Info on building Chopper style bike

[Richard]

Hello,

I'm wondering if anyone can direct me on finding information on building a
Chopper Style Bicycle?

I just spent about 4 hours searching on the Net and found lots of places for
parts, and one pictoral view of a Regular bike turned into a Chopper Style
bike. But did not find anything more detailed.

Can anyone direct me to an Online place with specs on Converting a Regular
bike into a Chopper Style bike , (long front forks, long handle bars).

Thanks in advance,
Rich

 

[Werehatrack]

On Tue, 31 Aug 2004 22:21:01 -0500, "Richard" <[email protected]>
wrote:

>Hello,
>
>I'm wondering if anyone can direct me on finding information on building a
>Chopper Style Bicycle?
>
>I just spent about 4 hours searching on the Net and found lots of places for
>parts, and one pictoral view of a Regular bike turned into a Chopper Style
>bike. But did not find anything more detailed.
>
>Can anyone direct me to an Online place with specs on Converting a Regular
>bike into a Chopper Style bike , (long front forks, long handle bars).

Just lengthening the forks and bars won't do the job properly. The
lengths and angles of the top and down tubes will still be wrong, the
seat tube angle and/or length will be wrong, and the angle of the head
tube will be wrong. If you merely put an extended fork on a
conventional frame, it must either lift the bottom bracket and rotate
the seat position over the rear wheel to a level that's going to make
the bike uncomfortable (and possibly unsafe) to ride, or it will
extend the front wheel's position to a point well forward of the
steering axis, producing an inadvisable fork geometry. To build a
chopper-style bike successfully, you really need a frame that's
specifically designed to accomodate the complementary fork. Modifying
an existing frame is possible for certain frame types, but it would
most likely be far cheaper to just buy a bike that's built in that
style to begin with unless you have the requisite metalworking
equipment and skills to bring to the project. (And if you have those
skills and equipment, the task needs little explanation.)


--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Dave Wilson]

Werehatrack <[email protected]> wrote in message news:<[email protected]>...
[...]
> steering axis, producing an inadvisable fork geometry. To build a
> chopper-style bike successfully, you really need a frame that's
> specifically designed to accomodate the complementary fork. Modifying
> an existing frame is possible for certain frame types, but it would
> most likely be far cheaper to just buy a bike that's built in that
> style to begin with unless you have the requisite metalworking
> equipment and skills to bring to the project. (And if you have those
> skills and equipment, the task needs little explanation.)

I have mig, tig and gas welders, as well as a tubing notcher, chop saw
and grinders. Plus I have access to a lathe and milling machine. And
I know how to use them. But I have no idea how to lay out the
geometry of a bike frame.

I have thought about building a chopper to bring to the local chopper
rally.
http://www.floridacycling.com/Gallery Pages/Chopper041404/Chopper041404.htm

Where could I find out more about designing a chopper-style bike?

thanks,
Dave
www.davewilson.cc

 

[J. Garland]

> I'm wondering if anyone can direct me on finding information on building a
> Chopper Style Bicycle?
>
> Can anyone direct me to an Online place with specs on Converting a Regular
> bike into a Chopper Style bike , (long front forks, long handle bars).
>
> Thanks in advance,
> Rich

Try these guys: CHUNK 666
http://www.dclxvi.org/chunk/index.html


They actually have a Chopper workshop if you are in the Portland, OR area:
http://www.dclxvi.org/chunk/operations/workshop/index.html

Good luck!!!

 

[Werehatrack]

On 1 Sep 2004 06:34:07 -0700, [email protected] (Dave Wilson) wrote:


>I have mig, tig and gas welders, as well as a tubing notcher, chop saw
>and grinders. Plus I have access to a lathe and milling machine. And
>I know how to use them. But I have no idea how to lay out the
>geometry of a bike frame.
>
>I have thought about building a chopper to bring to the local chopper
>rally.
>http://www.floridacycling.com/Gallery Pages/Chopper041404/Chopper041404.htm
>
>Where could I find out more about designing a chopper-style bike?

Try the motorcycle info sites. The same basic principles apply,
though you'll have to adjust for the presence of the BB instead of a
motor. The main point is to get the steer axis to intersect the
ground ahead of the center point of the front tire's contact patch,
but not so far ahead that you have to expend a lot of effort to keep
the bike's fork from falling over sideways at low speeds.

If you're going to try for the low-rider style at the same time, then
the classic layout of the two-triangle frame with the BB at the base
of the seat tube won't work well at all. The BB will need to move
forward, similar to a 'bent. In fact, it would probably be easier to
adapt the common DIY-bent frame mods to produce a low-rider chopper
than to do it any other way.

I suspect that one of the frequent posters here has probably built at
least one or two such projects at some point, but given the amount of
work it takes to document what's done in such a task, I'd be very
surprised if he had time or inclination to do a full write-up. Much
of the success of such a construction task is due to the knowledge
gained in building the units that came before it; you never know when
something you discovered while building something else will turn out
to be applicable to the current beast.

If you decide to take the plunge, you're probably going to be breaking
ground on some part of your project. Be prepared to discover that
something doesn't work.

One final observation; there are a lot of reasons why chopper styling
is a temporary fad when it comes around. It is pretty much guaranteed
to produce a bike that's designed to look at, rather than to work
well. That's most of the reason why I, personally, have no plans to
build one.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Werehatrack]

On Wed, 01 Sep 2004 13:46:35 GMT, Bob
<[email protected]> wrote:

>On Wed, 01 Sep 2004 05:33:55 GMT, Werehatrack
><[email protected]> wrote:
>
>>Just lengthening the forks and bars won't do the job properly. [kersnippety]
>
>Or the approach we took as kids: Take a banana bike. Remove ft wheel
>from planned chopper. Cut the forks off any donor junk bike right at
>the top of the tube. Bang them onto your new chopper with a hammer.
>Align dropouts carefully using the ball peen eye alignment method.
>Reinstall wheel. If wheel is not centered, realign.
[more kersnip]
>
>(Not approved by the CPSC or considered safe by anyone beyond
>the age of 14)

This approach is still seen once in a while, but seldom for longer
than it takes for the rider to do a face plant. I saw a victim of
such malengineering carrying the wreckage and bearing the road rash
from such an in-flight failure several weeks ago; I think that kid
probably learned a valuable lesson about the limitations of the
technique.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Jeff Wills]

"Richard" <[email protected]> wrote in message news:<[email protected]>...
> Hello,
>
> I'm wondering if anyone can direct me on finding information on building a
> Chopper Style Bicycle?
>
> I just spent about 4 hours searching on the Net and found lots of places for
> parts, and one pictoral view of a Regular bike turned into a Chopper Style
> bike. But did not find anything more detailed.
>
> Can anyone direct me to an Online place with specs on Converting a Regular
> bike into a Chopper Style bike , (long front forks, long handle bars).
>
> Thanks in advance,

Try
http://dclxvi.org/chunk/meet/index.html
http://www.atomiczombie.com/bicycles.htm (also available in book form).

Jeff

 

[Jeff Wills]

"Richard" <[email protected]> wrote in message news:<[email protected]>...
> Hello,
>
> I'm wondering if anyone can direct me on finding information on building a
> Chopper Style Bicycle?
>
> I just spent about 4 hours searching on the Net and found lots of places for
> parts, and one pictoral view of a Regular bike turned into a Chopper Style
> bike. But did not find anything more detailed.
>
> Can anyone direct me to an Online place with specs on Converting a Regular
> bike into a Chopper Style bike , (long front forks, long handle bars).
>
> Thanks in advance,

Try
http://dclxvi.org/chunk/meet/index.html
http://www.atomiczombie.com/bicycles.htm (also available in book form).

Jeff

 

[Richard Amirault]

"Richard" wrote ...

> I'm wondering if anyone can direct me on finding information on building a
> Chopper Style Bicycle?

As an alternative .. have you seen the new STINGRAY bikes??
http://www.schwinnstingray.com/

Richard in Boston, MA, USA

 

[Dave Wilson]

Werehatrack <[email protected]> wrote in message news:<[email protected]>...
[...]
> I suspect that one of the frequent posters here has probably built at
> least one or two such projects at some point, but given the amount of
> work it takes to document what's done in such a task, I'd be very
> surprised if he had time or inclination to do a full write-up. Much
> of the success of such a construction task is due to the knowledge
> gained in building the units that came before it; you never know when
> something you discovered while building something else will turn out
> to be applicable to the current beast.
[...]

Thanks for the rapid reply. I'll see what I can find for motorcycle
geometry.

Here's a page I wrote documenting the side-by-side tandem we built for
last year's Tour de Bar. I gave it away after the event, and I hear
it's still running strong.
http://www.davewilson.cc/Welding/TourDeBar/

Those chopper bikes do look pretty unrideable. If I build one it will
probably be for one-time use.

Dave
www.davewilson.cc

 

[Werehatrack]

On Wed, 1 Sep 2004 14:15:10 -0400, "Richard Amirault"
<[email protected]> wrote:

>"Richard" wrote ...
>
>> I'm wondering if anyone can direct me on finding information on building a
>> Chopper Style Bicycle?
>
>As an alternative .. have you seen the new STINGRAY bikes??
>http://www.schwinnstingray.com/

Yes, and sillier things as well, including several 26" instances; one
of the latter had a rear wheel that would not look out of place on a
1.2L motorcycle were it not for the relatively dainty spokes. Between
the weight of the bike and the amount of tire involved, I immediately
concluded that there was no danger of our seeing them in any
competition that involved speed or climbing. (Perhaps for extreme
downhill, of the "ride it over a cliff and see how fast it falls"
variety, it might be suitable, if a trifle gaudy.)
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Chalo]

Werehatrack <[email protected]> wrote:
>
> "Richard" <[email protected]> wrote:
> >
> >I'm wondering if anyone can direct me on finding information on building a
> >Chopper Style Bicycle?
> >
> >Can anyone direct me to an Online place with specs on Converting a Regular
> >bike into a Chopper Style bike , (long front forks, long handle bars).
>
> Just lengthening the forks and bars won't do the job properly. The
> lengths and angles of the top and down tubes will still be wrong, the
> seat tube angle and/or length will be wrong, and the angle of the head
> tube will be wrong.

You miss the point that "wrong" is often just right. Here is "Babe",
my just-wrong chopper:
http://www.uploadimages.net/images/562466babesid2.JPG

She rides comparatively well and looks smashing when she's underway.

Here is a picture of one of my other choppers that has had no frame
modifications since it was a civilian bike:
http://deadbabybikes.org/bikes/choppa.htm

> If you merely put an extended fork on a
> conventional frame, it must either lift the bottom bracket and rotate
> the seat position over the rear wheel to a level that's going to make
> the bike uncomfortable (and possibly unsafe) to ride,

Hello? Why else would you even bother?

> To build a
> chopper-style bike successfully, you really need a frame that's
> specifically designed to accomodate the complementary fork.

You don't seem to grasp the cultural differences between motorcycle
choppers and bicycle choppers. Using a frame that is specifically
designed for your fork, as opposed to one you found stripped bare and
left by a dumpster, is contrary to the nature of true bicycle
choppers.

Sure, there are bicycle choppers that are really just emulating
moto-choppers, like lowrider bicycles emulate lowrider cars. But both
of those are nothing more than appendices to the larger scenes. Real
chopper bicycles are a phenomenon unto themselves. To wit:

http://scul.org/SCUL/SCUL.html
http://dclxvi.org/chunk/why/index.html
http://deadbabybikes.org/what.htm
http://www.geocities.com/ratpatrolhq/Bikes.html
http://www.crud.org/pages/ourdeal.html
http://www.scab.freeservers.com/bikes.htm

Chalo Colina

 

[Steve Kirkendall]

Richard wrote:
> I'm wondering if anyone can direct me on finding information on building a
> Chopper Style Bicycle?

Try the CHUNK 666 web site -- http://dclxvi.org/chunk/index.html
CHUNK 666 is a loose group of people in Portland who enjoy creating
(and sometimes creatively destroying) weird bikes. The web site
is more humorous than informative, but at least it's something.
Check the "technical documentation" section, and maybe "links" too.

Also, you might want to look through the "fleet" section for ideas.
I think the "springy" bikes are particularly intriguing.

 

[RonSonic]

On 1 Sep 2004 06:34:07 -0700, [email protected] (Dave Wilson) wrote:

>Werehatrack <[email protected]> wrote in message news:<[email protected]>...
>[...]
>> steering axis, producing an inadvisable fork geometry. To build a
>> chopper-style bike successfully, you really need a frame that's
>> specifically designed to accomodate the complementary fork. Modifying
>> an existing frame is possible for certain frame types, but it would
>> most likely be far cheaper to just buy a bike that's built in that
>> style to begin with unless you have the requisite metalworking
>> equipment and skills to bring to the project. (And if you have those
>> skills and equipment, the task needs little explanation.)
>
>I have mig, tig and gas welders, as well as a tubing notcher, chop saw
>and grinders. Plus I have access to a lathe and milling machine. And
>I know how to use them. But I have no idea how to lay out the
>geometry of a bike frame.
>
>I have thought about building a chopper to bring to the local chopper
>rally.
>http://www.floridacycling.com/Gallery Pages/Chopper041404/Chopper041404.htm
>
>Where could I find out more about designing a chopper-style bike?

Just between you and me, I think you're looking for a level of sophistication
that just isn't there. Looking at the examples I think the level of science
involved comes down to making chalk lines on the floor in the shape of an
interesting looking bike. Not making light of it, there's a lot of work and some
serious applied cleverness in some of those bikes, check out that wheel with two
rims laced to one hub, *****in.

I'm sorta thinking out loud here. If the head tube angle and fork geometry are
like that of a normal bike (say 70-ish degrees and some amount of rake) it won't
trip over itself and will handle like a mostly normal bike. A long fork's going
to have a much lower angle and frankly there doesn't seem to be much in the way
of rules, just have some amount of fork rake and they seem to be at least
somewhat rideable. The steeper the angle the quicker it steers. Back when I was
a kid, some guys would take a cruiser, weld a fork minus the steerer tube onto
the end of the fork and stick on a 20" wheel. Some made fork extensions from
fork legs. A very few would fabricate something like a motorcycles triple crown
and use straight fork legs. Some of these rode better than others, none of them
rode well but all were manageable. Schools used to have excellent Industrial
Arts programs where I came from. Anyway, now I'm rambling. Bottom line, I don't
think there's really much math behind it and you'll probably learn more hacking
up a pawn shop bike in an afternoon than anyone could explain in days.

I'm sure you can get a lot of your more specific questions answered for you
here. Don't know if that many people here are doing chopper stuff, but it is a
bike and they seem to know all about that, even the parts they argue about for
hours.

Ron

 

[RonSonic]

On Wed, 1 Sep 2004 09:51:52 -0400, "J. Garland" <[email protected]> wrote:

>> I'm wondering if anyone can direct me on finding information on building a
>> Chopper Style Bicycle?
>>
>> Can anyone direct me to an Online place with specs on Converting a Regular
>> bike into a Chopper Style bike , (long front forks, long handle bars).
>>
>> Thanks in advance,
>> Rich
>
>Try these guys: CHUNK 666
>http://www.dclxvi.org/chunk/index.html
>
>
>They actually have a Chopper workshop if you are in the Portland, OR area:
>http://www.dclxvi.org/chunk/operations/workshop/index.html

Fun links.

Following links off the CHUNK site we get here - fancier stuff.
http://mywilson.homestead.com/gallery0.html

Ron

 

[Menotomy]

In our Discussion Areas we have a "Customs and Choppers" section with 10 years
of info in it:

http://oldroads.com/d_low_def.asp?rec_count=1

Vin - Menotomy Vintage Bicycles, Inc.
http://OldRoads.com