Calling the China Girl crankshaft experts

[Wrench]

I've seen a couple motorized bicycles that had frame failures of the seat post tube. There must be some serious stresses on that tube. Doh, forgot to buy cigarettes on the way home....back on the bike! Thanks All!

@ M/B speeds the rear of the bike will flex in turns
Side rails on my Whizzer cracked but it didn't happen until after 30k miles, So it's a really good frame
I welded the cracks once but it cracked again by the weld

Sometimes reinforcement is needed

 

[Jayraye39]

@ M/B speeds the rear of the bike will flex in turns
Side rails on my Whizzer cracked but it didn't happen until after 30k miles, So it's a really good frame
I welded the cracks once but it cracked again by the weld
View attachment 201394
Sometimes reinforcement is needed
View attachment 201392
View attachment 201393
View attachment 201395

 

[Jayraye39]

that plate will work well for you. Great beads by the way.

 

[Wrench]

that plate will work well for you. Great beads by the way.

Yeah she needed reinforcement in that area, I made that repair about 10k miles ago, everything is holding strong
I still inspect the frame every time I change the oil, which is every 100 miles

 

[Amwicr]

My Huffy frame broke on the seat post tubing, right where the factory drilled holes for the optional water bottle were drilled into the frame.

I'm 99% sure mine didn't have those holes. I got rid of it for nothing

 

[robe]

It would be hilarious if someone made a manual for these and made it to resemble a Chilton manual.

It would have to be written in Chinglish to be of any value at all.

 

[robe]

So, a serious question. I have a standard CG motor and the wrist pin has a ton of end play and general slop. I got a new wrist pin bearing that fits much better but the slide to side play is huge. So would there be any problem with putting a couple of copper washers on either side of the connecting rod to tighten it up a bit? The washers I have are a nice fit over the wrist pin.

 

[GW's Motorized]

So, a serious question. I have a standard CG motor and the wrist pin has a ton of end play and general slop. I got a new wrist pin bearing that fits much better but the slide to side play is huge. So would there be any problem with putting a couple of copper washers on either side of the connecting rod to tighten it up a bit? The washers I have are a nice fit over the wrist pin.

@Jayraye39 did something similar with his engine.

I'm 99% sure mine didn't have those holes. I got rid of it for nothing

Mine did, but I welded them up. I check the frame regularly for cracks.

 

[Jayraye39]

Thread 'FREE needle bearing spacers 4 high RPM' https://motoredbikes.com/threads/free-needle-bearing-spacers-4-high-rpm.62360/

 

[robe]

Thread 'FREE needle bearing spacers 4 high RPM' https://motoredbikes.com/threads/free-needle-bearing-spacers-4-high-rpm.62360/

Thanks for the link. To bad I don't have any old pistons around.