DO THE TON

Blood Sweat Tears and Grease => Projects => Bob and Chop => Topic started by: dynamitedave on Jan 24, 2011, 13:54:01

Title: New CB350 Project - Back Breaker
Post by: dynamitedave on Jan 24, 2011, 13:54:01
I picked up a pile of shit CB350 from a motorcycle yard sale guy for next to nothing.  I really just needed the engine.
 
 I'm running out of styles for CB350s so it took me a little while to figure out the direction I wanted to go.
 
 I cut it up, lowered it, hard tailed it.  I plan to recess the seat and have a low gas tank.  Might have to make my own or cut up and reweld one I have laying around.
 
 This is what I started with.  You can see how much I lowered it in the front by the fork tubes sticking out the top 3".  I plan to run only a front brake, no back brake, the bike is so low the brake pedal would scrape when I turn.  I plan to use clip-ons mounted below the top plate of the triple tree.
 (http://dcclassiccycles.dynamitedave.com/bikes/backbreaker1.jpg)
 
 (http://dcclassiccycles.dynamitedave.com/bikes/backbreaker2.jpg)
 
 (http://dcclassiccycles.dynamitedave.com/bikes/backbreaker3.jpg)
 
 The look I'm going for.  Low and sexy.  It will prolly not handle good, be stiff, be dangerous but fuck it.  It should look cool.  I found a 19" front wheel in my shed I'm going to try to use.  This one is the stock 18" wheel.
 (http://dcclassiccycles.dynamitedave.com/bikes/backbreaker4.jpg)

DAYS LATER

I got some work done this weekend.  I mounted the seat support bars and did some sheet metal work.
 
 (http://dcclassiccycles.dynamitedave.com/bikes/backbreaker5.jpg)
 
 I bent the edges of the sheet metal by beating it with a body hammer over a round pipe to match the contour.
 (http://dcclassiccycles.dynamitedave.com/bikes/backbreaker6.jpg)
 
 Fully welded. Almost.
 (http://dcclassiccycles.dynamitedave.com/bikes/backbreaker7.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: joeficsit on Jan 24, 2011, 13:58:31
i thought cb350's came with 19" fronts?  that's good to know that some came with 18's so that i can use it on my cb200.  keep up the good work.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 24, 2011, 14:25:57
CL350s came with 19" front wheels
CB350s and CB360s all had 18" wheels.

My CB350 Bobber has a 21" front wheel that came off a '72/'73 SL350.  Uses the same street hub as the CB350s with front drum brakes.  Wish I could find some more of them.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 26, 2011, 12:44:56
I cut a 2" section out of a gas tank, looks good, need to weld it up tho.
(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker8.jpg)

Also made a little tray to recess the battery in the swing arm
(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker9.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Jan 26, 2011, 12:55:34
Wow... Well, its different for sure.
Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Jan 26, 2011, 12:56:52
Seems way too low to be rideable man. Maybe thats just because its sitting on the table though.
Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Jan 26, 2011, 12:59:06
Also... It the backbone only welded into the stamped steel at the bottom of the neck with the top just made from sheet metal?
Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Jan 26, 2011, 13:00:58
Ok, last one... Are you aware that as you have it built now, that frame is probobly going to fold in half? Not trying to be a dick, but you could really get hurt.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 26, 2011, 14:30:45
This is why I usually don't post up my bikes until they are done.  There is always someone who thinks they are a mechanical engineer.  I didn't show every little detail but the backbone is welded in the neck along with added supports, it's welded to the existing pressed sheet metal frame and tied into the main structure with added support.  The sheet metal I used is the same gauge or thicker than the existing sheet metal.  It's much stronger than a stock frame which it needs to be since this is a hard tail.

The bike is low but not too low, I rolled it outside and checked before I welded it in place.  It's too low to use the stock foot pegs since it has that bar that comes under the engine.  I'm also not running a rear brake so the pedal won't get in the way.

Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Jan 26, 2011, 14:45:40
Wow man... You dont have to be a jackass.
The fact is that if its not perfect, it can fail. Some of the things in your pics look shady. If you did more work to sure everything up, than show that too.
I never said I was an "engineer", just asking questions to look out for/help out fellow builders.
Since you apparently have it all wrapped up just fine, good. When/if it fails, I hope youre wearing a helmet.

In the end its your ass... Do whatever the hell you want. If you dont want people commenting/asking questions, dont post pics.

Best of luck.
Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Jan 26, 2011, 14:55:09
And really... Why wouldnt you just build a real hardtail anyway?
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 26, 2011, 16:22:04
Easy killer.  I don't think I was a jackass, I'm just having fun.  I'm not going to take a million pictures showing everything I do to the bike and post them up, that would take forever and be boring.  I post up pictures of good progress with the idea that viewers can use their imagination and fill in the blanks.

Build a real hardtail?  You mean buy a pre fabricated frame and bolt parts on it?  That wouldn't be any fun.  I like cutting, forming, shaping and welding metal.
Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Jan 26, 2011, 16:53:14
No. I mean a frame that doesnt use the swingarm as part of the "hardtail". Again, its your bike. Do whatever the hell you want. But if you post pics of unsafe mods, people will call you out. I also dont know of any bobber/chopper builds here that are all "bolt on" cookie cutter deals so Im not sure what that comment was about. And really man, I wasnt giving you a hard time. I was asking reasonable questions about the integrity of your frame. Seeing as you apparently have it all under control, forget I asked. Best of luck.
Title: Re: New CB350 Project - Ball Breaker
Post by: PHeller on Jan 26, 2011, 20:43:23
Despite the structural integrity of the rear frame, I'll just comment on the design.


It doesn't look cool. I don't like seeing the swingarm joints. The whole rear looks pretty messy. I'm not seeing any flow to the lines, not only that it doesn't have the cool "open area" left in the rear frame on a proper hardtail.


The front is pretty rad though. Nice call on the tank chop and hiding the front frame gussets.


I'd try to simplify the rear and make it flow with the front frame sections.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 26, 2011, 22:55:07
I left the swing arm in tact for ease of building.  Leaving the swing arm mounted ensures the back tire winds up where isn't supposed to, also ensures the sprockets line up and the tire is true horizontally and vertically.  Someday I'll build a jig to hold everything in place for now I did it this way. 

The "open area" you call cool looks ridiculous to me.  I don't like when they stretch out the bikes and have a big voided space between the rear wheel and engine. 

I think it will all come together when the bike is painted and all the parts are on it.  Most people won't even notice the swing arm is bolted in.
Title: Re: New CB350 Project - Ball Breaker
Post by: Ringo on Jan 26, 2011, 23:18:07
The swinger was the first thing I noticed too.  Again, like everyone here, not trying to be a dick, but when you spend that much time welding up the frame...and leave the swing arm...?  It looks like any other half-assed "hard tail" people post up.  Give yourself some credit and don't cut that corner.  I know I would regret it down the road when I admired my bike.  Hope you don't!
Title: Re: New CB350 Project - Ball Breaker
Post by: Slice on Jan 27, 2011, 11:50:22
There is clearly a lot of questions surrounding the safety of this build... You question it yourself in your first post when you say "It will prolly not handle good, be stiff, be dangerous but fuck it. " Having said that, you already understand that fact, so no one needs to point it out to you.
From an aesthetic persepctive, i cant see what it will look like but I have a feeling its not going to be my 'bag of tricks'... however, to each their own!
Good luck man.

Slice
Title: Re: New CB350 Project - Ball Breaker
Post by: Beard on Jan 27, 2011, 11:55:25
just weld the swingarm solid
 
im guessing u dont want the front of ur seat angling down...
so add another pipe from the rear to the main frame beam to level out your seating.
then cross ur fingers
 
 
running without a 2nd brake... is sketchy.
 
may i suggest these
(http://www.specialfootwear.co.uk/images/fun_yellow_350.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: tWistedWheelz on Jan 27, 2011, 12:34:02
I think this whole thing has been blown way out of proportion! I think the work done on the rear end is structurally sound given you add some gussets, which I am sure you plan on doing. I see no problems with your welds, they look great and I think you have ample support for the rear end. If it were me, I would leave the swinger as you have for my jig and then weld another tube from the bottom frame rails back to the swinger just in front of the axel and lose the rest of the swinger then. The structure will be supported then and no longer require the swinger for a jig, and that may very well be your plan. Where the work does raise concern to me is the top part of the frame where it meets the neck. I think with all the work you are doing and the skill you have, it would be no problem for you to get rid of all that stamped steel and put in a solid tube spine. Once that and the swinger are removed you could gusset up and clean up the old lower backbone area that is stamped steel. As far as being unsafe, well I am not sure if it is or is not with what you have done on the neck area, I simply can't tell from photos what all work you have done there, but I do know that a solid single tube would clean it all up nice and offer you better support than the old stamped steel. I really dig that low seat and it seems to me that with the one added support I mentioned, you would actually have more support that needed to be safe there. I hope all of this lashing you have received does not hinder you from this site or from showing us your work. This is a really nice bunch here and sometimes as a regard to safety, some people can come across wrong. Text does not carry attitude with it well sometimes, and it may come across derogatory when it was intended to be constructive. Good luck on your build. I will be excited to see what you come up with!

Cheers,
Brandon
Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Jan 27, 2011, 12:59:21
The problem is Brandon that there is no "neck tube" on a 350. Its all stamped steel. Just a few layers of it. When you cut that away, its nearly impossible to make it strong enough. And honestly, I wasnt trying to give you a hard time man. I just dont want to see ya put a ton of time/effort into a build and have it be dangerous or unrideable. Im down with your effort to do something different than whats out there. Just didnt want to see it be a futile effort.
Title: Re: New CB350 Project - Ball Breaker
Post by: tWistedWheelz on Jan 27, 2011, 13:08:28
I am aware of the factory construction of stamped steel on the backbone and stamped steel that forms the neck of a Honda CB350 Mike, and if you read my post you will see where I offered the advise to remove all of that and replace it with steel tube to make it stronger than even the stock one would be, which does really need the reinforcement of a stronger backbone once you convert to a rigid design. I think Dave has enough info here to make an educated decision and further discussion is just unnecessary. He apparently is a skilled fabricator and has an understanding of what is needed. I am sure he is a reasonable man and will work well with the help of suggestion from others who have offered him the suggestions.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 27, 2011, 13:38:41
Thanks Brandon.  I thinks been a little over blown as well.  I do plan on adding some gussets later in the project.  I will keep the swing arm in place.  Ultimately it adds more strength since it completes a triangle and now it's going to hold the battery and the rest of the needed electronic will be placed just above the battery.  The seat bars are angled because of where I wanted them mounted to the main downtube.  They are welded to the wide area of the tube, directly above them the tube gets narrower.  I will level the seat out with padding.  I'm not planning on running a spring seat.
I'm not going to write more about the top tube.  It's thick steel, fully welded, creates triangulation.  I'm leaving the rest of the stamped frame in place to hold the spark plug thingies. Most of it's hidden and it's plenty strong.  Once I get the mock up done I'll strip the bike, fully weld the frame, add some gussets and paint it.
Title: Re: New CB350 Project - Ball Breaker
Post by: tWistedWheelz on Jan 27, 2011, 14:11:19
Dave I think the real concern here is the fact that the factory stamped steel got its real strength from the welded creased seam, and you have eliminated that. I am not saying your design is bad, or wrong, only that you removed a good bit of strength from the stock setup. Since there is not real "tube" in the neck, remaking that area with sheet metal will never offer you good strength, especially on a rigid. I would suggest welding in a proper tube up there for the neck, then making your triangle with another piece of short tubing from the top of the new neck tube back to the backbone. This will tie it all up real nice and give you ample strength. The real problem with the factory construction of the stamped steel is its lack of strength, and without the crimped welded ridge, it is way too flimsy for your type of build. Like I said, that is just what I would do, and I think everyone who has worked on a similar project here would agree on that. It is something you may want to consider. As for the swinger end, well it does complete the triangle and if you welded in a tube piece on both sides from the bottom of the frame back to the swinger, it would also create the triangle and be more aesthetically pleasing than a swing arm. Just another suggestion though.
Title: Re: New CB350 Project - Ball Breaker
Post by: tWistedWheelz on Jan 27, 2011, 14:18:25
This is what I mean on the back end. The red will be the new piece of tube and the green (hard to see) would be a gusset that ties the triangle in tight and allows you to weld some of the cut off swing arm back to it for added strength. I think it would just look better and you could build a battery tray on the back side of the old backbone and mount other electrics to the side of it.
(http://i230.photobucket.com/albums/ee5/mk25diver/backbreaker7.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 27, 2011, 14:43:32
factory stamped steel got its real strength from the welded creased seam, and you have eliminated that.

I did eliminate the welded seam but I welded in flat strips to hold the 2 pieces together.  You can't see it in any picture tho.

The gusset you drew in the picture is far too large and would look silly.  I think if you guys could see what I really did and all the places I welded and added extra supports in person it wouldn't be an issue.  I do plan on welding in a small gusset where you show it but I think the red bar is overkill unless I remove the swing arm which I doubt I will do.
Title: Re: New CB350 Project - Ball Breaker
Post by: tWistedWheelz on Jan 27, 2011, 14:48:47
Your build brother and by no means am I telling you what to do, I am only offering you suggestions. If it puts a smile on your face man, and it is safe, I am just as happy as you when it is done! I am here to offer ideas and receive them. I have learned a lot here and I only try to give back because of all I have gotten. Good on you for doing it your way man. To each his own and that is what a custom motorcycle is all about. If we built them all the same, they would not be custom at all. Keep up the work, I am very interested to see you final product!
Title: Re: New CB350 Project - Ball Breaker
Post by: Beard on Jan 27, 2011, 15:11:53
i still vote no brakes period..
and the big shoes..
Title: Re: New CB350 Project - Ball Breaker
Post by: tWistedWheelz on Jan 27, 2011, 15:22:39
  I'm leaving the rest of the stamped frame in place to hold the spark plug thingies.

I hope that the phrase you used "spark plug thingies" is a joke! And why not run a rear brake, all the stuff for it is still there. As far as the gusset I put on the illustration, well it was just to give you an idea. But if you think it looks silly that is your opinion and you are intitled to it, IMO a swingarm on a rigid not only looks silly but sounds silly too!
Title: Re: New CB350 Project - Ball Breaker
Post by: dakine_surf on Jan 27, 2011, 15:56:00
But if you think it looks silly that is your opinion and you are intitled to it, IMO a swingarm on a rigid not only looks silly but sounds silly too!

Bahahahaha +1
Title: Re: New CB350 Project - Ball Breaker
Post by: Dead Bound on Jan 27, 2011, 17:59:17
When did this turn into caferacer.net ?
 
Though, I would vote for a regular hardtail if it was in the poll. 
Title: Re: New CB350 Project - Ball Breaker
Post by: boisdarc on Jan 28, 2011, 19:24:13
First, I love net warriors-but I've never met one in person. Having said that, I understand what you mean-a large empty void section of a traditional hard tail DOES look like crap. DRAGON from JJ always harped on that. You can fill that section with your electronics or battery or even an external oil filter or whatever. Some people(myself included) think that a non traditional hardtail made from a swing arm looks kind of lame and half way done. I think that the folks here looked at your pictures and their initial glance made them think that your hardtail is not structurally sound and they were trying to look out for your best interest. Everyone here that I have pm'ed or im'ed has been more than helpful and polite.
Title: Re: New CB350 Project - Ball Breaker
Post by: overdraft on Jan 28, 2011, 19:45:06
When did this turn into caferacer.net ?
HAHAHAHA! this made my day! i gave up over there cuz they seem to take pleasure in cutting people down.

i'm a cafe guy so i rarely roam over here, but if this is the bob and chop section then chop away! interesting stuff!
Title: Re: New CB350 Project - Ball Breaker
Post by: fastbroshi on Jan 28, 2011, 19:53:47
I doubt you're using this thing for land speed records or to rail at the track.  You should be fine as long as the integrity of your welds is solid and your tires/wheels are sound.  And I'm sure you're addressing the forks and steering bearings.   If you were bobbing a Schwinn frame I'd be concerned however.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 30, 2011, 10:56:26
I looked at the bikes on caferacer.com.  They are fugly.  My bike is pretty.

I did some sheet metal work around the seat pan.  I mounted the brackets that hold the electronic components that I need.  I also put in some gussets. 

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker10.jpg)(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker11.jpg)
(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker12.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: blue44067 on Jan 30, 2011, 12:59:38
my bike has a "half assed hard tail" too, just struts welded to my swinger and to the seat bars I really like your design. What is that tank from? One thing I've noticed with mine is that the back wheel seems to wander under the bike at high speed on gravel roads. I think its because I haven't welded the swing arm to the frame, and my struts are too small in diameter. Anyways, I like the look you've got going there.
(http://i1182.photobucket.com/albums/x460/blue44067/DSC04173.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: KeninIowa on Jan 30, 2011, 13:11:43
Considering some of what I've seen it's hard to understand why this bike started the unsafe dogpile.

SO safety dudes, assuming proper welding/fitment techniques, where's the fail point of the hardtail?

I can't tell from the pics how well the neck's tied back in.   That's the much larger issue, but I get from this the OP at least understands the concept;

 
the backbone is welded in the neck along with added supports, it's welded to the existing pressed sheet metal frame and tied into the main structure with added support.  The sheet metal I used is the same gauge or thicker than the existing sheet metal.  It's much stronger than a stock frame which it needs to be since this is a hard tail.

I agree stock rake/stretched hardtaills look silly.
Title: Re: New CB350 Project - Ball Breaker
Post by: Dead Bound on Jan 30, 2011, 19:32:37
I looked at the bikes on caferacer.com.  They are fugly.  My bike is pretty.

I didn't mean anything about your bike.  I meant the people on there are less than helpful when it comes to a build.         
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 30, 2011, 22:33:47
my bike has a "half assed hard tail" too, just struts welded to my swinger and to the seat bars I really like your design. What is that tank from? One thing I've noticed with mine is that the back wheel seems to wander under the bike at high speed on gravel roads. I think its because I haven't welded the swing arm to the frame, and my struts are too small in diameter. Anyways, I like the look you've got going there.

I think hard tails would tend to wonder on gravel most of the time.  Your struts look a little narrow.  I would use the same thickness tube as most of the frame.  Lower rear tire pressure and a well balanced tire may help with the wondering of the tire.  The tank on my bike is a stock '70-71 CB350 tank with a 2" section removed from the middle horizontally. 
Title: Re: New CB350 Project - Ball Breaker
Post by: Ringo on Jan 31, 2011, 06:34:13
my bike has a "half assed hard tail" too, just struts welded to my swinger and to the seat bars I really like your design. What is that tank from? One thing I've noticed with mine is that the back wheel seems to wander under the bike at high speed on gravel roads. I think its because I haven't welded the swing arm to the frame, and my struts are too small in diameter. Anyways, I like the look you've got going there.

There could be several causes for this, but... did you replace the swing arm bushings when you got the bike?  Worn bushings will give you a sloppy rear end.  Welding the swing arm to the frame could help if this was your problem.  Please do not deflate your tires.  Underinflated tires can cause tire failure.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Jan 31, 2011, 23:05:14
I need some parts.  I am looking for a disk brake front rim with little to no rust and forks that are disk brake compatible and have little to no rust.  Anyone have any extras?
Title: Re: New CB350 Project - Ball Breaker
Post by: motofiaccone on Feb 01, 2011, 10:53:36
Wow!
Title: Re: New CB350 Project - Ball Breaker
Post by: blue44067 on Feb 01, 2011, 22:16:31
 :o  only on my wife's birthday! ;)
Title: Re: New CB350 Project - Ball Breaker
Post by: JustinLonghorn on Feb 02, 2011, 09:18:23
I have a cb360 front rim with a newer tire on it, if you are interested.

Here is a pic:

(http://img.photobucket.com/albums/v38/wetherbe/front_wheel.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: baby elephant guy on Feb 04, 2011, 16:45:40
my bike has a "half assed hard tail" too, just struts welded to my swinger and to the seat bars I really like your design. What is that tank from? One thing I've noticed with mine is that the back wheel seems to wander under the bike at high speed on gravel roads. I think its because I haven't welded the swing arm to the frame, and my struts are too small in diameter. Anyways, I like the look you've got going there.
(http://i1182.photobucket.com/albums/x460/blue44067/DSC04173.jpg)

i dig that tank!
Title: Re: New CB350 Project - Ball Breaker
Post by: baby elephant guy on Feb 04, 2011, 16:53:34
oppps wrong picture
Title: Re: New CB350 Project - Ball Breaker
Post by: sxecafe on Feb 06, 2011, 14:28:46
i still vote no brakes period..
and the big shoes..

I agree. Clearly the best option.
Title: Re: New CB350 Project - Ball Breaker
Post by: barnicle on Feb 08, 2011, 14:05:38
So I just want to remind everybody this is the bob/chop section nothing that happens hear ends up being better or safer than it was in the beginning.
Once you have made you comments, and its clear the builder is committed to his design, butt out, and let the man build!
Title: Re: New CB350 Project - Ball Breaker
Post by: motofiaccone on Feb 08, 2011, 16:54:30
So I just want to remind everybody this is the bob/chop section nothing that happens hear ends up being better or safer than it was in the beginning.
Once you have made you comments, and its clear the builder is committed to his design, butt out, and let the man build!

That was magnificently said!

Von:

I agree with you, man; I do. But I think you're pissing in the wind here. My concern is when the bike fails--and it will--increased regulation on homebuilders will occur. It's something we're up against anyway.

This design is so fundamentally far from reasonable and prudent, you gotta smile man. You do. Natural selection always manifests.

--Chris
Title: Re: New CB350 Project - Ball Breaker
Post by: LOCKARD666 on Feb 08, 2011, 17:25:28
that 2" section does look badass in that tank... i just hope it doesn't get fucked up when the frame breaks :P
Title: Re: New CB350 Project - Ball Breaker
Post by: KeninIowa on Feb 08, 2011, 20:07:33
when the bike fails--and it will
--Chris

Where and why? 
 
 
Title: Re: New CB350 Project - Ball Breaker
Post by: motofiaccone on Feb 08, 2011, 20:33:49

Where and why? 
 
 

Seriously? Look at the load paths on this thing. As the neck gets loaded vertically, the bending moment is exactly where the backbone is preloaded--out of sheet metal. That's going to force those tiny upper engine mounts down and will ultimately fail. One pothole or a rough railroad crossing will ensure that will happen. But that's nothing...

In the font, at least there is a dampening mechanism to, well, dampen the load on the neck. In the rear, the wheel will take infinitely variable shock loads as the wheel bounces down the road. Introduce a pothole or some other traumatic bump--which we see everyday whilst riding--and that upper mount gets jammed into the backbone, again at the bending moment. That backbone? .090" sheet metal which is trying to buckle in it's stock form. We're not talking massive speeds or overly traumatic loads here. A 250lbs man just sitting on the bike could do the trick.

Really, I don't care. The more I look at it, the more I realize the catastrophic event will happen close to home and at very low speeds. My hope is that we at least get video or photo evidence of the bike and no one gets hurt.

http://i230.photobucket.com/albums/ee5/mk25diver/backbreaker7.jpg (http://i230.photobucket.com/albums/ee5/mk25diver/backbreaker7.jpg)

--Chris
Title: Re: New CB350 Project - Ball Breaker
Post by: KeninIowa on Feb 08, 2011, 22:34:45
All that sounds serious. 

What's a load path?

Can they be fixed?

Seems unkind to not care about another motorcyclist experiencing catastrophic failure, albeit close to home and at hopefully a slow speed.

WWCFD?

Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Feb 08, 2011, 23:08:03
People have stated concern and were ignored...
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Feb 09, 2011, 00:36:14
I'm not even going to bother arguing with you guys.  The frame is good, the bike isn't going to break in half.  Shut up and enjoy the pictures.
Title: Re: New CB350 Project - Ball Breaker
Post by: VonYinzer on Feb 09, 2011, 11:24:54
Hahaha... Ok man.
Title: Re: New CB350 Project - Ball Breaker
Post by: Flugtechnik on Feb 09, 2011, 12:07:05
Chris, with all this fancy talk about loadpaths, it sounds like you should be in my line of work.  We could use more people that actually understand loadpaths.  I agree with your assessment.  The piece under the "seat" punching into the middle of the downtube will bring about a quick fatigue failure.  But it is his bike.  As my mentor said, "You can't push a rope."

I'm not even going to bother arguing with you guys.  The frame is good, the bike isn't going to break in half.  Shut up and enjoy the pictures.

Well said Dave.  We will enjoy the pics.  Keep them coming.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Feb 09, 2011, 14:28:28
I usually don't post very little thing I do on forums. I post a little text and some pictures and let you guys fill in the blanks with the hope that you guys will just assume the fabrication is good.  Clearly some of you have more time on your hands and  need more hand holding than I would generally provide.

Here is a picture I colored on to show what I feel are the load paths, dynamic and equalizing.  It shows gussets and load distributing triangles.  It shows the dynamic load (green arrows) going up the frame from the start point of the load at the rear tire assuming the pivot point of the load would be the location of the stock swing arm support.  It also shows the equalizing load path (orange arrows) that will travel through the gussets and supports to distribute the load and prevent failure.  In the picture below "A" is assumed to be the failure point if failure was to occur.  What you can't see and what motofiaccone assumed wasn't there is a plate that runs above and below the point of attachment to distribute the load.  Not that the load at point A would be that significant since the load is being distributed along the path of the orange arrows.

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker_load_path.jpg)

That backbone? .090" sheet metal which is trying to buckle in it's stock form.
The backbone has sheet metal in the construction (area "B" above) of it but unlike a stock CB350 there is a 1.25" steel tube (3/16" wall thickness) that is welded into the neck and is fully welded through the remaining stock lower backbone (where the top engine mount is) and then welded to the down tube at the rear of the engine.  There is also extra support connecting the pipe to the neck that was not shown on this thread.  The sheet metal piece I welded in is 16 gauge (approx. 1/16" or 0.06" thick which it comparable or better than stock) and is welded to the neck and along the backbone that I put in.  The angle of the triangle that the sheet metal makes is appropriate to distribute the load along the backbone of the bike.  If the angle was too steep it would not provide enough rigidity to support the load.  The shape made is almost a perfect geometrical triangle.

A 250lbs man just sitting on the bike could do the trick.
This thing isn't cardboard, its steel.  Do you really think a 250lbs man just sitting on the bike would cause the frame to break?  Seriously?  I'm only 170lbs so I guess I'm good to go right?

Feel free to get your crayons out and color on a picture of the bike if you want but ultimately without seeing what I have done in person and the steps I have taken to ensure the rigidity of the frame you have no sold platform to base your unfounded opinions on now do you?
Title: Re: New CB350 Project - Ball Breaker
Post by: motofiaccone on Feb 09, 2011, 14:46:36
I certainly appreciate some quick research, but you're off on so many different fronts. I don't even know where to begin. You don't really get this stuff (chopping up a swing arm is a good example). And that's OK. Really.

Again, I don't want to get into a pissing contest, but I've seen pictures of fat girls. I don't need to see them in person to know they're fat. A photo does just fine. Same with you bike. A photo suffices.

You've got 27 posts on this forum and knowledgeable and long-time contributors are offering constructive criticism. This is a pretty positive forum with people who sincerely want to help others. Some people get it and others don't. And that's OK too.

--Chris
Title: Re: New CB350 Project - Ball Breaker
Post by: KeninIowa on Feb 11, 2011, 21:36:58
but you're off on so many different fronts. I don't even know where to begin.

--Chris

Pick one, I'd like to learn
Title: Re: New CB350 Project - Ball Breaker
Post by: MotorbikeBruno on Feb 20, 2011, 17:37:54
I've never chopped anything too crazily so I'd like to hear more too!  Motofiaccone definitely has his stripes when it comes to motorbikes, so don't take his words as arrows or bullets...he's actually concerned for your well being, as am I and probably the entire site.  I'll offer this up to Moto....can it be fixed at this point?
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Sep 23, 2011, 10:47:04
The project is nearly done.  I have a couple small things to do still but it's close enough done to post.  I have a new headlight for it but it's missing parts.  I might keep this one for awhile.


(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker13.jpg)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker14.jpg)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker15.JPG)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker16.JPG)

My roommate sitting on the bike trying to show how low it really sits.
(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker18.jpg)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker20.jpg)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker21.JPG)
Title: Re: New CB350 Project - Ball Breaker
Post by: d20mox on Sep 23, 2011, 12:12:39
Lot of breaking balls going on in this thread, that's for sure.

Title: Re: New CB350 Project - Ball Breaker
Post by: barnicle on Sep 23, 2011, 13:04:37
thanx for posting I was afraid the know-it-alls had chased you off. grats on the finish
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Sep 26, 2011, 11:12:23
Well usually the know-it-alls - don't.
Title: Re: New CB350 Project - Ball Breaker
Post by: motofiaccone on Sep 26, 2011, 22:15:31
Well usually the know-it-alls - don't.

Yeah? Put a 1000 miles on that and report back.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Oct 17, 2011, 00:54:35
Honda CB350 Custom (http://www.youtube.com/watch?v=Oi4q8fvocYM#)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker0_5.JPG)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker0_8.JPG)
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Oct 23, 2011, 23:09:36
Frame tested by Steve the giant.

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker__2.jpg)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker__3.jpg)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker__4.jpg)

(http://dcclassiccycles.dynamitedave.com/bikes/backbreaker__5.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Feb 23, 2012, 17:18:45
More fun with friends.


(http://dcclassiccycles.dynamitedave.com/rides/vintage_day1.jpg)


(http://dcclassiccycles.dynamitedave.com/rides/vintage_day3.JPG)


(http://dcclassiccycles.dynamitedave.com/rides/vintage_day5.JPG)


(http://dcclassiccycles.dynamitedave.com/rides/vintage_day8.JPG)


http://www.youtube.com/watch?v=YCV6ONveWuw (http://www.youtube.com/watch?v=YCV6ONveWuw)

Title: Re: New CB350 Project - Ball Breaker
Post by: sinbad85 on Feb 23, 2012, 19:10:49
looks solid enough too me! well done mate.....
congrats on finishing it with all the negativity on here!
keep on truckin'
Title: Re: New CB350 Project - Ball Breaker
Post by: MotorbikeBruno on Feb 23, 2012, 21:00:07
looks solid enough too me! well done mate.....
congrats on finishing it with all the negativity on here!
keep on truckin'

Really?  Negativity?  I think the bike looks great, I agree that its definitely different and I too enjoy it.  But to say the above comments are negativity...come on, think with your head.  The above comments are from others in the industry that build bikes too.  They aren't attacking him for who he is, or anything, they are giving advice that concerns someones well being.  Negativity says your bike sucks (which nobody said here) and again I think it looks pretty cool.  I'm glad you are doing well Dynamitedave, ride on sir!
Title: Re: New CB350 Project - Ball Breaker
Post by: barnicle on Feb 24, 2012, 11:36:28
A few people must have removed comets, if there are only constructive comments posted currently.  :-X glad to see you got it on the road. my 360 still wont run on both cylinders :'(.
Title: Re: New CB350 Project - Ball Breaker
Post by: CooperSmithingCo on Feb 24, 2012, 13:24:22
Great looking bike, looks fun and congrats!

The swingarm pivot is past the point of triangulation, which means the load would first have to travel down the overlapping tube - the pivot is in tension, the other tube in compression. With the seat rails completing the triangle, there's just no way you could apply enough force to the rear end to break anything.

Many will stick their toes out from the sidelines just to say they were in the game. Keep building and don't let them trip you up.
Title: Re: New CB350 Project - Ball Breaker
Post by: MotorbikeBruno on Mar 22, 2012, 10:30:23
http://minneapolis.craigslist.org/dak/mcy/2915422829.html

Saw this today and thought of yours (you did a much better job though!)

Title: Re: New CB350 Project - Ball Breaker
Post by: CurtisR on Mar 28, 2012, 19:40:22
I really like the look of this one.
Props!
Title: Re: New CB350 Project - Ball Breaker
Post by: soichiro on Apr 19, 2012, 17:14:13
I really like the looks of this one too.  Inspirational.  Makes me want to make a similar one for myself.   :)
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Apr 23, 2012, 01:32:02
Thanks for the comments guys. I have gotten good response form people who see it in person and anyone who rides it, loves it.

A buddy and I did a 70 mile group ride with it and my bobber last weekend.  We had a great time.  The seat is a little rough but managable.  I have many more projects planned.  I have 5 CB/CL350s that need to be built still. 


(http://dynamitedave.com/dcsportbikes/church-street-cafe/church_cafe_ride12.JPG)


(http://dynamitedave.com/dcsportbikes/church-street-cafe/church_cafe_ride15.JPG)


(http://dynamitedave.com/dcsportbikes/church-street-cafe/church_cafe_ride18.JPG)


(http://dynamitedave.com/dcsportbikes/church-street-cafe/church_cafe_ride20.JPG)


(http://dynamitedave.com/dcsportbikes/church-street-cafe/church_cafe_ride23.JPG)

Title: Re: New CB350 Project - Ball Breaker
Post by: 8ighty1ne on Apr 30, 2012, 21:09:08
i just got done reading this entire thread...oh man.

i just realized the VA plates on your bike..where are you located?  Im in Centreville, Fairfax area

let the haters hate homie. 
Title: Re: New CB350 Project - Ball Breaker
Post by: CurtisR on May 01, 2012, 01:07:31
I think it's just cause it's so different.
But, I love looking at your bike.
Title: Re: New CB350 Project - Ball Breaker
Post by: ryanglade on May 01, 2012, 01:20:07
maybe I missed it somewhere but who did your leatherwork on the seat?
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on May 03, 2012, 12:16:13
I live in Woodbridge and work in DC.  I hang out in Centerville/Fairfax sometimes. 

I did the leather work on the seat.  It was my first one.  It's a lot harder to do than it looks online.  I bought some leather and tools from http://www.tandyleatherfactory.com (http://www.tandyleatherfactory.com) and tried it out.  I made templates out of poster board, then cut the leather, punched holes in it and hooked the pieces together with leather shoe laces I got at the grocery store.  Then I died the leather, black cheery is the color I think.
Title: Re: New CB350 Project - Ball Breaker
Post by: 8ighty1ne on May 03, 2012, 21:59:13
Sweet man, ive been riding street bikes forever and this is my first little "kicker" bike...id love to go out on a ride like that sometime..looks like middleburg area or paris to me..hit me up!
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on May 18, 2012, 13:21:55
Little gathering last night with the boys.

http://www.youtube.com/watch?v=K-qmp1pNdw4
Title: Re: New CB350 Project - Ball Breaker
Post by: 8ighty1ne on May 19, 2012, 00:46:32
this is my late week at work and i couldnt make it out, looked like fun though.
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Oct 17, 2012, 15:26:17
We hit the tail of the dragon last week.  Made Killboy's highlights. 


(http://dcclassiccycles.dynamitedave.com/trips/dragon2012/killboy1.jpg)


(http://dcclassiccycles.dynamitedave.com/trips/dragon2012/killboy2.jpg)


(http://dcclassiccycles.dynamitedave.com/trips/dragon2012/killboy3.jpg)
Title: Re: New CB350 Project - Ball Breaker
Post by: SloKrt on Oct 20, 2012, 00:49:21
Nice bike, looks like a fun ride!
Title: Re: New CB350 Project - Ball Breaker
Post by: dynamitedave on Mar 31, 2016, 12:23:07
The bike is still going strong.  It's five years old this year.
I took it out the other day and stopped by Bel Air, a house near me that was built in 1740. 

(https://scontent-lga3-1.xx.fbcdn.net/hphotos-xlp1/v/t1.0-0/p526x296/1688614_10153350564225443_943719001378217988_n.jpg?oh=45381e3bbf508ca528fa089af67d5f70&oe=5778CB99)
Title: Re: New CB350 Project - Back Breaker
Post by: dynamitedave on Jun 29, 2018, 15:51:35
I hit the dragon again last weekend. The bike still running great 6 years after being built.
Title: Re: New CB350 Project - Back Breaker
Post by: WhyNot on Jun 30, 2018, 10:11:04
Dayyyyyum....I like it.

Wanta build me one? I got a SL350 frame CB350 engine and 2 wheels, that's a start...........!

Cool looking and glad it's still running.
Title: Re: New CB350 Project - Back Breaker
Post by: Popeye SXM on Jun 30, 2018, 18:13:56
I just read through everything.... Wow you got some shit. I think the bike looks cool and if your fab work is as good as I can see in the pics then the hater's have been proven wrong. Congrats on that!! It does look a little hard on the but & balls, the price of looking cool? Great bike, pleased to see it is still being enjoyed
Title: Re: New CB350 Project - Back Breaker
Post by: MiniatureNinja on Jun 30, 2018, 22:01:01
I just read through everything.... Wow you got some shit. I think the bike looks cool and if your fab work is as good as I can see in the pics then the hater's have been proven wrong. Congrats on that!! It does look a little hard on the but & balls, the price of looking cool? Great bike, pleased to see it is still being enjoyed

I love seeing the beginning stages of old threads - there are some AWESOME amazing builds that got shit talked for the first 3-4 pages. This bike is awesome and I really enjoyed the thread, thanks!!!

I especially love this one - wherever you are motofiaccone... I hope you're hungry.
Yeah? Put a 1000 miles on that and report back.

Title: Re: New CB350 Project - Back Breaker
Post by: dynamitedave on Jul 02, 2018, 13:23:52
Thanks. The seat is a little rough now that I'm older and fatter. I think I will improve it a little soon. My tailbone hits the back part of the seat so I think I'll add more padding and redo the leather.  The bike has great ergonomics though.