Frames - how do you determine the quality of the welding?

Finfan

New Member
Aug 29, 2008
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Tucson, AZ USA
I am hoping to purchase a bicycle this week for my "learner" bike. That is the bike I intend to make all of my mistakes with before I build a "good" rider. Naturally I want to do the first one as cheaply as possible since my funds are rather limited. I assume the inexpensive bikes will be rather iffy on QC so I was wondering how can I judge the quality of the welds on the frame? If anybody has pictures that would be really useful! I read on another thread that the Huffy Cranbrook was to be avoided. Does anybody have anything to add to that? Thanks!
 

Dave31

Active Member
Mar 1, 2008
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Aztlán, Arizona
I do not know anything about the Huffy

A good 4130 chromemoly frame should do you well...as far as the welds a visual inspections is about the best you can do. All the frames that I have seen that have failed have never failed a weld.
 

comfortableshoes

New Member
Jul 22, 2008
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Beverly, MA USA
I'd pic a nicer used bike off of craigslist if that's available to you, you can get a nicer bike, for about the price of a cheap one at wally world. All the cable stretch will be out of the cables etc. It will also be easier to ride. There is nothing quite as nice as a nice well built frame that feels good.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
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up north now
That was me with the Cranbrook weld info....I bought an older Cranbrook and the welds are nice. The new ones's I saw at W mart were terrible squiggly little welds.

Just look and see that they are straight on the unions of the two pipes and not all lumpy and spotty.
 

eDJ

Member
Jul 8, 2008
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Wayne National Forest
I've been around a lot of yard sales and flea markets and have seen plenty of good solid bikes that looked terrible, tires flat and rotting, dust caked on the paint etc. Most were built in the sixties and seventies in the USA and could be had for $5 bucks. The main thing was they were build in a time that they built quality bicycles that could actually be worked on, overhauled, maintained and expected to last a few decads.

If you buy one of these, expect to take a few days to pull it down and clean it to where it looks like new. Check the rims to see if they look true by turning the frame upside down and slowly rotating the rim to see if there are places that seem bent. If they look OK, then just check you spoke tightness (1/8 turn each to start with if they seem loose) You'll likely buy new tires, tubes, and rim bands for your project.

Different bike makers use various construction techniques. I paid $5 bucks for a Ross which has lugged frame tubes. (these are fancy looking fittings the tube is inserted into before the brazing or welding takes place) Some use butt welds, while others make special extrusions for the frame head where the forks mount, the pedal crankcase, etc. These have nipples that the tubing is
inserted over before the welding takes place and afterwise is ground smooth
so it looks seamless. (Schwinn used to do this)

If you go to a public library or the net and look up bike frames in bicycling books there will be chapters which address all this. But for not I'd suggest
that an older bike for cheap that doesn't appear all rusty may be a stable platform. Often boy grow up leaving the bikes behind in the garage, basement, or barn and that's it until mom and dad want to clean the place up.
Many a good bike is had this way for purposes like yours Finfan.

In recent years some cheap crap has been made and sold thru volume discount stores. I've talked to bike mechanics in old time bicycle shops and they have shown me some examples of this. In a book we were assigned to read in Design School, titled "Design for the Real World" by Victor Papanek....the surveys listed various items and their life cycles in the USA compared to other countries. A bike in the USA would last 2 years where in like India it would last 50. (from good care) But I figure places like India wouldn't have the cheap junk sold or purchased there by big discount chains.
So, read up on bike frames and what's "quality" and hit some yard sales. I once purchased a Raleigh made with special Reynolds tubing at a Goodwill thrift store for $15 bucks (that had sold new for over $700) Often yard sale, flea market, or thrift store people haven't a clue what the stuff is worth.
 

lennyharp

New Member
Jul 19, 2008
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Mesa Arizona
Here is an article that goes into some detail about this type of fabrication per the Schwinn high end bikes.

Fillet-Brazed Schwinn Bicycles 1938-1978

I personally build this way as I do custom angles and such but for traditional the luged build is good. mostly for the motored bike we need the tubing not to be too thin. The top end bikes usually use tubing that is very thin to save weight. You can get away with this when you have a weak motor like a human being. An engine has at lest 3 times the power and many times the vibration of a person. This translates to a falling apart bike if it is not made stronger than a light weight racer or a department store junko bike. To be safe a 1960 to 1990 vintage touring or mountain bike will usually have strong enough tubing especially if it is Chromium Molybdenum, or cro moly steel tubing Aluminum and carbon fiber fatigue and break easily compared to cro moly steel which is a spring steel. Now if you have some bucks get a titanium fabricator to make a titanium frame to motorized bike standards and you will maybe have the most indestructible frame going.
 

Blakenstein

Member
Sep 15, 2009
561
2
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Alta. Canada.
There will be a sign on the weld saying weather or not it is good. If it is a bad weld, then the sign will be on the bottom on the left hand side of the weld-the sign will say"gabbatoo" If it is as good weld then the sign will be on the top right hand side of the weld and the sign will say "BillyBush" :):):):)
 

spit_fire

New Member
Aug 28, 2009
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Brampton
I started my first project bike with a NEXT bike from wallmart it was the cheapest brand new bike available, by the time i got the bike to not fall aprart it was great but i replaced alot of parts but the frame was always good i find its everything else that goes such as cheap wheels and forks always seem to go i gues from harder impacts at higher speeds and poor quality forks, ill tell u id rather go with a decent used bike than a brand new cheappie from walymart
 

a_dam

New Member
Feb 21, 2009
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Momence, IL
Very constructive addition to this two-month-old post, Blakenstein. You deserve a -10 on your post count for that, and I deserve a -10 for responding to it and acting like a mod.

Topicwise, though, I love the cheap 1970's steel Schwinn frames (varsities, continentals, etc...) that people used to throw away all the time. Almost indestructible. Now that "fixies" are popular, I guess those old bikes are worth something and are harder to find on the curbside. Those 10-speeds are not the cruiser-style MBers prefer. Handlebars can get you more upright, but the narrow frame might not be good for the standard left-side sprocket/chain setup.
 
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Blakenstein

Member
Sep 15, 2009
561
2
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Alta. Canada.
Okay Now....first of all, there is no such thing as " a bad weld" on any store bought bike, cheap or not!! Q. C. highly inspects those welds before those bikes leave. Secondly, the welds are very professionally made by professionals. Thirdly YOU CANNOT TELL IF A WELD IS GOOD JUST BY LOOKING AT IT!!!!!! you can have a weld that looks perfect,nice uniform bead,no spatter or undercut,not too cold or too hot,and great fusion,HOWEVER; INSIDE the bead there can be and in many cases there has been something called POROSITY that will cause the weld to FAIL under applied loads. The only way to detect this is with very expensive X-RAY equipment.
There,now he knows . Can I have my 10 points back??? common please gimme gimme gimme gimme gimme gimme please.:):):):)
 

Blakenstein

Member
Sep 15, 2009
561
2
16
Alta. Canada.
Now that was very informative! I would give you +20 for that! But now you've got me worried about MY welds.
Thanks for the 20 A-Dam, I would not worry too much if I were you, unless you're doing those multi pass pressure type welds, the ones that have root passes,then filler passes and wash passes.:):)
 

bandito

New Member
May 22, 2009
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colorado
Personally I like the geometry and the handle bars on a mountain bike not bmx, I think if you go 1 step above the 70/80/90$ bicycles you can get a quality bike with few problemos. Just today I saw walmart had a brand new mountain type bike for $49 and Im sure the components are terrible. With these kits its enough work getting the right bolts and tweaking it to your taste. Heck with having to worry about the bike too....... mountain bikes respond on a dime and are nimble......anyways Im just ranting bout nuttin.
 

Dan

Staff
May 25, 2008
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Moosylvania
Great info on the welds. Thanks Blacken. My favorite MB (wally world Point Beach) Has crazy lookin' welds that I always liked but worried about.

Most of my builds have been on cheap wally world bikes. All have worked fine and no complaints. But take a steel framed MTB, put cruiser handle bars on it and man! Just rides so much better. Love the looks of the swarly, cantilever frames but especially with a 2 stroke engine, it just mounts better and keeps the vibes down. GoodWill just had a MTB for 8 bucks! Steel, awesome brakes and missing a peddle. Was to tall for me but man.
 

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Blakenstein

Member
Sep 15, 2009
561
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Alta. Canada.
I believe steel frames to be the best- they are the strongest .My summer bike is aluminum but my winter bike is cro/mo. I feel allot safer on my winter bike.
You have nice pictures of a nice bike!! What type motor you got there??-looks like it really hauls.:):):):)
 

Dan

Staff
May 25, 2008
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Moosylvania
Steel really does have a much better feel. Was wondering if it was just in my head. TY. Pic 1 and 3 are a Honda. (I Love it!!! Well worth the $). Pic 2 is either a BGF or Dax 2 smoke. That bike has had at least 3 engines on her and with amazingly lil maint., been a champ. The bent seat post was hand made by 2Door (Tom) completely made it a good ride. The only thing I need to add is springer forks. She is a bit ruff on bumps.

With the Honda/Grubee GB, a lil over 35 MPH. Love the Honda for that. Cruises at 30/34 After that, still vibes less then a china girl and makes a much better sound.

No one get upset! I love my China girls, just sayin'!
 

Dan

Staff
May 25, 2008
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Moosylvania
LOLOLOL, oh yea Tom. Makes her shake her head but ayup

(me got lucky. hot and loving great chick)

My girl of 21 yrs, rocks big time! I'd marry her in a NY min, but she is way to smart for my proposals! (gonna have to get her liquored up)
 
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