How do you extend a bike frame?

GoldenMotor.com

Kristof

New Member
Jan 21, 2011
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Aliso Viejo, CA
Hi,

As some of you know, I have built this bike and the rear wheel bearings have seized. My bike has also been tempered with, causing the engine mounting frame to shift, so its not in line with the bike. That is why I am trying to find a bike to mount my engine on. Buying a new wheel is not worth it, its like $40-50.



For those of you who don't know that is a 100cc 4-stroke engine and its pretty bulky.

Here is the bike that i was thinking to extending the frame on.

I have questions:

Why do some people braze instead of weld bike frames?

Where do i get the tubing/metal to extend the frame? Could Home Depot or Lowe's help with materials?

Where could i have some pipe bent? if I need to.
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
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living the dream in southern california
that frame looks like it has an oval (or close to it) downtube. that wouldn't be easy to find. probably have to find a specialty metal supply place and order it. which wouldn't be cheap.

pretty much all bikes were brazed in the olden days (pre 40's) and the practice just carried on with some bikes. it's plenty strong, cheap, and makes those cool looking yellow/gold welds...
 

Kristof

New Member
Jan 21, 2011
232
0
0
Aliso Viejo, CA
This is how I extended mine http://motorbicycling.com/f36/finishing-greyhound-build-12738.html you can get mild steel tubing at the local steel suppliers and 4130 tubing from Aircraft Spruce or Alexander Aircraft.
That's the design I was thinking about. Nice build, I was also thinking to make a trailer.

So, I will have to special order materials?
Where could I get someone to bend pipe for me?
Did you braze or weld?
What if you put the engine in front of you, instead of behind?