Bobber Frame Blueprints Questions and Answers...

Bobber Blueprints Question Number 1: What engines will work on the frame (type of engine)?

Answer: This depends on what your taste is (if there is a specific engine you are thinking about using we can review and make sure it fits. Or you can even get your own custom drawn chopper or bobber frame blueprints).

The frame was designed with a very open area in the center. A lot of chopper frames out there have a center vertical bar from the backbone down. See photo of generic frame below...

generic bobber frame

Our chopper frame, on the other hand, does not have this. Our bobber frame does. See photo below, and see Question 3 for how to modify the bobber frame blueprints to adjust for an engine that has a transmission built in, and therefore you need to remove the center post...

bobber frame blueprints

bobber chopper frame

This gives you a lot of freedom in the size of engine and the look you are going for. Our chopper frame blueprints also give a lot of extra space for transmission as well as other features if you wish to customize the bike. I personally like the look of sheet metal styling and other features. This open frame makes it easy to customize how the engine will sit. You can locate the engine using the mounts provided on the down tubes. The concern with engine size would come into play IF there was a down tube from the backbone but since there isn't one on this frame design, it should not be a huge issue. There is plenty of space there for various sized engines.

On the other hand our bobber frame blueprints have a very unique old school look and feel. And they are a big hit. You will be limited in terms of the type of engine to use, but that might be a good thing. However you can modify it as described below.

Custom brackets would need to be attached to these mounts based on the engine size picked by you.

Also keep in mind that you can size your gas tank appropriately in order to give it the correct "look" so that it goes with your engine. That's the beauty of choppers - No two are alike!

If there is still a concern, please feel free to let us know what engine you are thinking about using and I can review and make sure it fits.

Bobber Frame Blueprints Question Number 2: Rake And Trail?

Answer: The design is definitely adaptable and the rake angle can be updated as needed. Clearance to the ground should be sufficient if you want to adjust the rake angle. If you are planning on doing a raked tree, then it should also work out fine. If you provide a rake angle along with a trail, and also a tree angle if any then we can take a look at it and see if it will all work out. Most likely this should not be a problem unless you are looking to do an extreme angle. The current design is for 40 degree rake angle and this can easily be modified by adjusting the length of the backbone. Please feel free to let us (below) know if I can provide further clarification.Would You Like A Custom Set Of Plans Created? Click here to learn more about getting your own set of custom plans designed.

Want Custom Made Bobber Frame Blueprints? Do You Want Custom Plans For Your Bike Building Project? Contact Us For A Custom Quote.

Bobber Frame Blueprints Question Number 3: Built In Tranny or Separate?

From Johnny: Hey, I bought your hard tail bobber blueprints. However I was a little excited when I bought them and started building and now I ran into a small bobber problem. I noticed after the frame is almost completely done that the bar that goes from the backbone to the crossmember is made to fit an engine that has a separate transmission! This is where my problem lies! I have a motor with the tranny built in. And it won't fit if I follow the plans as drawn know. So I was wondering if you had any tips or tricks that allow me to fit the motor I have in the frame so I don't have to start all over again? Take in account I have an 1982 Yamaha virago engine (it's about the size of a standard Sportster motor) and I have not welded the frame together completely yet. I have the backbone welded together but not to the lower half yet so I have some room to play of necessary. Thanks for all your help and I hope to hear from you soon .

Hello Johnny,

I've reviewed the design and have a few options available for you. First of all the center bar has to go so that your engine and transmission can fit. This center post plays a significant role in strengthening the frame and may compromise the overall strength if it is totally eliminated. Because of this, you'll have to add in additional support members for reinforcement. We have another frame that was designed to provide an open area in the center for large engines and transmissions. It was made for this purpose specifically. I have included a photo for you.

Frame Crossbar

What you need to do is add a straight support member from the backbone to the front part of your down rails. Make sure to adjust this so that you have enough room for the front end of your engine. The second item you'll have to do is add some support beams at the rear end on the out sides connecting the rear forks to the down rails. Please see the photos as I have add some arrows pointing to what you'll have to add. Keep in mind that the specific frame we sell has curved bars at these locations for styling. You can easily just go with a straight bar if you'd like.

frame support bar

I think your design intent was to show off the large engine and transmission. This kind of layout will do just that. Let me know if you have any other questions or would like further clarifications.


Sincerely,
Custom Choppers Guide


Didn't Get The Answers You Wanted? Ask Right Here...

What Are Your Thoughts...

What Are Your Questions, Comments, Or Suggestions On Our Bobber Frame Plans?

Enter A Title For Your Submission

Enter Your Thoughts Now...[ ? ]

Upload 1-4 Pictures or Graphics (optional)[ ? ]

Add a Picture/Graphic Caption (optional) 

Click here to upload more images (optional)

Author Information (optional)

To receive credit as the author, enter your information below.

Your Name

(first or full name)

Your Location

(e.g., City, State, Country)

Submit Your Contribution

Check box to agree to these submission guidelines.


(You can preview and edit on the next page)

What Other Visitors Have Said

Click below to see contributions from other visitors to this page...

Engine Transmission Mounts Rear End 
I want to build a chopper using your rigid chopper frame plans but I want to know if you have blueprints for a 120 s&s Harley engine, six speed baker right …

Bobber Frame For A Big Tall Guy? 
I am interested in blueprints for a bobber, but have a few requirements. I'm hoping that maybe with your experience you can lead me in the right direction. …

300 Series Bobber Soft Tail 
Just wondering if I wanted a 300 series rear tire on my soft tail bobber, how do I go about insuring that this is what I get when I order the blue prints? …

Springer and Frame Modification For 650 BSA Chopper 
I have a 1971 650 BSA and want to build a chopper from this bike. I have a complete machine and welding shop with over 50 years working in this environment. …

3 Inch Stretch On The Rigid Bobber Frame 
Hi, with the rigid bobber plans, how much will the plans cost to include a 3" backbone stretch and a 3" rear stretch (to further increase distance from …

Tall Man Body Type Bobber Frame Adjustments 
Hi. I was wondering about the ability to adjust the frames to accommodate our particular body types. For example: I'm 6'5'' with a 38'' to 40'' …

Cost of frame build? 
I'm interested in your frame plans. Can you give me a rough estimate on what it would cost to build one of your frames (materials and labor). I'm not much …

Axle Plate Width 
On your website it indicates that the bobber frame fits a 200mm tire with 10.5" clearance between plates, however the plans that I downloaded were 1" wider. …

Bobber Frame Tube Size Question 
Do you offer any frame plans that use 1.25" tubing? I'm planning on building my frame out of 1.25" tubing only because I have so much of it already laying …

1000 pound frame load? 
I'm just opening communications with your Company to make custom blue prints. Reading through more of the products literature you offer, I ran across …

Forward Controls 
I bought your bobber plans, but expected to see details of the mounting plates for the forward controls. I think I saw on your web site that you sell the …

Larger Rear Wheel  
Do you have drawing versions that allow for larger size rear wheels such as 300 series? Also wonder if you have hidden rear shock design with the 300 …

Harley Engine Bobber Frame Question 
Hi I'm after blue prints for a bobber frame which will fit a Harley engine also with a nice wide wheel at the back is there possibility you do one like …

Rubbermount twin cam 88A 
Will a rubbermount twin cam 88A and the touring transmission with the long oil pan work on this frame?

DOM and Frame Performance 
The steel terminology changes from country to country, when you say you use standard steel tubing, are you using seamed tube or dom (drawn over mandrel,seamless). …

CBR 600 engine fit? 
Will a cbr600 f2 engine fit? Here's Your Answer: Thanks for the question regarding the Honda CBR 500 F2 engine. I did some searching and found …

Plans for a vintage suzuki GS model? 
Any Bobber frames or plans for a vintage suzuki GS model? Something that would fit on old GS 750 or Gs1100 Suzuki bikes?

Bobber Open Chassis 
Yes the less the better particularly on a bobber and a lot of these are done with the sporty drive train so you definitely don't want the seat post in …

Do You Have Sportster Chopper Blueprints Like This? 
I have a Sportster 883R 2007 and I´m thinking of building a chopper like this one . Do you have a blueprint for this? Regards, Carlos.

My Bobber Frame Blueprint Comments 
Hi There! Thanks for the blueprint for the bobber frame . It looks great to me. I must admit that I´m a novice in building a custom chopper. Here in …

Laser cut specs Not rated yet
Do the bobber frame plans have specs needed to laser cut pieces?

Suzuki Frame Question Not rated yet
I have a 100% standard 1990 Suzuki Boulevard and I planned on a bobber. There's Xs, Triumph and Harley frames everywhere, but what frame can I find for …

Frame for Honda CB750 K1 engine Not rated yet
Good day, are these rigid or softail frames adaptable for a Honda CB750 K1 engine? Thanks

Plan according to Engine Type Not rated yet
I am a novice, never done a project before. My question is the frame according to a specific engine? I want to use a Honda V-Twin engine or other type …

Click here to write your own.

planning Not rated yet
I am working on putting a 4 cylinder car motor (probably a Honda) into a bike and I am wondering what kind of bobber frame would you recommend? I would …

Digital Bobber Frame Plans Not rated yet
Good day, I would like to know if you are able to send me the digital Bobber Frame plans (2D or 3D) via e-mail. I am adapting an Honda CB750-K2 engine …

Good idea! Not rated yet
This gives you a lot of freedom in the size of engine and the look you are going for. Mutahcycles Rome - Italy

Need Custom Frame Blueprints Not rated yet
I am looking for custom blueprints one for a 33 degree rake 2 inch stretch in the down tubes and a 130 mm rear and a 30 degree rake no stretch in the downtubes …

The Steering Neck And Other Questions Not rated yet
I have just started planning the building of a bobber frame from your drawing I bought from you, this is my first frame build although I have a professional …

Certificate For Frame Test Results Not rated yet
I have a question about the bobber-frame plans which I bought the 04.14. 2010. Is it possible to get a certificate of the calculation of the frame, or …

Bobber Frame Plans Look Good Not rated yet
The bobber frame plans look good. The front down tubes are nice. I like that they go parallel(good for clearing exhaust on four cylinder engines) I also …

Bobber Plans Look Fine Not rated yet
The style of the bobber plans is different than I am used to building, but everything looks fine. I will put one together and then let you know how it …

Extremely Satisfied With Bobber Blueprints Not rated yet
Needing to get the bobber blueprints enlarged some more but they are so detailed that any questions I might have had are now answered. I'm excited to …

Click here to write your own.


Bobber Frame Blueprints And Related Products:


Copyright Custom Choppers Guide All Rights Reserved.