot in the tube you shorten the life of the bike.......we use those ignition coile brackets from auto zone it takes a little time but they work great.
Also if you can get some rubber matting or some such put a thin layer around the tube where you are going to put the brackets they will absorb a lot of the vibration do the same thing for the gas tank the bolts at the tank will start to leak after a few times tightening them.

Cookie

 

[srdavo]

sorry to hear about your rat fink. the Nirve chopper has been my dream bike for a couple years. can't wait to see one with an engine. keep us posted.

yes Cookie.... I wrap the frame with sections of bike innertube. I have some truck innertube too...really thick. glad you mentioned the gas tank. those little mounting studs are scary. haven't had a leaker...yet, but "rubber mounted" ya don't have to tighten really tight cause the rubber grips the top tube well. I usually double nut everything.

Dave

 

[nogoodnic42]

Hay guys rember a few month back some one was talking about "drilling a motor mount" for the bike and I had a cow about the vibration and the metal fatigue a lot of these bikes are made out of cheep metal that is not made for the vibration once you put a weak spot in the tube you shorten the life of the bike.......we use those ignition coile brackets from auto zone it takes a little time but they work great.
Also if you can get some rubber matting or some such put a thin layer around the tube where you are going to put the brackets they will absorb a lot of the vibration do the same thing for the gas tank the bolts at the tank will start to leak after a few times tightening them.

Cookie

Well said Cookie. There is a reason that this thin tube has no holes in it to begin with. The last thing I want to hear is that someones frame folded under them at 30mph because of a couple of small holes. I personaly use muffler clamps that mount solid with no vibration. With your Nirve or Electra, you could use the correct sized square U bolts like the ones here http://autozone.com/servlet/UiBroke...NE|~NONE|~NONE|~NONE|~6.2|~NONE|~B|~SUP|~true . Heres a pic of my mounting bracket...Kelly

 

[foyeburger]

those look like muffler clamps sweet i already drilled into the nirve bike but will probably use other alternitives to not do that anymore but what gets me is none of the breaks were anywhere near holes that were drilled i guess it messes with the integrity of the thin pipes to begin with larry ca

 

[Cookie]

when I got out of high school (back in the stone ages) my first job was with Douglas aircraft I was a structual mechnic/assembler and you learn a lot about metal and structer doing that kind of work and you never forget it
The bosses iumpress you with the fact that it takes more than one rivet to hold a plane together but it only takes one for it to vibrate apart.

Cookie